FAA

-H-8083-3A

AIRPLANE FLYINGHANDBOOK

2004

U.S. DEPARTMENT OF TRANSPORTATIONFEDERAL AVIATION ADMINISTRATION

Flight Standards Service

Front Matter.qxd 5/7/04 10:45 AM Page i

ii

Front Matter.qxd 5/7/04 10:45 AM Page ii

iii

PREFACEThe Airplane Flying Handbook is designed as a technical manual to introduce basic pilot skills and knowledge thatare essential for piloting airplanes. It provides information on transition to other airplanes and the operation ofvarious airplane systems. It is developed by the Flight Standards Service, Airman Testing Standards Branch, incooperation with various aviation educators and industry.

This handbook is developed to assist student pilots learning to fly airplanes. It is also beneficial to pilots who wishto improve their flying proficiency and aeronautical knowledge, those pilots preparing for additional certificates orratings, and flight instructors engaged in the instruction of both student and certificated pilots. It introduces the futurepilot to the realm of flight and provides information and guidance in the performance of procedures and maneuversrequired for pilot certification. Topics such as navigation and communication, meteorology, use of flight informationpublications, regulations, and aeronautical decision making are available in other Federal Aviation Administration(FAA) publications.

This handbook conforms to pilot training and certification concepts established by the FAA. There are different waysof teaching, as well as performing flight procedures and maneuvers, and many variations in the explanations ofaerodynamic theories and principles. This handbook adopts a selective method and concept of flying airplanes. Thediscussion and explanations reflect the most commonly used practices and principles. Occasionally the word “must”or similar language is used where the desired action is deemed critical. The use of such language is not intended toadd to, interpret, or relieve a duty imposed by Title 14 of the Code of Federal Regulations (14 CFR).

It is essential for persons using this handbook to also become familiar with and apply the pertinent parts of 14 CFRand the Aeronautical Information Manual (AIM). The AIM is available online at http://www.faa.gov/atpubs.Performance standards for demonstrating competence required for pilot certification are prescribed in the appropri-ate airplane practical test standard.

The current Flight Standards Service airman training and testing material and subject matter knowledge codes for allairman certificates and ratings can be obtained from the Flight Standards Service Web site at http://av-info.faa.gov.

The FAA greatly acknowledges the valuable assistance provided by many individuals and organizations throughoutthe aviation community whose expertise contributed to the preparation of this handbook.

This handbook supersedes FAA-H-8083-3, Airplane Flying Handbook, dated 1999. This handbook also supersedesAC 61-9B, Pilot Transition Courses for Complex Single-Engine and Light Twin-Engine Airplanes, dated 1974; andrelated portions of AC 61-10A, Private and Commercial Pilots Refresher Courses, dated 1972. This revision expandsall technical subject areas from the previous edition, FAA-H-8083-3. It also incorporates new areas of safety con-cerns and technical information not previously covered. The chapters covering transition to seaplanes and skiplaneshave been removed. They will be incorporated into a new handbook (under development), FAA-H-8083-23,Seaplane, Skiplane and Float/Ski Equipped Helicopter Operations Handbook.

This handbook is available for download from the Flight Standards Service Web site at http://av-info.faa.gov. Thisweb site also provides information about availablity of printed copies.

This handbook is published by the U.S. Department of Transportation, Federal Aviation Administration, AirmanTesting Standards Branch, AFS-630, P.O. Box 25082, Oklahoma City, OK 73125. Comments regarding this hand-book should be sent in e-mail form to AFS630comments@faa.gov.

AC 00-2, Advisory Circular Checklist, transmits the current status of FAA advisory circulars andother flight information publications. This checklist is available via the Internet athttp://www.faa.gov/aba/html_policies/ac00_2.html.

Front Matter.qxd 5/7/04 10:45 AM Page iii

iv

Front Matter.qxd 5/7/04 10:45 AM Page iv

v

Chapter 1—Introduction to Flight TrainingPurpose of Flight Training.............................1-1Role of the FAA ............................................1-1Role of the Pilot Examiner ............................1-2Role of the Flight Instructor ..........................1-3Sources of Flight Training.............................1-3Practical Test Standards.................................1-4Flight Safety Practices...................................1-4

Collision Avoidance..................................1-4Runway Incursion Avoidance...................1-5Stall Awareness.........................................1-6Use of Checklists......................................1-6Positive Transfer of Controls....................1-6

Chapter 2—Ground OperationsVisual Inspection ...........................................2-1

Inside the Cockpit.....................................2-2Outer Wing Surfacesand Tail Section .......................................2-4Fuel and Oil ..............................................2-5Landing Gear, Tires, and Brakes ..............2-6Engine and Propeller ................................2-6

Cockpit Management.....................................2-7Ground Operations ........................................2-7Engine Starting ..............................................2-7Hand Propping...............................................2-8Taxiing ...........................................................2-9Before Takeoff Check..................................2-11After Landing ..............................................2-11Clear of Runway..........................................2-11Parking.........................................................2-11Engine Shutdown.........................................2-12Postflight......................................................2-12Securing and Servicing................................2-12

Chapter 3—Basic Flight ManeuversThe Four Fundamentals.................................3-1Effects and Use of the Controls ....................3-1Feel of the Airplane .......................................3-2Attitude Flying...............................................3-2Integrated Flight Instruction..........................3-3Straight-and-Level Flight ..............................3-4Trim Control ..................................................3-6Level Turns....................................................3-7Climbs and Climbing Turns ........................3-13

Normal Climb.........................................3-13Best Rate of Climb .................................3-13Best Angle of Climb...............................3-13

Descents and Descending Turns..................3-15Partial Power Descent ............................3-16Descent at MinimumSafe Airspeed.........................................3-16

Glides......................................................3-16Pitch and Power...........................................3-19

Chapter 4—Slow Flight, Stalls, and SpinsIntroduction ...................................................4-1Slow Flight ....................................................4-1

Flight at Less thanCruise Airspeeds......................................4-1Flight at MinimumControllable Airspeed..............................4-1

Stalls ..............................................................4-3Recognition of Stalls ................................4-3Fundamentals of Stall Recovery ..............4-4Use of Ailerons/Rudderin Stall Recovery .....................................4-5Stall Characteristics ..................................4-6Approaches to Stalls (Imminent Stalls) —Power-On or Power-Off ......................4-6Full Stalls Power-Off................................4-7Full Stalls Power-On ................................4-8Secondary Stall .........................................4-9Accelerated Stalls .....................................4-9Cross-Control Stall .................................4-10Elevator Trim Stall .................................4-11

Spins ............................................................4-12Spin Procedures ......................................4-13

Entry Phase.........................................4-13Incipient Phase....................................4-13Developed Phase ................................4-14Recovery Phase ..................................4-14

Intentional Spins..........................................4-15Weight and Balance Requirements.........4-16

Chapter 5—Takeoff and Departure ClimbsGeneral...........................................................5-1Terms and Definitions ...................................5-1Prior to Takeoff..............................................5-2Normal Takeoff..............................................5-2

Takeoff Roll ..............................................5-2Lift-Off .....................................................5-3Initial Climb..............................................5-4

Crosswind Takeoff.........................................5-5Takeoff Roll ..............................................5-5Lift-Off .....................................................5-6Initial Climb..............................................5-6

Ground Effect on Takeoff..............................5-7Short-Field Takeoff and MaximumPerformance Climb.......................................5-8

Takeoff Roll ..............................................5-9Lift-Off .....................................................5-9Initial Climb..............................................5-9

Soft/Rough-Field Takeoff and Climb..........5-10

CONTENTS

Front Matter.qxd 5/7/04 10:45 AM Page v

vi

Takeoff Roll ............................................5-10Lift-Off ...................................................5-10Initial Climb............................................5-10

Rejected Takeoff/Engine Failure .................5-11Noise Abatement..........................................5-11

Chapter 6—Ground Reference ManeuversPurpose and Scope.........................................6-1Maneuvering By Referenceto Ground Objects ........................................6-1Drift and Ground Track Control....................6-2Rectangular Course .......................................6-4S-Turns Across a Road ..................................6-6Turns Around a Point ....................................6-7Elementary Eights .........................................6-9

Eights Along a Road.................................6-9Eights Across a Road..............................6-11Eights Around Pylons .............................6-11Eights-On-Pylons (Pylon Eights) ...........6-12

Chapter 7—Airport Traffic PatternsAirport Traffic Patterns and Operations ........7-1Standard Airport Traffic Patterns ..................7-1

Chapter 8—Approaches and LandingsNormal Approach and Landing .....................8-1

Base Leg ...................................................8-1Final Approach .........................................8-2Use of Flaps..............................................8-3Estimating Height and Movement............8-4Roundout (Flare) ......................................8-5Touchdown ...............................................8-6After-Landing Roll ...................................8-7Stabilized Approach Concept ...................8-7

Intentional Slips...........................................8-10Go-Arounds (Rejected Landings)................8-11

Power ......................................................8-11Attitude ...................................................8-12Configuration..........................................8-12

Ground Effect ..............................................8-13Crosswind Approach and Landing ..............8-13

Crosswind Final Approach .....................8-13Crosswind Roundout (Flare) ..................8-15Crosswind Touchdown ...........................8-15Crosswind After-Landing Roll ...............8-15Maximum SafeCrosswind Velocities .............................8-16

Turbulent Air Approach and Landing .........8-17Short-Field Approach and Landing .............8-17Soft-Field Approach and Landing ...............8-19Power-Off Accuracy Approaches ................8-21

90° Power-Off Approach........................8-21180° Power-Off Approach......................8-23

360° Power-Off Approach......................8-24Emergency Approaches andLandings (Simulated) .................................8-25Faulty Approaches and Landings ................8-27

Low Final Approach...............................8-27High Final Approach ..............................8-27Slow Final Approach ..............................8-28Use of Power ..........................................8-28High Roundout .......................................8-28Late or Rapid Roundout .........................8-29Floating During Roundout......................8-29Ballooning During Roundout .................8-30Bouncing During Touchdown ................8-30Porpoising...............................................8-31Wheelbarrowing .....................................8-32Hard Landing..........................................8-32Touchdown in a Drift or Crab ................8-32Ground Loop ..........................................8-33Wing Rising After Touchdown...............8-33

Hydroplaning ...............................................8-34Dynamic Hydroplaning ..........................8-34Reverted Rubber Hydroplaning..............8-34Viscous Hydroplaning ............................8-34

Chapter 9—Performance ManeuversPerformance Maneuvers................................9-1

Steep Turns ...............................................9-1Steep Spiral...............................................9-3Chandelle ..................................................9-4Lazy Eight ................................................9-6

Chapter 10—Night OperationsNight Vision.................................................10-1Night Illusions .............................................10-2Pilot Equipment ...........................................10-3Airplane Equipment and Lighting...............10-3Airport and Navigation Lighting Aids ........10-4Preparation and Preflight.............................10-4Starting, Taxiing, and Runup.......................10-5Takeoff and Climb.......................................10-5Orientation and Navigation .........................10-6Approaches and Landings ...........................10-6Night Emergencies ......................................10-8

Chapter 11—Transition to ComplexAirplanesHigh Performanceand Complex Airplanes ..............................11-1Wing Flaps...................................................11-1

Function of Flaps....................................11-1Flap Effectiveness...................................11-2Operational Procedures...........................11-2

Controllable-Pitch Propeller ........................11-3Constant-Speed Propeller .......................11-4

Front Matter.qxd 5/7/04 10:45 AM Page vi

vii

Takeoff, Climb, and Cruise ....................11-4Blade Angle Control ...............................11-5Governing Range....................................11-5Constant-Speed Propeller Operation ......11-5

Turbocharging..............................................11-7Ground Boosting vs.Altitude Turbocharging..........................11-7Operating Characteristics .......................11-8Heat Management...................................11-8Turbocharger Failure ..............................11-9

Overboost Condition...........................11-9Low Manifold Pressure ......................11-9

Retractable Landing Gear............................11-9Landing Gear Systems............................11-9Controls and Position Indicators ..........11-10Landing Gear Safety Devices...............11-10Emergency GearExtension Systems...............................11-10Operational Procedures.........................11-12

Preflight ............................................11-12Takeoff and Climb ............................11-13Approach and Landing .....................11-13

Transition Training ....................................11-14

Chapter 12—Transition to MultiengineAirplanesMultiengine Flight .......................................12-1General.........................................................12-1Terms and Definitions .................................12-1Operation of Systems ..................................12-3

Propellers ................................................12-3Propeller Synchronization ......................12-5Fuel Crossfeed ........................................12-5Combustion Heater.................................12-6Flight Director / Autopilot......................12-6Yaw Damper ...........................................12-6Alternator / Generator ............................12-7Nose Baggage Compartment..................12-7Anti-Icing / Deicing................................12-7

Performance and Limitations ......................12-8Weight and Balance...................................12-10Ground Operation......................................12-12Normal and CrosswindTakeoff and Climb....................................12-12Level Off and Cruise .................................12-14Normal Approach and Landing .................12-14Crosswind Approach and Landing ............12-16Short-Field Takeoff and Climb..................12-16Short-Field Approachand Landing ..............................................12-17Go-Around.................................................12-17Rejected Takeoff........................................12-18Engine Failure After Lift-Off ....................12-18Engine Failure During Flight ....................12-21

Engine Inoperative Approachand Landing ..............................................12-22Engine Inoperative Flight Principles.........12-23Slow Flight ................................................12-25Stalls ..........................................................12-25

Power-Off Stalls(Approach and Landing) .....................12-26Power-On Stalls(Takeoff and Departure) ......................12-26Spin Awareness.....................................12-26

Engine Inoperative—Loss ofDirectional Control Demonstration ..........12-27Multiengine Training Considerations........12-31

Chapter 13—Transition to TailwheelAirplanesTailwheel Airplanes .....................................13-1Landing Gear ...............................................13-1Taxiing .........................................................13-1Normal Takeoff Roll....................................13-2Takeoff.........................................................13-3Crosswind Takeoff.......................................13-3Short-Field Takeoff......................................13-3Soft-Field Takeoff........................................13-4Touchdown ..................................................13-4After-Landing Roll ......................................13-4Crosswind Landing......................................13-5Crosswind After-Landing Roll ....................13-5Wheel Landing ............................................13-6Short-Field Landing.....................................13-6Soft-Field Landing.......................................13-6Ground Loop ...............................................13-6

Chapter 14—Transition to TurbopropellerPowered AirplanesGeneral.........................................................14-1The Gas Turbine Engine..............................14-1Turboprop Engines ......................................14-2Turboprop Engine Types .............................14-3

Fixed Shaft..............................................14-3Split-Shaft / Free Turbine Engine ..........14-5

Reverse Thrust andBeta Range Operations...............................14-7Turboprop AirplaneElectrical Systems ......................................14-8Operational Considerations .......................14-10Training Considerations ............................14-12

Chapter 15—Transition to Jet PoweredAirplanesGeneral.........................................................15-1Jet Engine Basics.........................................15-1Operating the Jet Engine .............................15-2

Jet Engine Ignition..................................15-3Continuous Ignition ................................15-3

Front Matter.qxd 5/7/04 10:45 AM Page vii

viii

Fuel Heaters............................................15-3Setting Power..........................................15-4Thrust to Thrust Lever Relationship ......15-4Variation of Thrust with RPM................15-4Slow Acceleration of the Jet Engine ......15-4

Jet Engine Efficiency...................................15-5Absence of Propeller Effect ........................15-5Absence of Propeller Slipstream .................15-5Absence of Propeller Drag ..........................15-6Speed Margins .............................................15-6Recovery from Overspeed Conditions ........15-8Mach Buffet Boundaries..............................15-8Low Speed Flight ......................................15-10Stalls ..........................................................15-10Drag Devices .............................................15-13Thrust Reversers........................................15-14Pilot Sensations in Jet Flying ....................15-15Jet Airplane Takeoff and Climb.................15-16

V-Speeds ...............................................15-16Pre-Takeoff Procedures ........................15-16Takeoff Roll ..........................................15-17Rotation and Lift-Off............................15-18Initial Climb..........................................15-18

Jet Airplane Approach and Landing..........15-19Landing Requirements..........................15-19Landing Speeds ....................................15-19Significant Differences .........................15-20The Stabilized Approach ......................15-21Approach Speed....................................15-21Glidepath Control .................................15-22The Flare...............................................15-22Touchdown and Rollout .......................15-24

Chapter 16—Emergency ProceduresEmergency Situations ..................................16-1Emergency Landings ...................................16-1

Types of Emergency Landings ...............16-1Psychological Hazards............................16-1

Basic Safety Concepts .................................16-2

General....................................................16-2Attitude and Sink Rate Control ..............16-3Terrain Selection.....................................16-3Airplane Configuration...........................16-3Approach ................................................16-4

Terrain Types ...............................................16-4Confined Areas .......................................16-4Trees (Forest)..........................................16-4Water (Ditching) and Snow....................16-4

Engine Failure After Takeoff(Single-Engine)...........................................16-5Emergency Descents ...................................16-6In-Flight Fire ...............................................16-7

Engine Fire .............................................16-7Electrical Fires........................................16-7Cabin Fire ...............................................16-8

Flight Control Malfunction / Failure...........16-8Total Flap Failure ...................................16-8Asymmetric (Split) Flap.........................16-8Loss of Elevator Control ........................16-9

Landing Gear Malfunction ..........................16-9Systems Malfunctions ...............................16-10

Electrical System..................................16-10Pitot-Static System ...............................16-11

Abnormal EngineInstrument Indications ..............................16-11Door Opening In Flight .............................16-12Inadvertent VFR Flight Into IMC .............16-12

General..................................................16-12Recognition...........................................16-14Maintaining Airplane Control ..............16-14Attitude Control....................................16-14Turns .....................................................16-15Climbs...................................................16-15Descents................................................16-16Combined Maneuvers...........................16-16Transition to Visual Flight....................16-16

Glossary .......................................................G-1

Index ..............................................................I-1

Front Matter.qxd 5/7/04 10:45 AM Page viii

PURPOSE OF FLIGHT TRAININGThe overall purpose of primary and intermediate flighttraining, as outlined in this handbook, is the acquisitionand honing of basic airmanship skills. Airmanshipcan be defined as:

• A sound acquaintance with the principles offlight,

• The ability to operate an airplane with compe-tence and precision both on the ground and in theair, and

• The exercise of sound judgment that results inoptimal operational safety and efficiency.

Learning to fly an airplane has often been likened tolearning to drive an automobile. This analogy ismisleading. Since an airplane operates in a differentenvironment, three dimensional, it requires a type ofmotor skill development that is more sensitive to thissituation such as:

• Coordination—The ability to use the hands andfeet together subconsciously and in the properrelationship to produce desired results in the air-plane.

• Timing—The application of muscular coordina-tion at the proper instant to make flight, and allmaneuvers incident thereto, a constant smoothprocess.

• Control touch—The ability to sense the actionof the airplane and its probable actions in theimmediate future, with regard to attitude andspeed variations, by the sensing and evaluation ofvarying pressures and resistance of the controlsurfaces transmitted through the cockpit flightcontrols.

• Speed sense—The ability to sense instantly andreact to any reasonable variation of airspeed.

An airman becomes one with the airplane rather thana machine operator. An accomplished airmandemonstrates the ability to assess a situation quicklyand accurately and deduce the correct procedure tobe followed under the circumstance; to analyzeaccurately the probable results of a given set of cir-cumstances or of a proposed procedure; to exercisecare and due regard for safety; to gauge accuratelythe performance of the airplane; and to recognize

personal limitations and limitations of the airplaneand avoid approaching the critical points of each.The development of airmanship skills requires effortand dedication on the part of both the student pilotand the flight instructor, beginning with the very firsttraining flight where proper habit formation beginswith the student being introduced to good operatingpractices.

Every airplane has its own particular flight characteris-tics. The purpose of primary and intermediate flighttraining, however, is not to learn how to fly a particularmake and model airplane. The underlying purpose offlight training is to develop skills and safe habits thatare transferable to any airplane. Basic airmanship skillsserve as a firm foundation for this. The pilot who hasacquired necessary airmanship skills during training,and demonstrates these skills by flying training-typeairplanes with precision and safe flying habits, will beable to easily transition to more complex and higherperformance airplanes. It should also be rememberedthat the goal of flight training is a safe and competentpilot, and that passing required practical tests for pilotcertification is only incidental to this goal.

ROLE OF THE FAAThe Federal Aviation Administration (FAA) is empow-ered by the U.S. Congress to promote aviation safetyby prescribing safety standards for civil aviation. Thisis accomplished through the Code of FederalRegulations (CFRs) formerly referred to as FederalAviation Regulations (FARs).

Title 14 of the Code of Federal Regulations (14 CFR)part 61 pertains to the certification of pilots, flightinstructors, and ground instructors. 14 CFR part 61 pre-scribes the eligibility, aeronautical knowledge, flightproficiency, and training and testing requirements foreach type of pilot certificate issued.

14 CFR part 67 prescribes the medical standards andcertification procedures for issuing medical certificatesfor airmen and for remaining eligible for a medicalcertificate.

14 CFR part 91 contains general operating and flightrules. The section is broad in scope and providesgeneral guidance in the areas of general flight rules,visual flight rules (VFR), instrument flight rules(IFR), aircraft maintenance, and preventive mainte-nance and alterations.

1-1

Ch 01.qxd 5/6/04 11:25 AM Page 1-1

1-2

Within the FAA, the Flight Standards Service sets theaviation standards for airmen and aircraft operations inthe United States and for American airmen and aircraftaround the world. The FAA Flight Standards Service isheadquartered in Washington, D.C., and is broadlyorganized into divisions based on work function (AirTransportation, Aircraft Maintenance, TechnicalPrograms, a Regulatory Support Division based inOklahoma City, OK, and a General Aviation andCommercial Division). Regional Flight Standards divi-sion managers, one at each of the FAA’s nine regionaloffices, coordinate Flight Standards activities withintheir respective regions.

The interface between the FAA Flight StandardsService and the aviation community/general publicis the local Flight Standards District Office (FSDO).[Figure 1-1] The approximately 90 FSDOs arestrategically located across the United States, eachoffice having jurisdiction over a specific geographicarea. The individual FSDO is responsible for all airactivity occurring within its geographic boundaries.In addition to accident investigation and theenforcement of aviation regulations, the individualFSDO is responsible for the certification and sur-veillance of air carriers, air operators, flightschools/training centers, and airmen including pilotsand flight instructors.

Each FSDO is staffed by aviation safety inspectorswhose specialties include operations, maintenance,and avionics. General aviation operations inspec-tors are highly qualified and experienced aviators.Once accepted for the position, an inspector mustsatisfactorily complete a course of indoctrinationtraining conducted at the FAA Academy, whichincludes airman evaluation and pilot testing tech-niques and procedures. Thereafter, the inspector mustcomplete recurrent training on a regular basis. Amongother duties, the FSDO inspector is responsible foradministering FAA practical tests for pilot and flight

instructor certificates and associated ratings. All ques-tions concerning pilot certification (and/or requests forother aviation information or services) should be directedto the FSDO having jurisdiction in the particular geo-graphic area. FSDO telephone numbers are listed in theblue pages of the telephone directory under United StatesGovernment offices, Department of Transportation,Federal Aviation Administration.

ROLE OF THE PILOT EXAMINERPilot and flight instructor certificates are issued bythe FAA upon satisfactory completion of requiredknowledge and practical tests. The administrationof these tests is an FAA responsibility normallycarried out at the FSDO level by FSDO inspectors.The FAA, however, being a U.S. governmentagency, has limited resources and must prioritizeits responsibilities. The agency’s highest priorityis the surveillance of certificated air carriers, withthe certification of airmen (including pilots andflight instructors) having a lower priority.

In order to satisfy the public need for pilot testing andcertification services, the FAA delegates certain of theseresponsibilities, as the need arises, to private individu-als who are not FAA employees. A designated pilotexaminer (DPE) is a private citizen who is designatedas a representative of the FAAAdministrator to performspecific (but limited) pilot certification tasks on behalfof the FAA, and may charge a reasonable fee for doingso. Generally, a DPE’s authority is limited to acceptingapplications and conducting practical tests leading tothe issuance of specific pilot certificates and/or ratings.A DPE operates under the direct supervision of theFSDO that holds the examiner’s designation file. AFSDO inspector is assigned to monitor the DPE’s certi-fication activities. Normally, the DPE is authorized toconduct these activities only within the designatingFSDO’s jurisdictional area.

The FAA selects only highly qualified individuals tobe designated pilot examiners. These individuals musthave good industry reputations for professionalism,high integrity, a demonstrated willingness to serve thepublic, and adhere to FAA policies and procedures incertification matters. A designated pilot examiner isexpected to administer practical tests with the samedegree of professionalism, using the same methods,procedures, and standards as an FAA aviation safetyinspector. It should be remembered, however, that aDPE is not an FAA aviation safety inspector. A DPEcannot initiate enforcement action, investigate acci-dents, or perform surveillance activities on behalf ofthe FAA. However, the majority of FAA practical testsat the recreational, private, and commercial pilot levelare administered by FAA designated pilot examiners.Figure 1-1. FAA FSDO.

Ch 01.qxd 5/6/04 11:25 AM Page 1-2

1-3

ROLE OF THE FLIGHT INSTRUCTORThe flight instructor is the cornerstone of aviationsafety. The FAA has adopted an operational trainingconcept that places the full responsibility for studenttraining on the authorized flight instructor. In this role,the instructor assumes the total responsibility for train-ing the student pilot in all the knowledge areas andskills necessary to operate safely and competently as acertificated pilot in the National Airspace System. Thistraining will include airmanship skills, pilot judgmentand decision making, and accepted good operatingpractices.

An FAA certificated flight instructor has to meetbroad flying experience requirements, pass rigidknowledge and practical tests, and demonstrate theability to apply recommended teaching techniquesbefore being certificated. In addition, the flightinstructor’s certificate must be renewed every 24months by showing continued success in trainingpilots, or by satisfactorily completing a flight instruc-tor’s refresher course or a practical test designed toupgrade aeronautical knowledge, pilot proficiency,and teaching techniques.

A pilot training program is dependent on the quality ofthe ground and flight instruction the student pilotreceives. A good flight instructor will have a thoroughunderstanding of the learning process, knowledge ofthe fundamentals of teaching, and the ability to com-municate effectively with the student pilot.

A good flight instructor will use a syllabus and insiston correct techniques and procedures from thebeginning of training so that the student will developproper habit patterns. The syllabus should embodythe “building block” method of instruction, in whichthe student progresses from the known to theunknown. The course of instruction should be laidout so that each new maneuver embodies the principlesinvolved in the performance of those previouslyundertaken. Consequently, through each new subjectintroduced, the student not only learns a new princi-ple or technique, but broadens his/her application ofthose previously learned and has his/her deficienciesin the previous maneuvers emphasized and madeobvious.

The flying habits of the flight instructor, both duringflight instruction and as observed by students whenconducting other pilot operations, have a vital effecton safety. Students consider their flight instructor to bea paragon of flying proficiency whose flying habitsthey, consciously or unconsciously, attempt to imitate.For this reason, a good flight instructor will meticu-lously observe the safety practices taught the students.Additionally, a good flight instructor will carefully

observe all regulations and recognized safety practicesduring all flight operations.

Generally, the student pilot who enrolls in a pilot trainingprogram is prepared to commit considerable time,effort, and expense in pursuit of a pilot certificate. Thestudent may tend to judge the effectiveness of the flightinstructor, and the overall success of the pilot trainingprogram, solely in terms of being able to pass therequisite FAA practical test. A good flight instructor,however, will be able to communicate to the studentthat evaluation through practical tests is a mere sam-pling of pilot ability that is compressed into a shortperiod of time. The flight instructor’s role, however, isto train the “total” pilot.

SOURCES OF FLIGHT TRAININGThe major sources of flight training in the United Statesinclude FAA-approved pilot schools and training cen-ters, non-certificated (14 CFR part 61) flying schools,and independent flight instructors. FAA “approved”schools are those flight schools certificated by the FAAas pilot schools under 14 CFR part 141. [Figure 1-2]Application for certification is voluntary, and the schoolmust meet stringent requirements for personnel, equip-ment, maintenance, and facilities. The school mustoperate in accordance with an established curriculum,which includes a training course outline (TCO)

Figure 1-2. FAA-approved pilot school certificate.

Ch 01.qxd 5/6/04 11:25 AM Page 1-3

1-4

approved by the FAA. The TCO must contain studentenrollment prerequisites, detailed description of eachlesson including standards and objectives, expectedaccomplishments and standards for each stage of train-ing, and a description of the checks and tests used tomeasure a student’s accomplishments. FAA-approvedpilot school certificates must be renewed every 2 years.Renewal is contingent upon proof of continued highquality instruction and a minimum level of instructionalactivity. Training at an FAA certificated pilot school isstructured. Because of this structured environment, theCFRs allow graduates of these pilot schools to meet thecertification experience requirements of 14 CFR part61 with less flight time. Many FAA certificated pilotschools have designated pilot examiners (DPEs) ontheir staff to administer FAA practical tests. Someschools have been granted examining authority by theFAA. A school with examining authority for a particu-lar course or courses has the authority to recommend itsgraduates for pilot certificates or ratings without furthertesting by the FAA. A list of FAA certificated pilotschools and their training courses can be found inAdvisory Circular (AC) 140-2, FAA Certificated PilotSchool Directory.

FAA-approved training centers are certificated under14 CFR part 142. Training centers, like certificatedpilot schools, operate in a structured environment withapproved courses and curricula, and stringent standardsfor personnel, equipment, facilities, operating proce-dures and record keeping. Training centers certificatedunder 14 CFR part 142, however, specialize in the useof flight simulation (flight simulators and flight train-ing devices) in their training courses.

The overwhelming majority of flying schools in theUnited States are not certificated by the FAA. Theseschools operate under the provisions of 14 CFR part61. Many of these non-certificated flying schools offerexcellent training, and meet or exceed the standardsrequired of FAA-approved pilot schools. Flightinstructors employed by non-certificated flyingschools, as well as independent flight instructors, mustmeet the same basic 14 CFR part 61 flight instructorrequirements for certification and renewal as thoseflight instructors employed by FAA certificated pilotschools. In the end, any training program is dependentupon the quality of the ground and flight instruction astudent pilot receives.

PRACTICAL TEST STANDARDSPractical tests for FAA pilot certificates and associatedratings are administered by FAA inspectors and desig-nated pilot examiners in accordance with FAA-developedpractical test standards (PTS). [Figure 1-3] 14 CFRpart 61 specifies the areas of operation in whichknowledge and skill must be demonstrated by theapplicant. The CFRs provide the flexibility to permit

the FAA to publish practical test standards containingthe areas of operation and specific tasks in whichcompetence must be demonstrated. The FAA requiresthat all practical tests be conducted in accordance withthe appropriate practical test standards and the policiesset forth in the Introduction section of the practical teststandard book.

It must be emphasized that the practical test standardsbook is a testing document rather than a teaching doc-ument. An appropriately rated flight instructor isresponsible for training a pilot applicant to acceptablestandards in all subject matter areas, procedures, andmaneuvers included in the tasks within each area ofoperation in the appropriate practical test standard.The pilot applicant should be familiar with this bookand refer to the standards it contains during training.However, the practical test standard book is notintended to be used as a training syllabus. It containsthe standards to which maneuvers/procedures on FAApractical tests must be performed and the FAA policiesgoverning the administration of practical tests.Descriptions of tasks, and information on how toperform maneuvers and procedures are contained inreference and teaching documents such as thishandbook. A list of reference documents is containedin the Introduction section of each practical test stan-dard book.

Practical test standards may be downloaded from theRegulatory Support Division’s, AFS-600, Web site athttp://afs600.faa.gov. Printed copies of practical teststandards can be purchased from the Superintendentof Documents, U.S. Government Printing Office,Washington, DC 20402. The official online bookstoreWeb site for the U.S. Government Printing Office iswww.access.gpo.gov.

FLIGHT SAFETY PRACTICESIn the interest of safety and good habit pattern forma-tion, there are certain basic flight safety practices andprocedures that must be emphasized by the flightinstructor, and adhered to by both instructor and student,beginning with the very first dual instruction flight.These include, but are not limited to, collisionavoidance procedures including proper scanningtechniques and clearing procedures, runway incursionavoidance, stall awareness, positive transfer ofcontrols, and cockpit workload management.

COLLISION AVOIDANCEAll pilots must be alert to the potential for midaircollision and near midair collisions. The general operat-ing and flight rules in 14 CFR part 91 set forth theconcept of “See and Avoid.” This concept requiresthat vigilance shall be maintained at all times, byeach person operating an aircraft regardless ofwhether the operation is conducted under instrument

Ch 01.qxd 5/6/04 11:25 AM Page 1-4

1-5

flight rules (IFR) or visual flight rules (VFR). Pilotsshould also keep in mind their responsibility for con-tinuously maintaining a vigilant lookout regardless ofthe type of aircraft being flown and the purpose of theflight. Most midair collision accidents and reportednear midair collision incidents occur in good VFRweather conditions and during the hours of daylight.Most of these accident/incidents occur within 5 milesof an airport and/or near navigation aids.

The “See and Avoid” concept relies on knowledgeof the limitations of the human eye, and the use ofproper visual scanning techniques to help compen-sate for these limitations. The importance of, andthe proper techniques for, visual scanning shouldbe taught to a student pilot at the very beginning offlight training. The competent flight instructorshould be familiar with the visual scanning andcollision avoidance information contained inAdvisory Circular (AC) 90-48, Pilots’ Role inCollision Avoidance, and the AeronauticalInformation Manual (AIM).

There are many different types of clearing procedures.Most are centered around the use of clearing turns. Theessential idea of the clearing turn is to be certain thatthe next maneuver is not going to proceed into anotherairplane’s flightpath. Some pilot training programshave hard and fast rules, such as requiring two 90°

turns in opposite directions before executing anytraining maneuver. Other types of clearing proceduresmay be developed by individual flight instructors.Whatever the preferred method, the flight instructorshould teach the beginning student an effective clear-ing procedure and insist on its use. The student pilotshould execute the appropriate clearing procedurebefore all turns and before executing any trainingmaneuver. Proper clearing procedures, combinedwith proper visual scanning techniques, are the mosteffective strategy for collision avoidance.

RUNWAY INCURSION AVOIDANCEA runway incursion is any occurrence at an airportinvolving an aircraft, vehicle, person, or object on theground that creates a collision hazard or results in aloss of separation with an aircraft taking off, landing,or intending to land. The three major areas contribut-ing to runway incursions are:

• Communications,

• Airport knowledge, and

• Cockpit procedures for maintaining orientation.

Taxi operations require constant vigilance by the entireflight crew, not just the pilot taxiing the airplane. Thisis especially true during flight training operations.Both the student pilot and the flight instructor need tobe continually aware of the movement and location of

Figure 1-3. PTS books.

Ch 01.qxd 5/6/04 11:25 AM Page 1-5

1-6

other aircraft and ground vehicles on the airportmovement area. Many flight training activities areconducted at non-tower controlled airports. Theabsence of an operating airport control tower creates aneed for increased vigilance on the part of pilots oper-ating at those airports.

Planning, clear communications, and enhancedsituational awareness during airport surfaceoperations will reduce the potential for surface inci-dents. Safe aircraft operations can be accomplishedand incidents eliminated if the pilot is properly trainedearly on and, throughout his/her flying career,accomplishes standard taxi operating procedures andpractices. This requires the development of theformalized teaching of safe operating practices duringtaxi operations. The flight instructor is the key to thisteaching. The flight instructor should instill in thestudent an awareness of the potential for runwayincursion, and should emphasize the runwayincursion avoidance procedures contained inAdvisory Circular (AC) 91-73, Part 91 Pilot andFlightcrew Procedures During Taxi Operations andPart 135 Single-Pilot Operations.

STALL AWARENESS14 CFR part 61 requires that a student pilot receive andlog flight training in stalls and stall recoveries prior tosolo flight. During this training, the flight instructorshould emphasize that the direct cause of every stall isan excessive angle of attack. The student pilot shouldfully understand that there are any number of flightmaneuvers which may produce an increase in thewing’s angle of attack, but the stall does not occur untilthe angle of attack becomes excessive. This “critical”angle of attack varies from 16 to 20° depending on theairplane design.

The flight instructor must emphasize that low speed isnot necessary to produce a stall. The wing can bebrought to an excessive angle of attack at any speed.High pitch attitude is not an absolute indication ofproximity to a stall. Some airplanes are capable of ver-tical flight with a corresponding low angle of attack.Most airplanes are quite capable of stalling at a level ornear level pitch attitude.

The key to stall awareness is the pilot’s ability tovisualize the wing’s angle of attack in any particularcircumstance, and thereby be able to estimate his/hermargin of safety above stall. This is a learned skillthat must be acquired early in flight training andcarried through the pilot’s entire flying career. Thepilot must understand and appreciate factors such asairspeed, pitch attitude, load factor, relative wind,power setting, and aircraft configuration in order todevelop a reasonably accurate mental picture of thewing’s angle of attack at any particular time. It is

essential to flight safety that a pilot take into consid-eration this visualization of the wing’s angle ofattack prior to entering any flight maneuver.

USE OF CHECKLISTSChecklists have been the foundation of pilot standard-ization and cockpit safety for years. The checklist is anaid to the memory and helps to ensure that criticalitems necessary for the safe operation of aircraft arenot overlooked or forgotten. However, checklists areof no value if the pilot is not committed to its use.Without discipline and dedication to using the check-list at the appropriate times, the odds are on the side oferror. Pilots who fail to take the checklist seriouslybecome complacent and the only thing they can relyon is memory.

The importance of consistent use of checklists cannotbe overstated in pilot training. A major objective inprimary flight training is to establish habit patterns thatwill serve pilots well throughout their entire flyingcareer. The flight instructor must promote a positiveattitude toward the use of checklists, and the studentpilot must realize its importance. At a minimum, pre-pared checklists should be used for the followingphases of flight.

• Preflight Inspection.

• Before Engine Start.

• Engine Starting.

• Before Taxiing.

• Before Takeoff.

• After Takeoff.

• Cruise.

• Descent.

• Before Landing.

• After Landing.

• Engine Shutdown and Securing.

POSITIVE TRANSFER OF CONTROLSDuring flight training, there must always be a clearunderstanding between the student and flight instruc-tor of who has control of the aircraft. Prior to anydual training flight, a briefing should be conductedthat includes the procedure for the exchange of flightcontrols. The following three-step process for theexchange of flight controls is highly recommended.

When a flight instructor wishes the student to takecontrol of the aircraft, he/she should say to the stu-dent, “You have the flight controls.” The studentshould acknowledge immediately by saying, “I havethe flight controls.” The flight instructor confirms by

Ch 01.qxd 5/6/04 11:25 AM Page 1-6

1-7

again saying, “You have the flight controls.” Part ofthe procedure should be a visual check to ensure thatthe other person actually has the flight controls. Whenreturning the controls to the flight instructor, the stu-dent should follow the same procedure the instructorused when giving control to the student. The studentshould stay on the controls until the instructor says:“I have the flight controls.” There should never be

any doubt as to who is flying the airplane at any onetime. Numerous accidents have occurred due to a lackof communication or misunderstanding as to whoactually had control of the aircraft, particularlybetween students and flight instructors. Establishingthe above procedure during initial training will ensurethe formation of a very beneficial habit pattern.

Ch 01.qxd 5/6/04 11:25 AM Page 1-7

1-8

Ch 01.qxd 5/6/04 11:25 AM Page 1-8

2-1

VISUAL INSPECTIONThe accomplishment of a safe flight begins with a care-ful visual inspection of the airplane. The purpose of thepreflight visual inspection is twofold: to determine thatthe airplane is legally airworthy, and that it is in condi-tion for safe flight. The airworthiness of the airplane isdetermined, in part, by the following certificates anddocuments, which must be on board the airplane whenoperated. [Figure 2-1]

Airworthiness certificate.

Registration certificate.

FCC radio station license, if required by the typeof operation.

Airplane operating limitations, which may be inthe form of an FAA-approved Airplane FlightManual and/or Pilot’s Operating Handbook(AFM/POH), placards, instrument markings, orany combination thereof.

Airplane logbooks are not required to be kept in theairplane when it is operated. However, they should beinspected prior to flight to show that the airplane hashad required tests and inspections. Maintenance

records for the airframe and engine are required to bekept. There may also be additional propeller records.

At a minimum, there should be an annual inspectionwithin the preceding 12-calendar months. In addition,the airplane may also be required to have a 100-hourinspection in accordance with Title14 of the Code ofFederal Regulations (14 CFR) part 91, section91.409(b).

If a transponder is to be used, it is required to beinspected within the preceding 24-calendar months. Ifthe airplane is operated under instrument flight rules(IFR) in controlled airspace, the pitot-static system isalso required to be inspected within the preceding24-calendar months.

The emergency locator transmitter (ELT) should alsobe checked. The ELT is battery powered, and thebattery replacement or recharge date should notbe exceeded.

Airworthiness Directives (ADs) have varyingcompliance intervals and are usually tracked in aseparate area of the appropriate airframe, engine, orpropeller record.

Figure 2-1. Aircraft documents and AFM/POH.

•

•

•

•

Ch 02.qxd 5/7/04 6:22 AM Page 2-1

2-2

The determination of whether the airplane is in a con-dition for safe flight is made by a preflight inspectionof the airplane and its components. [Figure 2-2] Thepreflight inspection should be performed in accordancewith a printed checklist provided by the airplane man-ufacturer for the specific make and model airplane.However, the following general areas are applicable toall airplanes.

The preflight inspection of the airplane should beginwhile approaching the airplane on the ramp. The pilotshould make note of the general appearance of theairplane, looking for obvious discrepancies such as alanding gear out of alignment, structural distortion,skin damage, and dripping fuel or oil leaks. Uponreaching the airplane, all tiedowns, control locks, andchocks should be removed.

INSIDE THE COCKPITThe inspection should start with the cabin door. If thedoor is hard to open or close, or if the carpeting orseats are wet from a recent rain, there is a good chancethat the door, fuselage, or both are misaligned. Thismay be a sign of structural damage.

The windshield and side windows should be examinedfor cracks and/or crazing. Crazing is the first stage ofdelamination of the plastic. Crazing decreasesvisibility, and a severely crazed window can result innear zero visibility due to light refraction at certainangles to the sun.

The pilot should check the seats, seat rails, and seatbelt attach points for wear, cracks, and serviceability.The seat rail holes where the seat lock pins fit should

1

2

3

4

5

67

8

910

Figure 2-2. Preflight inspection.

Figure 2-3. Inside the cockpit.

Ch 02.qxd 5/7/04 6:22 AM Page 2-2

2-3

also be inspected. The holes should be round and notoval. The pin and seat rail grips should also be checkedfor wear and serviceability.

Inside the cockpit, three key items to be checked are:(1) battery and ignition switches—off, (2) controlcolumn locks—removed, (3) landing gear control—down and locked. [Figure 2-3]

The fuel selectors should be checked for properoperation in all positions—including the OFF posi-tion. Stiff selectors, or ones where the tank position ishard to find, are unacceptable. The primer should alsobe exercised. The pilot should feel resistance whenthe primer is both pulled out and pushed in. Theprimer should also lock securely. Faulty primers caninterfere with proper engine operation. [Figure 2-4]The engine controls should also be manipulated byslowly moving each through its full range to checkfor binding or stiffness.

The airspeed indicator should be properly marked, andthe indicator needle should read zero. If it does not, theinstrument may not be calibrated correctly. Similarly,the vertical speed indicator (VSI) should also read zerowhen the airplane is on the ground. If it does not, asmall screwdriver can be used to zero the instrument.The VSI is the only flight instrument that a pilot hasthe prerogative to adjust. All others must be adjustedby an FAA certificated repairman or mechanic.

The magnetic compass is a required instrument forboth VFR and IFR flight. It must be securely mounted,with a correction card in place. The instrument facemust be clear and the instrument case full of fluid. Acloudy instrument face, bubbles in the fluid, or apartially filled case renders the instrument unusable.[Figure 2-5]

The gyro driven attitude indicator should be checkedbefore being powered. A white haze on the inside of

Figure 2-4. Fuel selector and primer.

Figure 2-5. Airspeed indicator, VSI, and magnetic compass.

Ch 02.qxd 5/7/04 6:22 AM Page 2-3

2-4

the glass face may be a sign that the seal has beenbreached, allowing moisture and dirt to be sucked intothe instrument.

The altimeter should be checked against the ramp orfield elevation after setting in the barometric pressure.If the variation between the known field elevation andthe altimeter indication is more than 75 feet, itsaccuracy is questionable.

The pilot should turn on the battery master switch andmake note of the fuel quantity gauge indications forcomparison with an actual visual inspection of the fueltanks during the exterior inspection.

OUTER WING SURFACES AND TAILSECTIONThe pilot should inspect for any signs of deterioration,distortion, and loose or missing rivets or screws,especially in the area where the outer skin attaches tothe airplane structure. [Figure 2-6] The pilot shouldlook along the wing spar rivet line—from the wingtipto the fuselage—for skin distortion. Any ripples and/orwaves may be an indication of internal damageor failure.

Loose or sheared aluminum rivets may be identified bythe presence of black oxide which forms rapidly when

the rivet works free in its hole. Pressure applied to theskin adjacent to the rivet head will help verify theloosened condition of the rivet.

When examining the outer wing surface, it should beremembered that any damage, distortion, ormalformation of the wing leading edge renders theairplane unairworthy. Serious dents in the leadingedge, and disrepair of items such as stall strips, anddeicer boots can cause the airplane to beaerodynamically unsound. Also, special care shouldbe taken when examining the wingtips. Airplanewingtips are usually fiberglass. They are easilydamaged and subject to cracking. The pilot shouldlook at stop drilled cracks for evidence of crackprogression, which can, under some circumstances,lead to in-flight failure of the wingtip.

The pilot should remember that fuel stains anywhereon the wing warrant further investigation—no matterhow old the stains appear to be. Fuel stains are a signof probable fuel leakage. On airplanes equipped withintegral fuel tanks, evidence of fuel leakage can befound along rivet lines along the underside ofthe wing.

Figure 2-6. Wing and tail section inspection.

Ch 02.qxd 5/7/04 6:22 AM Page 2-4

2-5

FUEL AND OILParticular attention should be paid to the fuel quantity,type and grade, and quality. [Figure 2-7] Many fueltanks are very sensitive to airplane attitude whenattempting to fuel for maximum capacity. Nosewheelstrut extension, both high as well as low, cansignificantly alter the attitude, and therefore the fuelcapacity. The airplane attitude can also be affectedlaterally by a ramp that slopes, leaving one wingslightly higher than another. Always confirm the fuelquantity indicated on the fuel gauges by visuallyinspecting the level of each tank.

The type, grade, and color of fuel are critical to safeoperation. The only widely available aviation gasoline(AVGAS) grade in the United States is low-lead100-octane, or 100LL. AVGAS is dyed for easyrecognition of its grade and has a familiar gasolinescent. Jet-A, or jet fuel, is a kerosene-based fuel forturbine powered airplanes. It has disastrousconsequences when inadvertently introduced intoreciprocating airplane engines. The piston engineoperating on jet fuel may start, run, and power theairplane, but will fail because the engine has beendestroyed from detonation.

Jet fuel has a distinctive kerosene scent and is oily tothe touch when rubbed between fingers. Jet fuel isclear or straw colored, although it may appear dyedwhen mixed in a tank containing AVGAS. When a fewdrops of AVGAS are placed upon white paper, theyevaporate quickly and leave just a trace of dye. Incomparison, jet fuel is slower to evaporate and leavesan oily smudge. Jet fuel refueling trucks anddispensing equipment are marked with JET-A placardsin white letters on a black background. Prudent pilotswill supervise fueling to ensure that the correct tanksare filled with the right quantity, type, and grade of

fuel. The pilot should always ensure that the fuel capshave been securely replaced following each fueling.

Engines certificated for grades 80/87 or 91/96 AVGASwill run satisfactorily on 100LL. The reverse is nottrue. Fuel of a lower grade/octane, if found, shouldnever be substituted for a required higher grade.Detonation will severely damage the engine in a veryshort period of time.

Automotive gasoline is sometimes used as a substitutefuel in certain airplanes. Its use is acceptable onlywhen the particular airplane has been issued asupplemental type certificate (STC) to both theairframe and engine allowing its use.

Checking for water and other sediment contaminationis a key preflight element. Water tends to accumulatein fuel tanks from condensation, particularly inpartially filled tanks. Because water is heavier thanfuel, it tends to collect in the low points of the fuelsystem. Water can also be introduced into the fuelsystem from deteriorated gas cap seals exposed to rain,or from the supplier’s storage tanks and deliveryvehicles. Sediment contamination can arise from dustand dirt entering the tanks during refueling, or fromdeteriorating rubber fuel tanks or tank sealant.

The best preventive measure is to minimize theopportunity for water to condense in the tanks. Ifpossible, the fuel tanks should be completely filledwith the proper grade of fuel after each flight, or atleast filled after the last flight of the day. The more fuelthere is in the tanks, the less opportunity forcondensation to occur. Keeping fuel tanks filled is alsothe best way to slow the aging of rubber fuel tanks andtank sealant.

Sufficient fuel should be drained from the fuel strainerquick drain and from each fuel tank sump to check forfuel grade/color, water, dirt, and smell. If water ispresent, it will usually be in bead-like droplets,different in color (usually clear, sometimes muddy), inthe bottom of the sample. In extreme cases, do notoverlook the possibility that the entire sample,particularly a small sample, is water. If water is foundin the first fuel sample, further samples should be takenuntil no water appears. Significant and/or consistentwater or sediment contamination are grounds forfurther investigation by qualified maintenancepersonnel. Each fuel tank sump should be drainedduring preflight and after refueling.

The fuel tank vent is an important part of a preflightinspection. Unless outside air is able to enter the tankas fuel is drawn out, the eventual result will be fuelgauge malfunction and/or fuel starvation. During thepreflight inspection, the pilot should be alert for any

Figure 2-7. Aviation fuel types, grades, and colors.

Ch 02.qxd 5/7/04 6:22 AM Page 2-5

2-6

signs of vent tubing damage, as well as vent blockage.A functional check of the fuel vent system can be donesimply by opening the fuel cap. If there is a rush of airwhen the fuel tank cap is cracked, there could be aserious problem with the vent system.

The oil level should be checked during each preflightand rechecked with each refueling. Reciprocatingairplane engines can be expected to consume a smallamount of oil during normal operation. If theconsumption grows or suddenly changes, qualifiedmaintenance personnel should investigate. If lineservice personnel add oil to the engine, the pilot shouldensure that the oil cap has been securely replaced.

LANDING GEAR,TIRES, AND BRAKESTires should be inspected for proper inflation, as wellas cuts, bruises, wear, bulges, imbedded foreign object,and deterioration. As a general rule, tires with cordshowing, and those with cracked sidewalls areconsidered unairworthy.

Brakes and brake systems should be checked for rustand corrosion, loose nuts/bolts, alignment, brake padwear/cracks, signs of hydraulic fluid leakage, andhydraulic line security/abrasion.

An examination of the nose gear should include theshimmy damper, which is painted white, and the torquelink, which is painted red, for proper servicing andgeneral condition. All landing gear shock struts shouldalso be checked for proper inflation.

ENGINE AND PROPELLERThe pilot should make note of the condition of theengine cowling. [Figure 2-8] If the cowling rivet headsreveal aluminum oxide residue, and chipped paintsurrounding and radiating away from the cowling rivetheads, it is a sign that the rivets have been rotating untilthe holes have been elongated. If allowed to continue,

the cowling may eventually separate from the airplanein flight.

Certain engine/propeller combinations requireinstallation of a prop spinner for proper enginecooling. In these cases, the engine should not beoperated unless the spinner is present and properlyinstalled. The pilot should inspect the propellerspinner and spinner mounting plate for security ofattachment, any signs of chafing of propeller blades,and defects such as cracking. A cracked spinner isunairworthy.

The propeller should be checked for nicks, cracks,pitting, corrosion, and security. The propeller hubshould be checked for oil leaks, and the alternator/generator drive belt should be checked for propertension and signs of wear.

When inspecting inside the cowling, the pilot shouldlook for signs of fuel dye which may indicate a fuelleak. The pilot should check for oil leaks, deteriorationof oil lines, and to make certain that the oil cap, filter,oil cooler and drain plug are secure. The exhaustsystem should be checked for white stains caused byexhaust leaks at the cylinder head or cracks in thestacks. The heat muffs should also be checked forgeneral condition and signs of cracks or leaks.

The air filter should be checked for condition andsecure fit, as well as hydraulic lines for deteriorationand/or leaks. The pilot should also check for loose orforeign objects inside the cowling such as bird nests,shop rags, and/or tools. All visible wires and linesshould be checked for security and condition. Andlastly, when the cowling is closed, the cowlingfasteners should be checked for security.

Figure 2-8. Check the propeller and inside the cowling.

Ch 02.qxd 5/7/04 6:22 AM Page 2-6

2-7

COCKPIT MANAGEMENTAfter entering the airplane, the pilot should first ensurethat all necessary equipment, documents, checklists,and navigation charts appropriate for the flight are onboard. If a portable intercom, headsets, or a hand-heldglobal positioning system (GPS) is used, the pilot isresponsible for ensuring that the routing of wires andcables does not interfere with the motion or theoperation of any control.

Regardless of what materials are to be used, theyshould be neatly arranged and organized in a mannerthat makes them readily available. The cockpit andcabin should be checked for articles that might betossed about if turbulence is encountered. Loose itemsshould be properly secured. All pilots should form thehabit of good housekeeping.

The pilot must be able to see inside and outsidereferences. If the range of motion of an adjustable seatis inadequate, cushions should be used to provide theproper seating position.

When the pilot is comfortably seated, the safety beltand shoulder harness (if installed) should be fastenedand adjusted to a comfortably snug fit. The shoulderharness must be worn at least for the takeoff andlanding, unless the pilot cannot reach or operate thecontrols with it fastened. The safety belt must be wornat all times when the pilot is seated at the controls.

If the seats are adjustable, it is important to ensure thatthe seat is locked in position. Accidents have occurredas the result of seat movement during acceleration orpitch attitude changes during takeoffs or landings.When the seat suddenly moves too close or too faraway from the controls, the pilot may be unable tomaintain control of the airplane.

14 CFR part 91 requires the pilot to ensure that eachperson on board is briefed on how to fasten andunfasten his/her safety belt and, if installed, shoulderharness. This should be accomplished before startingthe engine, along with a passenger briefing on theproper use of safety equipment and exit information.Airplane manufacturers have printed briefing cardsavailable, similar to those used by airlines, tosupplement the pilot’s briefing.

GROUND OPERATIONSIt is important that a pilot operates an airplane safelyon the ground. This includes being familiar withstandard hand signals that are used by ramp personnel.[Figure 2-9]

ENGINE STARTINGThe specific procedures for engine starting will not bediscussed here since there are as many different

methods as there are different engines, fuel systems,and starting conditions. The before engine starting andengine starting checklist procedures should be fol-lowed. There are, however, certain precautions thatapply to all airplanes.

Some pilots have started the engine with the tail of theairplane pointed toward an open hangar door, parkedautomobiles, or a group of bystanders. This is not onlydiscourteous, but may result in personal injury anddamage to the property of others. Propeller blast canbe surprisingly powerful.

When ready to start the engine, the pilot should look inall directions to be sure that nothing is or will be in thevicinity of the propeller. This includes nearby personsand aircraft that could be struck by the propeller blastor the debris it might pick up from the ground. Theanticollision light should be turned on prior to enginestart, even during daytime operations. At night, theposition (navigation) lights should also be on.

The pilot should always call “CLEAR” out of the sidewindow and wait for a response from persons who maybe nearby before activating the starter.

Figure 2-9. Standard hand signals.

Ch 02.qxd 5/7/04 6:22 AM Page 2-7

2-8

When activating the starter, one hand should be kepton the throttle. This allows prompt response if theengine falters during starting, and allows the pilot torapidly retard the throttle if revolutions per minute(r.p.m.) are excessive after starting. A low r.p.m.setting (800 to 1,000) is recommended immediatelyfollowing engine start. It is highly undesirable to allowthe r.p.m. to race immediately after start, as there willbe insufficient lubrication until the oil pressure rises.In freezing temperatures, the engine will also beexposed to potential mechanical distress until it warmsand normal internal operating clearances are assumed.

As soon as the engine is operating smoothly, the oilpressure should be checked. If it does not rise to themanufacturer’s specified value, the engine may not bereceiving proper lubrication and should be shut downimmediately to prevent serious damage.

Although quite rare, the starter motor may remain onand engaged after the engine starts. This can bedetected by a continuous very high current draw on theammeter. Some airplanes also have a starter engagedwarning light specifically for this purpose. The engineshould be shut down immediately should this occur.

Starters are small electric motors designed to drawlarge amounts of current for short periods of cranking.Should the engine fail to start readily, avoidcontinuous starter operation for periods longer than 30seconds without a cool down period of at least 30seconds to a minute (some AFM/POH specify evenlonger). Their service life is drastically shortened fromhigh heat through overuse.

HAND PROPPINGEven though most airplanes are equipped with electricstarters, it is helpful if a pilot is familiar with the pro-cedures and dangers involved in starting an engine byturning the propeller by hand (hand propping). Due tothe associated hazards, this method of starting shouldbe used only when absolutely necessary and whenproper precautions have been taken.

An engine should not be hand propped unless twopeople, both familiar with the airplane and handpropping techniques, are available to perform theprocedure. The person pulling the propeller bladesthrough directs all activity and is in charge of theprocedure. The other person, thoroughly familiarwith the controls, must be seated in the airplane withthe brakes set. As an additional precaution, chocksmay be placed in front of the main wheels. If this isnot feasible, the airplane’s tail may be securely tied.Never allow a person unfamiliar with the controls tooccupy the pilot’s seat when hand propping. Theprocedure should never be attempted alone.

When hand propping is necessary, the ground surfacenear the propeller should be stable and free of debris.Unless a firm footing is available, consider relocatingthe airplane. Loose gravel, wet grass, mud, oil, ice, orsnow might cause the person pulling the propellerthrough to slip into the rotating blades as the enginestarts.

Both participants should discuss the procedure andagree on voice commands and expected action. Tobegin the procedure, the fuel system and enginecontrols (tank selector, primer, pump, throttle, andmixture) are set for a normal start. The ignition/magneto switch should be checked to be sure that it isOFF. Then the descending propeller blade should berotated so that it assumes a position slightly above thehorizontal. The person doing the hand propping shouldface the descending blade squarely and stand slightlyless than one arm’s length from the blade. If a stancetoo far away were assumed, it would be necessary tolean forward in an unbalanced condition to reach theblade. This may cause the person to fall forward intothe rotating blades when the engine starts.

The procedure and commands for hand propping are:

Person out front says, “GAS ON, SWITCH OFF,THROTTLE CLOSED, BRAKES SET.”

Pilot seat occupant, after making sure the fuel isON, mixture is RICH, ignition/magneto switch isOFF, throttle is CLOSED, and brakes SET, says,“GAS ON, SWITCH OFF, THROTTLECLOSED, BRAKES SET.”

Person out front, after pulling the propellerthrough to prime the engine says, “BRAKESAND CONTACT.”

Pilot seat occupant checks the brakes SET andturns the ignition switch ON, then says,“BRAKES AND CONTACT.”

The propeller is swung by forcing the blade downwardrapidly, pushing with the palms of both hands. If theblade is gripped tightly with the fingers, the person’sbody may be drawn into the propeller blades shouldthe engine misfire and rotate momentarily in theopposite direction. As the blade is pushed down, theperson should step backward, away from the propeller.If the engine does not start, the propeller should not berepositioned for another attempt until it is certain theignition/magneto switch is turned OFF.

The words CONTACT (mags ON) and SWITCH OFF(mags OFF) are used because they are significantlydifferent from each other. Under noisy conditions orhigh winds, the words CONTACT and SWITCH OFF

•

•

•

•

Ch 02.qxd 5/7/04 6:22 AM Page 2-8

2-9

are less likely to be misunderstood than SWITCH ONand SWITCH OFF.

When removing the wheel chocks after the enginestarts, it is essential that the pilot remember that thepropeller is almost invisible. Incredible as it may seem,serious injuries and fatalities occur when people whohave just started an engine walk or reach into thepropeller arc to remove the chocks. Before the chocksare removed, the throttle should be set to idle and thechocks approached from the rear of the propeller.Never approach the chocks from the front or the side.

The procedures for hand propping should always be inaccordance with the manufacturer’s recommendationsand checklist. Special starting procedures are usedwhen the engine is already warm, very cold, or whenflooded or vapor locked. There will also be a differentstarting procedure when an external power sourceis used.

TAXIINGThe following basic taxi information is applicable toboth nosewheel and tailwheel airplanes.

Taxiing is the controlled movement of the airplaneunder its own power while on the ground. Since anairplane is moved under its own power between theparking area and the runway, the pilot must thoroughlyunderstand and be proficient in taxi procedures.

An awareness of other aircraft that are taking off,landing, or taxiing, and consideration for the right-of-way of others is essential to safety. When taxiing, thepilot’s eyes should be looking outside the airplane, tothe sides, as well as the front. The pilot must be awareof the entire area around the airplane to ensure that theairplane will clear all obstructions and other aircraft. Ifat any time there is doubt about the clearance from anobject, the pilot should stop the airplane and havesomeone check the clearance. It may be necessary tohave the airplane towed or physically moved by aground crew.

It is difficult to set any rule for a single, safe taxiingspeed. What is reasonable and prudent under someconditions may be imprudent or hazardous under oth-ers. The primary requirements for safe taxiing are pos-itive control, the ability to recognize potential hazardsin time to avoid them, and the ability to stop or turnwhere and when desired, without undue reliance on thebrakes. Pilots should proceed at a cautious speed oncongested or busy ramps. Normally, the speed shouldbe at the rate where movement of the airplane isdependent on the throttle. That is, slow enough sowhen the throttle is closed, the airplane can be stoppedpromptly. When yellow taxiway centerline stripes areprovided, they should be observed unless necessary toclear airplanes or obstructions.

When taxiing, it is best to slow down beforeattempting a turn. Sharp, high-speed turns placeundesirable side loads on the landing gear and mayresult in an uncontrollable swerve or a ground loop.This swerve is most likely to occur when turning froma downwind heading toward an upwind heading. Inmoderate to high-wind conditions, pilots will note theairplane’s tendency to weathervane, or turn into thewind when the airplane is proceeding crosswind.

When taxiing at appropriate speeds in no-windconditions, the aileron and elevator control surfaceshave little or no effect on directional control of theairplane. The controls should not be consideredsteering devices and should be held in a neutralposition. Their proper use while taxiing in windyconditions will be discussed later. [Figure 2-10]

Steering is accomplished with rudder pedals andbrakes. To turn the airplane on the ground, the pilotshould apply rudder in the desired direction of turn anduse whatever power or brake that is necessary tocontrol the taxi speed. The rudder pedal should be heldin the direction of the turn until just short of the pointwhere the turn is to be stopped. Rudder pressure is thenreleased or opposite pressure is applied as needed.

More engine power may be required to start theairplane moving forward, or to start a turn, than isrequired to keep it moving in any given direction.When using additional power, the throttle shouldimmediately be retarded once the airplane beginsmoving, to prevent excessive acceleration.

When first beginning to taxi, the brakes should betested for proper operation as soon as the airplane isput in motion. Applying power to start the airplane

Use Up Aileronon LH Wing andNeutral Elevator

Use Up Aileronon RH Wing andNeutral Elevator

Use Down Aileronon LH Wing andDown Elevator

Use Down Aileronon RH Wing andDown Elevator

Figure 2-10. Flight control positions during taxi.

Ch 02.qxd 5/7/04 6:22 AM Page 2-9

2-10

moving forward slowly, then retarding the throttle andsimultaneously applying pressure smoothly to bothbrakes does this. If braking action is unsatisfactory, theengine should be shut down immediately.

The presence of moderate to strong headwinds and/ora strong propeller slipstream makes the use of theelevator necessary to maintain control of the pitchattitude while taxiing. This becomes apparent whenconsidering the lifting action that may be created onthe horizontal tail surfaces by either of those twofactors. The elevator control in nosewheel-typeairplanes should be held in the neutral position, whilein tailwheel-type airplanes it should be held in the aftposition to hold the tail down.

Downwind taxiing will usually require less enginepower after the initial ground roll is begun, since thewind will be pushing the airplane forward. [Figure2-11] To avoid overheating the brakes when taxiingdownwind, keep engine power to a minimum. Ratherthan continuously riding the brakes to control speed, itis better to apply brakes only occasionally. Other thansharp turns at low speed, the throttle should always beat idle before the brakes are applied. It is a commonstudent error to taxi with a power setting that requirescontrolling taxi speed with the brakes. This is theaeronautical equivalent of driving an automobile withboth the accelerator and brake pedals depressed.

When taxiing with a quartering headwind, the wing onthe upwind side will tend to be lifted by the windunless the aileron control is held in that direction(upwind aileron UP). [Figure 2-12] Moving the aileron

into the UP position reduces the effect of the windstriking that wing, thus reducing the lifting action.This control movement will also cause the downwindaileron to be placed in the DOWN position, thus asmall amount of lift and drag on the downwind wing,further reducing the tendency of the upwind wingto rise.

When taxiing with a quartering tailwind, the elevatorshould be held in the DOWN position, and the upwindaileron, DOWN. [Figure 2-13] Since the wind isstriking the airplane from behind, these controlpositions reduce the tendency of the wind to get underthe tail and the wing and to nose the airplane over.

The application of these crosswind taxi correctionshelps to minimize the weathervaning tendency andultimately results in making the airplane easier tosteer.

Normally, all turns should be started using the rudderpedal to steer the nosewheel. To tighten the turn afterfull pedal deflection is reached, the brake may beapplied as needed. When stopping the airplane, it isadvisable to always stop with the nosewheel straightahead to relieve any side load on the nosewheel and tomake it easier to start moving ahead.

During crosswind taxiing, even the nosewheel-typeairplane has some tendency to weathervane. However,

WHEN TAXIING DOWNWIND

Keep engine powerto a minimum.

Do not ride the brakes. Reduce power and use

brakes intermittently.

Figure 2-11. Downwind taxi.

Upwind Aileron Up

Downwind Aileron Down

Elevator Neutral

Figure 2-12. Quartering headwind.

Upwind Aileron Down

Downwind Aileron Up

Elevator Down

Figure 2-13. Quartering tailwind.

Figure 2-14. Surface area most affected by wind.

Ch 02.qxd 5/7/04 6:22 AM Page 2-10

2-11

the weathervaning tendency is less than intailwheel-type airplanes because the main wheels arelocated farther aft, and the nosewheel’s ground frictionhelps to resist the tendency. [Figure 2-14] Thenosewheel linkage from the rudder pedals providesadequate steering control for safe and efficient groundhandling, and normally, only rudder pressure isnecessary to correct for a crosswind.

BEFORE TAKEOFF CHECKThe before takeoff check is the systematic procedurefor making a check of the engine, controls, systems,instruments, and avionics prior to flight. Normally, it isperformed after taxiing to a position near the takeoffend of the runway. Taxiing to that position usuallyallows sufficient time for the engine to warm up to atleast minimum operating temperatures. This ensuresadequate lubrication and internal engine clearancesbefore being operated at high power settings. Manyengines require that the oil temperature reach aminimum value as stated in the AFM/POH before highpower is applied.

Air-cooled engines generally are closely cowled andequipped with pressure baffles that direct the flow ofair to the engine in sufficient quantities for cooling inflight. On the ground, however, much less air is forcedthrough the cowling and around the baffling.Prolonged ground operations may cause cylinderoverheating long before there is an indication of risingoil temperature. Cowl flaps, if available, should be setaccording to the AFM/POH.

Before beginning the before takeoff check, the airplaneshould be positioned clear of other aircraft. Thereshould not be anything behind the airplane that mightbe damaged by the prop blast. To minimizeoverheating during engine runup, it is recommendedthat the airplane be headed as nearly as possible intothe wind. After the airplane is properly positioned forthe runup, it should be allowed to roll forward slightlyso that the nosewheel or tailwheel will be aligned foreand aft.

During the engine runup, the surface under the airplaneshould be firm (a smooth, paved, or turf surface ifpossible) and free of debris. Otherwise, the propellermay pick up pebbles, dirt, mud, sand, or other looseobjects and hurl them backwards. This damages thepropeller and may damage the tail of the airplane.Small chips in the leading edge of the propeller formstress risers, or lines of concentrated high stress. Theseare highly undesirable and may lead to cracks andpossible propeller blade failure.

While performing the engine runup, the pilot mustdivide attention inside and outside the airplane. If the

parking brake slips, or if application of the toe brakesis inadequate for the amount of power applied, theairplane could move forward unnoticed if attention isfixed inside the airplane.

Each airplane has different features and equipment,and the before takeoff checklist provided by theairplane manufacturer or operator should be used toperform the runup.

AFTER LANDINGDuring the after-landing roll, the airplane should begradually slowed to normal taxi speed before turningoff the landing runway. Any significant degree of turnat faster speeds could result in ground looping andsubsequent damage to the airplane.

To give full attention to controlling the airplane duringthe landing roll, the after-landing check should beperformed only after the airplane is brought to acomplete stop clear of the active runway. There havebeen many cases of the pilot mistakenly grasping thewrong handle and retracting the landing gear, insteadof the flaps, due to improper division of attention whilethe airplane was moving. However, this procedure maybe modified if the manufacturer recommends thatspecific after-landing items be accomplished duringlanding rollout. For example, when performing ashort-field landing, the manufacturer may recommendretracting the flaps on rollout to improve braking. Inthis situation, the pilot should make a positiveidentification of the flap control and retract the flaps.

CLEAR OF RUNWAYBecause of different features and equipment in variousairplanes, the after-landing checklist provided by themanufacturer should be used. Some of the items mayinclude:

• Flaps . . . . . . . . . . . . . . . Identify and retract

• Cowl flaps . . . . . . . . . . . . . . . . . . . . . Open

• Propeller control . . . . . . . . . . . Full increase

• Trim tabs . . . . . . . . . . . . . . . . . . . . . . . . Set

PARKINGUnless parking in a designated, supervised area, thepilot should select a location and heading which willprevent the propeller or jet blast of other airplanes fromstriking the airplane broadside. Whenever possible, theairplane should be parked headed into the existing orforecast wind. After stopping on the desired heading,the airplane should be allowed to roll straight aheadenough to straighten the nosewheel or tailwheel.

Ch 02.qxd 5/7/04 6:22 AM Page 2-11

2-12

ENGINE SHUTDOWNFinally, the pilot should always use the procedures inthe manufacturer’s checklist for shutting down theengine and securing the airplane. Some of the impor-tant items include:

Set the parking brakes ON.

Set throttle to IDLE or 1,000 r.p.m. If tur-bocharged, observe the manufacturer’s spooldown procedure.

Turn ignition switch OFF then ON at idle tocheck for proper operation of switch in the OFFposition.

Set propeller control (if equipped) to FULLINCREASE.

Turn electrical units and radios OFF.

Set mixture control to IDLE CUTOFF.

Turn ignition switch to OFF when engine stops.

Turn master electrical switch to OFF.

Install control lock.

POSTFLIGHTA flight is never complete until the engine is shut downand the airplane is secured. A pilot should consider thisan essential part of any flight.

SECURING AND SERVICINGAfter engine shutdown and deplaning passengers, thepilot should accomplish a postflight inspection. Thisincludes checking the general condition of the aircraft.For a departure, the oil should be checked and fueladded if required. If the aircraft is going to be inactive,it is a good operating practice to fill the tanks to thetop to prevent water condensation from forming.When the flight is completed for the day, the aircraftshould be hangared or tied down and the flightcontrols secured.

•

•

•

•

•

•

•

•

•

Ch 02.qxd 5/7/04 6:22 AM Page 2-12

3-1

THE FOUR FUNDAMENTALSThere are four fundamental basic flight maneuversupon which all flying tasks are based: straight-and-level flight, turns, climbs, and descents. All controlled flight consists of either one, or a combinationor more than one, of these basic maneuvers. If a studentpilot is able to perform these maneuvers well, and thestudent’s proficiency is based on accurate “feel” andcontrol analysis rather than mechanical movements, theability to perform any assigned maneuver will only bea matter of obtaining a clear visual and mental concep-tion of it. The flight instructor must impart a goodknowledge of these basic elements to the student, andmust combine them and plan their practice so thatperfect performance of each is instinctive withoutconscious effort. The importance of this to the successof flight training cannot be overemphasized. As thestudent progresses to more complex maneuvers,discounting any difficulties in visualizing themaneuvers, most student difficulties will be caused bya lack of training, practice, or understanding of theprinciples of one or more of these fundamentals.

EFFECTS AND USE OF THE CONTROLSIn explaining the functions of the controls, the instructorshould emphasize that the controls never change in theresults produced in relation to the pilot. The pilot shouldalways be considered the center of movement of the air-plane, or the reference point from which the movementsof the airplane are judged and described. The followingwill always be true, regardless of the airplane’s attitudein relation to the Earth.

• When back pressure is applied to the elevator con-trol, the airplane’s nose rises in relation to the pilot.

• When forward pressure is applied to the elevatorcontrol, the airplane’s nose lowers in relation to thepilot.

• When right pressure is applied to the aileron con-trol, the airplane’s right wing lowers in relation tothe pilot.

• When left pressure is applied to the aileron control,the airplane’s left wing lowers in relation to thepilot.

• When pressure is applied to the right rudder pedal,the airplane’s nose moves (yaws) to the right inrelation to the pilot.

• When pressure is applied to the left rudder pedal,the airplane’s nose moves (yaws) to the left inrelation to the pilot.

The preceding explanations should prevent thebeginning pilot from thinking in terms of “up” or“down” in respect to the Earth, which is only a relativestate to the pilot. It will also make understanding of thefunctions of the controls much easier, particularlywhen performing steep banked turns and the moreadvanced maneuvers. Consequently, the pilot must beable to properly determine the control applicationrequired to place the airplane in any attitude or flightcondition that is desired.

The flight instructor should explain that the controlswill have a natural “live pressure” while in flight andthat they will remain in neutral position of their ownaccord, if the airplane is trimmed properly.

With this in mind, the pilot should be cautionednever to think of movement of the controls, but ofexerting a force on them against this live pressure orresistance. Movement of the controls should not beemphasized; it is the duration and amount of theforce exerted on them that effects the displacementof the control surfaces and maneuvers the airplane.

The amount of force the airflow exerts on a controlsurface is governed by the airspeed and the degree thatthe surface is moved out of its neutral or streamlinedposition. Since the airspeed will not be the same in allmaneuvers, the actual amount the control surfaces aremoved is of little importance; but it is important thatthe pilot maneuver the airplane by applying sufficientcontrol pressure to obtain a desired result, regardlessof how far the control surfaces are actually moved.

The controls should be held lightly, with the fingers,not grabbed and squeezed. Pressure should be exertedon the control yoke with the fingers. A common errorin beginning pilots is a tendency to “choke the stick.”This tendency should be avoided as it prevents thedevelopment of “feel,” which is an important part ofaircraft control.

The pilot’s feet should rest comfortably against therudder pedals. Both heels should support the weightof the feet on the cockpit floor with the ball of eachfoot touching the individual rudder pedals. The legsand feet should not be tense; they must be relaxedjust as when driving an automobile.

Ch 03.qxd 7/13/04 11:08 AM Page 3-1

3-2

When using the rudder pedals, pressure should beapplied smoothly and evenly by pressing with the ballof one foot. Since the rudder pedals are interconnected,and act in opposite directions, when pressure is appliedto one pedal, pressure on the other must be relaxed pro-portionately. When the rudder pedal must be movedsignificantly, heavy pressure changes should be madeby applying the pressure with the ball of the foot whilethe heels slide along the cockpit floor. Remember, theball of each foot must rest comfortably on the rudderpedals so that even slight pressure changes can be felt.

In summary, during flight, it is the pressure the pilotexerts on the control yoke and rudder pedals thatcauses the airplane to move about its axes. When acontrol surface is moved out of its streamlined position(even slightly), the air flowing past it will exert a forceagainst it and will try to return it to its streamlined posi-tion. It is this force that the pilot feels as pressure onthe control yoke and the rudder pedals.

FEEL OF THE AIRPLANEThe ability to sense a flight condition, without relyingon cockpit instrumentation, is often called “feel of theairplane,” but senses in addition to “feel” are involved.

Sounds inherent to flight are an important sense indeveloping “feel.” The air that rushes past the mod-ern light plane cockpit/cabin is often masked bysoundproofing, but it can still be heard. When thelevel of sound increases, it indicates that airspeed isincreasing. Also, the powerplant emits distinctivesound patterns in different conditions of flight. Thesound of the engine in cruise flight may be differentfrom that in a climb, and different again from that ina dive. When power is used in fixed-pitch propellerairplanes, the loss of r.p.m. is particularly notice-able. The amount of noise that can be heard willdepend on how much the slipstream masks it out.But the relationship between slipstream noise andpowerplant noise aids the pilot in estimating notonly the present airspeed but the trend of the air-speed.

There are three sources of actual “feel” that are veryimportant to the pilot. One is the pilot’s own body asit responds to forces of acceleration. The “G” loadsimposed on the airframe are also felt by the pilot.Centripetal accelerations force the pilot down into theseat or raise the pilot against the seat belt. Radialaccelerations, as they produce slips or skids of the air-frame, shift the pilot from side to side in the seat.These forces need not be strong, only perceptible bythe pilot to be useful. An accomplished pilot who hasexcellent “feel” for the airplane will be able to detecteven the minutest change.

The response of the aileron and rudder controls to thepilot’s touch is another element of “feel,” and is one

that provides direct information concerning airspeed.As previously stated, control surfaces move in theairstream and meet resistance proportional to thespeed of the airstream. When the airstream is fast, thecontrols are stiff and hard to move. When the airstreamis slow, the controls move easily, but must be deflecteda greater distance. The pressure that must be exertedon the controls to effect a desired result, and the lagbetween their movement and the response of the air-plane, becomes greater as airspeed decreases.

Another type of “feel” comes to the pilot through theairframe. It consists mainly of vibration. An exampleis the aerodynamic buffeting and shaking that precedesa stall.

Kinesthesia, or the sensing of changes in direction orspeed of motion, is one of the most important senses apilot can develop. When properly developed, kines-thesia can warn the pilot of changes in speed and/orthe beginning of a settling or mushing of the airplane.

The senses that contribute to “feel” of the airplane areinherent in every person. However, “feel” must bedeveloped. The flight instructor should direct thebeginning pilot to be attuned to these senses and teachan awareness of their meaning as it relates to variousconditions of flight. To do this effectively, the flightinstructor must fully understand the differencebetween perceiving something and merely noticing it.It is a well established fact that the pilot who developsa “feel” for the airplane early in flight training willhave little difficulty with advanced flight maneuvers.

ATTITUDE FLYINGIn contact (VFR) flying, flying by attitude means visu-ally establishing the airplane’s attitude with referenceto the natural horizon. [Figure 3-1] Attitude is theangular difference measured between an airplane’saxis and the line of the Earth’s horizon. Pitch attitudeis the angle formed by the longitudinal axis, and bankattitude is the angle formed by the lateral axis.Rotation about the airplane’s vertical axis (yaw) istermed an attitude relative to the airplane’s flightpath,but not relative to the natural horizon.

In attitude flying, airplane control is composed of fourcomponents: pitch control, bank control, power con-trol, and trim.

• Pitch control is the control of the airplane aboutthe lateral axis by using the elevator to raise andlower the nose in relation to the natural horizon.

• Bank control is control of the airplane about the lon-gitudinal axis by use of the ailerons to attain a desiredbank angle in relation to the natural horizon.

Ch 03.qxd 7/13/04 11:08 AM Page 3-2

3-3

• Power control is used when the flight situationindicates a need for a change in thrust.

• Trim is used to relieve all possible control pres-sures held after a desired attitude has beenattained.

The primary rule of attitude flying is:

ATTITUDE + POWER = PERFORMANCE

INTEGRATED FLIGHT INSTRUCTIONWhen introducing basic flight maneuvers to a beginningpilot, it is recommended that the “Integrated” or“Composite” method of flight instruction be used. Thismeans the use of outside references and flight instru-ments to establish and maintain desired flight attitudesand airplane performance. [Figure 3-2] When beginningpilots use this technique, they achieve a more preciseand competent overall piloting ability. Although thismethod of airplane control may become second naturewith experience, the beginning pilot must make a deter-mined effort to master the technique. The basic elementsof which are as follows.

• The airplane’s attitude is established and main-tained by positioning the airplane in relation to thenatural horizon. At least 90 percent of the pilot’sattention should be devoted to this end, along with

PITCH CONTROL

BANK CONTROL

Figure 3-1. Airplane attitude is based on relative positions of the nose and wings on the natural horizon.

No more than10% of the pilot's attention shouldbe inside thecockpit.

90% of the time, the pilot's attention shouldbe outside the cockpit.

Figure 3-2. Integrated or composite method of flight instruction.

Ch 03.qxd 7/13/04 11:08 AM Page 3-3

3-4

scanning for other airplanes. If, during a recheck ofthe pitch and/or bank, either or both are found to beother than desired, an immediate correction is madeto return the airplane to the proper attitude.Continuous checks and immediate corrections willallow little chance for the airplane to deviate fromthe desired heading, altitude, and flightpath.

• The airplane’s attitude is confirmed by referring toflight instruments, and its performance checked. Ifairplane performance, as indicated by flight instru-ments, indicates a need for correction, a specificamount of correction must be determined, thenapplied with reference to the natural horizon. The air-plane’s attitude and performance are then recheckedby referring to flight instruments. The pilot thenmaintains the corrected attitude by reference to thenatural horizon.

• The pilot should monitor the airplane’s perform-ance by making numerous quick glances at theflight instruments. No more than 10 percent of thepilot’s attention should be inside the cockpit. Thepilot must develop the skill to instantly focus onthe appropriate flight instrument, and then imme-diately return to outside reference to control theairplane’s attitude.

The pilot should become familiar with the relationshipbetween outside references to the natural horizon andthe corresponding indications on flight instrumentsinside the cockpit. For example, a pitch attitude adjust-ment may require a movement of the pilot’s referencepoint on the airplane of several inches in relation to thenatural horizon, but correspond to a small fraction ofan inch movement of the reference bar on the air-plane’s attitude indicator. Similarly, a deviation fromdesired bank, which is very obvious when referencingthe wingtip’s position relative to the natural horizon,may be nearly imperceptible on the airplane’s attitudeindicator to the beginning pilot.

The use of integrated flight instruction does not, and isnot intended to prepare pilots for flight in instrumentweather conditions. The most common error made by thebeginning student is to make pitch or bank correctionswhile still looking inside the cockpit. Control pressure isapplied, but the beginning pilot, not being familiar withthe intricacies of flight by references to instruments,including such things as instrument lag and gyroscopicprecession, will invariably make excessive attitude cor-rections and end up “chasing the instruments.” Airplaneattitude by reference to the natural horizon, however, isimmediate in its indications, accurate, and presentedmany times larger than any instrument could be. Also,the beginning pilot must be made aware that anytime, forwhatever reason, airplane attitude by reference to the nat-ural horizon cannot be established and/or maintained, thesituation should be considered a bona fide emergency.

STRAIGHT-AND-LEVEL FLIGHTIt is impossible to emphasize too strongly the neces-sity for forming correct habits in flying straight andlevel. All other flight maneuvers are in essence adeviation from this fundamental flight maneuver.Many flight instructors and students are prone tobelieve that perfection in straight-and-level flightwill come of itself, but such is not the case. It is notuncommon to find a pilot whose basic flying abilityconsistently falls just short of minimum expectedstandards, and upon analyzing the reasons for theshortcomings to discover that the cause is the inabil-ity to fly straight and level properly.

Straight-and-level flight is flight in which a constantheading and altitude are maintained. It is accomplishedby making immediate and measured corrections for devia-tions in direction and altitude from unintentional slightturns, descents, and climbs. Level flight, at first, is a matterof consciously fixing the relationship of the position ofsome portion of the airplane, used as a reference point, withthe horizon. In establishing the reference points, theinstructor should place the airplane in the desired positionand aid the student in selecting reference points. Theinstructor should be aware that no two pilots see this rela-tionship exactly the same. The references will depend onwhere the pilot is sitting, the pilot’s height (whether shortor tall), and the pilot’s manner of sitting. It is, therefore,important that during the fixing of this relationship, thepilot sit in a normal manner; otherwise the points will notbe the same when the normal position is resumed.

In learning to control the airplane in level flight, it isimportant that the student be taught to maintain a lightgrip on the flight controls, and that the control forcesdesired be exerted lightly and just enough to producethe desired result. The student should learn to associ-ate the apparent movement of the references with theforces which produce it. In this way, the student candevelop the ability to regulate the change desired inthe airplane’s attitude by the amount and direction offorces applied to the controls without the necessity ofreferring to instrument or outside references for eachminor correction.

The pitch attitude for level flight (constant altitude) isusually obtained by selecting some portion of the air-plane’s nose as a reference point, and then keepingthat point in a fixed position relative to the horizon.[Figure 3-3] Using the principles of attitude flying,that position should be cross-checked occasionallyagainst the altimeter to determine whether or not thepitch attitude is correct. If altitude is being gained orlost, the pitch attitude should be readjusted in rela-tion to the horizon and then the altimeter recheckedto determine if altitude is now being maintained. The

Ch 03.qxd 7/13/04 11:08 AM Page 3-4

3-5

application of forward or back-elevator pressure isused to control this attitude.

The pitch information obtained from the attitude indi-cator also will show the position of the nose relative tothe horizon and will indicate whether elevator pressureis necessary to change the pitch attitude to return tolevel flight. However, the primary reference source isthe natural horizon.

In all normal maneuvers, the term “increase the pitchattitude” implies raising the nose in relation to the hori-zon; the term “decreasing the pitch attitude” meanslowering the nose.

Straight flight (laterally level flight) is accomplishedby visually checking the relationship of the airplane’swingtips with the horizon. Both wingtips should beequidistant above or below the horizon (depending onwhether the airplane is a high-wing or low-wing type),and any necessary adjustments should be made withthe ailerons, noting the relationship of control pressureand the airplane’s attitude. [Figure 3-4] The studentshould understand that anytime the wings are banked,even though very slightly, the airplane will turn. Theobjective of straight-and-level flight is to detect smalldeviations from laterally level flight as soon as theyoccur, necessitating only small corrections. Referenceto the heading indicator should be made to note anychange in direction.

STRAIGHT AND LEVEL

Fixed

Reference Point

Figure 3-3. Nose reference for straight-and-level flight.

Figure 3-4. Wingtip reference for straight-and-level flight.

Ch 03.qxd 7/13/04 11:08 AM Page 3-5

3-6

Continually observing the wingtips has advantagesother than being the only positive check for leveling thewings. It also helps divert the pilot’s attention from theairplane’s nose, prevents a fixed stare, and automaticallyexpands the pilot’s area of vision by increasing the rangenecessary for the pilot’s vision to cover. In practicingstraight-and-level-flight, the wingtips can be used notonly for establishing the airplane’s laterally level atti-tude or bank, but to a lesser degree, its pitch attitude.This is noted only for assistance in learning straight-and-level flight, and is not a recommended practice in nor-mal operations.

The scope of a student’s vision is also very important,for if it is obscured the student will tend to look out toone side continually (usually the left) and consequentlylean that way. This not only gives the student a biasedangle from which to judge, but also causes the studentto exert unconscious pressure on the controls in thatdirection, which results in dragging a wing.

With the wings approximately level, it is possible tomaintain straight flight by simply exerting the neces-sary forces on the rudder in the desired direction.However, the instructor should point out that thepractice of using rudder alone is not correct and maymake precise control of the airplane difficult.Straight–and-level flight requires almost no applica-tion of control pressures if the airplane is properlytrimmed and the air is smooth. For that reason, thestudent must not form the habit of constantly movingthe controls unnecessarily. The student must learn torecognize when corrections are necessary, and then tomake a measured response easily and naturally.

To obtain the proper conception of the forcesrequired on the rudder during straight-and-level-flight, the airplane must be held level. One of themost common faults of beginning students is thetendency to concentrate on the nose of the airplaneand attempting to hold the wings level by observingthe curvature of the nose cowling. With this method,the reference line is very short and the deviation,particularly if very slight, can go unnoticed. Also, avery small deviation from level, by this short refer-ence line, becomes considerable at the wingtips andresults in an appreciable dragging of one wing. Thisattitude requires the use of additional rudder tomaintain straight flight, giving a false conception ofneutral control forces. The habit of dragging onewing, and compensating with rudder pressure, ifallowed to develop is particularly hard to break, andif not corrected will result in considerable difficultyin mastering other flight maneuvers.

For all practical purposes, the airspeed will remain con-stant in straight-and-level flight with a constant powersetting. Practice of intentional airspeed changes, byincreasing or decreasing the power, will provide an

excellent means of developing proficiency in maintain-ing straight-and-level flight at various speeds.Significant changes in airspeed will, of course, requireconsiderable changes in pitch attitude and pitch trim tomaintain altitude. Pronounced changes in pitch attitudeand trim will also be necessary as the flaps and landinggear are operated.

Common errors in the performance of straight-and-level flight are:

• Attempting to use improper reference points onthe airplane to establish attitude.

• Forgetting the location of preselected referencepoints on subsequent flights.

• Attempting to establish or correct airplane attitudeusing flight instruments rather than outside visualreference.

• Attempting to maintain direction using only rud-der control.

• Habitually flying with one wing low.

• “Chasing” the flight instruments rather thanadhering to the principles of attitude flying.

• Too tight a grip on the flight controls resulting inovercontrol and lack of feel.

• Pushing or pulling on the flight controls ratherthan exerting pressure against the airstream.

• Improper scanning and/or devoting insufficienttime to outside visual reference. (Head in thecockpit.)

• Fixation on the nose (pitch attitude) referencepoint.

• Unnecessary or inappropriate control inputs.

• Failure to make timely and measured controlinputs when deviations from straight-and-levelflight are detected.

• Inadequate attention to sensory inputs in develop-ing feel for the airplane.

TRIM CONTROLThe airplane is designed so that the primary flightcontrols (rudder, aileron, and elevator) are stream-lined with the nonmovable airplane surfaces whenthe airplane is cruising straight-and-level at normalweight and loading. If the airplane is flying out ofthat basic balanced condition, one or more of thecontrol surfaces is going to have to be held out of itsstreamlined position by continuous control input.The use of trim tabs relieves the pilot of this require-ment. Proper trim technique is a very important and

Ch 03.qxd 7/13/04 11:08 AM Page 3-6

3-7

often overlooked basic flying skill. An improperlytrimmed airplane requires constant control pressures,produces pilot tension and fatigue, distracts the pilotfrom scanning, and contributes to abrupt and erraticairplane attitude control.

Because of their relatively low power and speed, notall light airplanes have a complete set of trim tabsthat are adjustable from the cockpit. In airplaneswhere rudder, aileron, and elevator trim are avail-able, a definite sequence of trim application shouldbe used. Elevator/stabilator should be trimmed firstto relieve the need for control pressure to maintainconstant airspeed/pitch attitude. Attempts to trim therudder at varying airspeed are impractical in pro-peller driven airplanes because of the change in thetorque correcting offset of the vertical fin. Once aconstant airspeed/pitch attitude has been established,the pilot should hold the wings level with aileronpressure while rudder pressure is trimmed out.Aileron trim should then be adjusted to relieve anylateral control yoke pressure.

A common trim control error is the tendency toovercontrol the airplane with trim adjustments. Toavoid this the pilot must learn to establish and holdthe airplane in the desired attitude using the primaryflight controls. The proper attitude should be estab-lished with reference to the horizon and then veri-fied by reference to performance indications on theflight instruments. The pilot should then apply trimin the above sequence to relieve whatever hand andfoot pressure had been required. The pilot mustavoid using the trim to establish or correct airplaneattitude. The airplane attitude must be establishedand held first, then control pressures trimmed outso that the airplane will maintain the desired atti-tude in “hands off” flight. Attempting to “fly theairplane with the trim tabs” is a common fault inbasic flying technique even among experiencedpilots.

A properly trimmed airplane is an indication of goodpiloting skills. Any control pressures the pilot feelsshould be a result of deliberate pilot control input dur-ing a planned change in airplane attitude, not a resultof pressures being applied by the airplane because thepilot is allowing it to assume control.

LEVEL TURNSA turn is made by banking the wings in the direction ofthe desired turn. A specific angle of bank is selected bythe pilot, control pressures applied to achieve thedesired bank angle, and appropriate control pressuresexerted to maintain the desired bank angle once it isestablished. [Figure 3-5]

All four primary controls are used in close coordina-tion when making turns. Their functions are as follows.

• The ailerons bank the wings and so determine therate of turn at any given airspeed.

• The elevator moves the nose of the airplane up ordown in relation to the pilot, and perpendicular tothe wings. Doing that, it both sets the pitch attitudein the turn and “pulls” the nose of the airplanearound the turn.

• The throttle provides thrust which may be used forairspeed to tighten the turn.

• The rudder offsets any yaw effects developed bythe other controls. The rudder does not turn the air-plane.

For purposes of this discussion, turns are divided intothree classes: shallow turns, medium turns, and steepturns.

• Shallow turns are those in which the bank (lessthan approximately 20°) is so shallow that theinherent lateral stability of the airplane is acting tolevel the wings unless some aileron is applied tomaintain the bank.

• Medium turns are those resulting from a degree ofbank (approximately 20° to 45°) at which the air-plane remains at a constant bank.

Figure 3-5. Level turn to the left.

Ch 03.qxd 7/13/04 11:08 AM Page 3-7

3-8

Steep turns are those resulting from a degree ofbank (45° or more) at which the “overbankingtendency” of an airplane overcomes stability, andthe bank increases unless aileron is applied toprevent it.

Changing the direction of the wing’s lift toward oneside or the other causes the airplane to be pulled in thatdirection. [Figure 3-6] Applying coordinated aileronand rudder to bank the airplane in the direction of thedesired turn does this.

When an airplane is flying straight and level, the total liftis acting perpendicular to the wings and to the Earth. Asthe airplane is banked into a turn, the lift then becomesthe resultant of two components. One, the vertical liftcomponent, continues to act perpendicular to the Earthand opposes gravity. Second, the horizontal lift compo-nent (centripetal) acts parallel to the Earth’s surface andopposes inertia (apparent centrifugal force). These twolift components act at right angles to each other, causingthe resultant total lifting force to act perpendicular to thebanked wing of the airplane. It is the horizontal lift com-ponent that actually turns the airplane—not the rudder.When applying aileron to bank the airplane, the loweredaileron (on the rising wing) produces a greater drag thanthe raised aileron (on the lowering wing). [Figure 3-7]This increased aileron yaws the airplane toward the risingwing, or opposite to the direction of turn. To counteractthis adverse yawing moment, rudder pressure must beapplied simultaneously with aileron in the desireddirection of turn. This action is required to produce acoordinated turn.

After the bank has been established in a mediumbanked turn, all pressure applied to the aileron may berelaxed. The airplane will remain at the selected bank

with no further tendency to yaw since there is nolonger a deflection of the ailerons. As a result, pres-sure may also be relaxed on the rudder pedals, and therudder allowed to streamline itself with the directionof the slipstream. Rudder pressure maintained after theturn is established will cause the airplane to skid to theoutside of the turn. If a definite effort is made to centerthe rudder rather than let it streamline itself to the turn,it is probable that some opposite rudder pressure willbe exerted inadvertently. This will force the airplane toyaw opposite its turning path, causing the airplane toslip to the inside of the turn. The ball in the turn-and-slip indicator will be displaced off-center wheneverthe airplane is skidding or slipping sideways. [Figure3-8] In proper coordinated flight, there is no skiddingor slipping. An essential basic airmanship skill is theability of the pilot to sense or “feel” any uncoordinatedcondition (slip or skid) without referring to instrumentreference. During this stage of training, the flightinstructor should stress the development of this abilityand insist on its use to attain perfect coordination in allsubsequent training.

In all constant altitude, constant airspeed turns, it isnecessary to increase the angle of attack of the wingwhen rolling into the turn by applying up elevator.This is required because part of the vertical lift hasbeen diverted to horizontal lift. Thus, the total lift mustbe increased to compensate for this loss.

To stop the turn, the wings are returned to level flightby the coordinated use of the ailerons and rudderapplied in the opposite direction. To understand therelationship between airspeed, bank, and radius ofturn, it should be noted that the rate of turn at anygiven true airspeed depends on the horizontal lift com-ponent. The horizontal lift component varies in pro-portion to the amount of bank. Therefore, the rate ofturn at a given true airspeed increases as the angle ofbank is increased. On the other hand, when a turn ismade at a higher true airspeed at a given bank angle,the inertia is greater and the horizontal lift componentrequired for the turn is greater, causing the turning rate

Figure 3-6. Change in lift causes airplane to turn.

More lift

Additionalinduced drag

Rudder overcomesadverse yaw tocoordinate the turn

Reduced lift

Figure 3-7. Forces during a turn.

Ch 03.qxd 7/13/04 11:08 AM Page 3-8

3-9

to become slower. [Figure 3-9 on next page] Therefore,at a given angle of bank, a higher true airspeed willmake the radius of turn larger because the airplane willbe turning at a slower rate.

When changing from a shallow bank to a mediumbank, the airspeed of the wing on the outside of the turnincreases in relation to the inside wing as the radius ofturn decreases. The additional lift developed becauseof this increase in speed of the wing balances theinherent lateral stability of the airplane. At any givenairspeed, aileron pressure is not required to maintainthe bank. If the bank is allowed to increase from amedium to a steep bank, the radius of turn decreasesfurther. The lift of the outside wing causes the bank tosteepen and opposite aileron is necessary to keep thebank constant.

As the radius of the turn becomes smaller, a significantdifference develops between the speed of the insidewing and the speed of the outside wing. The wing onthe outside of the turn travels a longer circuit than theinside wing, yet both complete their respective circuitsin the same length of time. Therefore, the outside wingtravels faster than the inside wing, and as a result, itdevelops more lift. This creates an overbankingtendency that must be controlled by the use of theailerons. [Figure 3-10] Because the outboard wing isdeveloping more lift, it also has more induced drag.This causes a slight slip during steep turns that must becorrected by use of the rudder.

Sometimes during early training in steep turns, thenose may be allowed to get excessively low resultingin a significant loss in altitude. To recover, the pilotshould first reduce the angle of bank with coordinateduse of the rudder and aileron, then raise the nose of theairplane to level flight with the elevator. If recoveryfrom an excessively nose-low steep bank condition is

attempted by use of the elevator only, it will cause asteepening of the bank and could result in overstress-ing the airplane. Normally, small corrections for pitchduring steep turns are accomplished with the elevator,and the bank is held constant with the ailerons.

To establish the desired angle of bank, the pilot shoulduse outside visual reference points, as well as the bankindicator on the attitude indicator.

The best outside reference for establishing the degree ofbank is the angle formed by the raised wing of low-wingairplanes (the lowered wing of high-wing airplanes) andthe horizon, or the angle made by the top of the enginecowling and the horizon. [Figure 3-11 on page 3-11]Since on most light airplanes the engine cowling is fairlyflat, its horizontal angle to the horizon will give someindication of the approximate degree of bank. Also,information obtained from the attitude indicator willshow the angle of the wing in relation to the horizon.Information from the turn coordinator, however, will not.

SKID COORDINATED SLIP TURN

Pilot feelssideways forceto outside of turn

Pilot feelsforce straight

down into seat

Pilot feelssideways forceto inside of turn

Ball to outsideof turn

Ball centered Ball to insideof turn

Figure 3-8. Indications of a slip and skid.

OVERBANKING TENDENCY

Outer wing travels greater distance • Higher Speed • More Lift

Inner wing travels shorter distance • Lower speed • Less lift

Figure 3-10. Overbanking tendency during a steep turn.

Ch 03.qxd 7/13/04 11:08 AM Page 3-9

3-10

CONSTANT AIRSPEED

10° Angle of Bank

20° Angle of Bank

30° Angle of Bank

When airspeed is held constant, a larger angle of bank will result in a smaller turn radius and a greater turn rate.

CONSTANT ANGLE OF BANK

When angle of bank is held constant, a slower airspeed will result in a smaller turn radius and greater turn rate.

80 kts

90 kts

100 kts

Figure 3-9. Angle of bank and airspeed regulate rate and radius of turn.

Ch 03.qxd 7/13/04 11:08 AM Page 3-10

3-11

The pilot’s posture while seated in the airplane is veryimportant, particularly during turns. It will affect theinterpretation of outside visual references. At thebeginning, the student may lean away from the turn inan attempt to remain upright in relation to the groundrather than ride with the airplane. This should be cor-rected immediately if the student is to properly learn touse visual references. [Figure 3-12]

Parallax error is common among students and experi-enced pilots. This error is a characteristic of airplanesthat have side-by-side seats because the pilot is seated toone side of the longitudinal axis about which the airplanerolls. This makes the nose appear to rise when making aleft turn and to descend when making right turns. [Figure3-13]

Beginning students should not use large aileron andrudder applications because this produces a rapid rollrate and allows little time for corrections before thedesired bank is reached. Slower (small control dis-placement) roll rates provide more time to makenecessary pitch and bank corrections. As soon asthe airplane rolls from the wings-level attitude, thenose should also start to move along the horizon,increasing its rate of travel proportionately as thebank is increased.

The following variations provide excellent guides.

• If the nose starts to move before the bank starts,rudder is being applied too soon.

• If the bank starts before the nose starts turning, orthe nose moves in the opposite direction, the rud-der is being applied too late.

• If the nose moves up or down when entering abank, excessive or insufficient up elevator is beingapplied.

As the desired angle of bank is established, aileronand rudder pressures should be relaxed. This willstop the bank from increasing because the aileronand rudder control surfaces will be neutral in theirstreamlined position. The up-elevator pressureshould not be relaxed, but should be held constant tomaintain a constant altitude. Throughout the turn, thepilot should cross-check the airspeed indicator, andif the airspeed has decreased more than 5 knots, addi-tional power should be used. The cross-check shouldalso include outside references, altimeter, and verti-cal speed indicator (VSI), which can help determinewhether or not the pitch attitude is correct. If gainingor losing altitude, the pitch attitude should beadjusted in relation to the horizon, and then thealtimeter and VSI rechecked to determine if altitudeis being maintained.

Figure 3-11. Visual reference for angle of bank.

RIGHT WRONG

Figure 3-13. Parallax view.

Figure 3-12. Right and wrong posture while seated in theairplane.

Ch 03.qxd 7/13/04 11:08 AM Page 3-11

3-12

During all turns, the ailerons, rudder, and elevator areused to correct minor variations in pitch and bank justas they are in straight-and-level flight.

The rollout from a turn is similar to the roll-in exceptthe flight controls are applied in the opposite direction.Aileron and rudder are applied in the direction of therollout or toward the high wing. As the angle of bankdecreases, the elevator pressure should be relaxed asnecessary to maintain altitude.

Since the airplane will continue turning as long as thereis any bank, the rollout must be started before reachingthe desired heading. The amount of lead required to rollout on the desired heading will depend on the degree ofbank used in the turn. Normally, the lead is one-half thedegrees of bank. For example, if the bank is 30°, lead therollout by 15°. As the wings become level, the controlpressures should be smoothly relaxed so that the controlsare neutralized as the airplane returns to straight-and-level flight. As the rollout is being completed, attentionshould be given to outside visual references, as well asthe attitude and heading indicators to determine that thewings are being leveled and the turn stopped.

Instruction in level turns should begin with mediumturns, so that the student has an opportunity to graspthe fundamentals of turning flight without havingto deal with overbanking tendency, or the inherentstability of the airplane attempting to level thewings. The instructor should not ask the student toroll the airplane from bank to bank, but to changeits attitude from level to bank, bank to level, and soon with a slight pause at the termination of eachphase. This pause allows the airplane to free itselffrom the effects of any misuse of the controls andassures a correct start for the next turn. Duringthese exercises, the idea of control forces, ratherthan movement, should be emphasized by pointingout the resistance of the controls to varying forcesapplied to them. The beginning student should beencouraged to use the rudder freely. Skidding in thisphase indicates positive control use, and may beeasily corrected later. The use of too little rudder, orrudder use in the wrong direction at this stage oftraining, on the other hand, indicates a lack ofproper conception of coordination.

In practicing turns, the action of the airplane’s nosewill show any error in coordination of the controls.Often, during the entry or recovery from a bank, thenose will describe a vertical arc above or below thehorizon, and then remain in proper position after thebank is established. This is the result of lack of timingand coordination of forces on the elevator and ruddercontrols during the entry and recovery. It indicates thatthe student has a knowledge of correct turns, but thatentry and recovery techniques are in error.

Because the elevator and ailerons are on one control,and pressures on both are executed simultaneously, thebeginning pilot is often apt to continue pressure on oneof these unintentionally when force on the other onlyis intended. This is particularly true in left-hand turns,because the position of the hands makes correctmovements slightly awkward at first. This is some-times responsible for the habit of climbing slightly inright-hand turns and diving slightly in left-handturns. This results from many factors, including theunequal rudder pressures required to the right and tothe left when turning, due to the torque effect.

The tendency to climb in right-hand turns and descendin left-hand turns is also prevalent in airplanes havingside-by-side cockpit seating. In this case, it is due tothe pilot’s being seated to one side of the longitudinalaxis about which the airplane rolls. This makes thenose appear to rise during a correctly executed left turnand to descend during a correctly executed right turn.An attempt to keep the nose on the same apparent levelwill cause climbing in right turns and diving in leftturns.

Excellent coordination and timing of all the controls inturning requires much practice. It is essential that thiscoordination be developed, because it is the very basisof this fundamental flight maneuver.

If the body is properly relaxed, it will act as a pendu-lum and may be swayed by any force acting on it.During a skid, it will be swayed away from the turn,and during a slip, toward the inside of the turn. Thesame effects will be noted in tendencies to slide on theseat. As the “feel” of flying develops, the properlydirected student will become highly sensitive to thislast tendency and will be able to detect the presenceof, or even the approach of, a slip or skid long beforeany other indication is present.

Common errors in the performance of level turns are:

• Failure to adequately clear the area before begin-ning the turn.

• Attempting to execute the turn solely by instru-ment reference.

• Attempting to sit up straight, in relation to theground, during a turn, rather than riding with theairplane.

• Insufficient feel for the airplane as evidenced bythe inability to detect slips/skids without referenceto flight instruments.

• Attempting to maintain a constant bank angle byreferencing the “cant” of the airplane’s nose.

Ch 03.qxd 7/13/04 11:08 AM Page 3-12

3-13

• Fixating on the nose reference while excludingwingtip reference.

• “Ground shyness”—making “flat turns” (skid-ding) while operating at low altitudes in a con-scious or subconscious effort to avoid bankingclose to the ground.

• Holding rudder in the turn.

• Gaining proficiency in turns in only one direction(usually the left).

• Failure to coordinate the use of throttle with othercontrols.

• Altitude gain/loss during the turn.

CLIMBS AND CLIMBING TURNSWhen an airplane enters a climb, it changes its flight-path from level flight to an inclined plane or climbattitude. In a climb, weight no longer acts in a direc-tion perpendicular to the flightpath. It acts in a rear-ward direction. This causes an increase in total dragrequiring an increase in thrust (power) to balance theforces. An airplane can only sustain a climb anglewhen there is sufficient thrust to offset increased drag;therefore, climb is limited by the thrust available.

Like other maneuvers, climbs should be performedusing outside visual references and flight instruments.It is important that the pilot know the engine powersettings and pitch attitudes that will produce the fol-lowing conditions of climb.

NORMAL CLIMB—Normal climb is performed atan airspeed recommended by the airplane manufac-turer. Normal climb speed is generally somewhathigher than the airplane’s best rate of climb. The addi-tional airspeed provides better engine cooling, easiercontrol, and better visibility over the nose. Normal

climb is sometimes referred to as “cruise climb.”Complex or high performance airplanes may have aspecified cruise climb in addition to normal climb.

BEST RATE OF CLIMB—Best rate of climb (VY) isperformed at an airspeed where the most excess poweris available over that required for level flight. Thiscondition of climb will produce the most gain in alti-tude in the least amount of time (maximum rate ofclimb in feet per minute). The best rate of climb madeat full allowable power is a maximum climb. It mustbe fully understood that attempts to obtain moreclimb performance than the airplane is capable of byincreasing pitch attitude will result in a decrease inthe rate of altitude gain.

BEST ANGLE OF CLIMB—Best angle of climb(VX) is performed at an airspeed that will produce themost altitude gain in a given distance. Best angle-of-climb airspeed (VX) is considerably lower than bestrate of climb (VY), and is the airspeed where the mostexcess thrust is available over that required for levelflight. The best angle of climb will result in a steeperclimb path, although the airplane will take longer toreach the same altitude than it would at best rate ofclimb. The best angle of climb, therefore, is used inclearing obstacles after takeoff. [Figure 3-14]

It should be noted that, as altitude increases, the speedfor best angle of climb increases, and the speed for bestrate of climb decreases. The point at which these twospeeds meet is the absolute ceiling of the airplane.[Figure 3-15 on next page]

A straight climb is entered by gently increasing pitchattitude to a predetermined level using back-elevatorpressure, and simultaneously increasing engine powerto the climb power setting. Due to an increase indownwash over the horizontal stabilizer as power isapplied, the airplane’s nose will tend to immediatelybegin to rise of its own accord to an attitude higher than

Best angle-of-climb airspeed (Vx)

gives the greatest altitude gain in the

shortest horizontal distance.

Best rate-of-climb airspeed (Vy)

gives the greatest altitude gain

in the shortest time.

Figure 3-14. Best angle of climb vs. best rate of climb.

Ch 03.qxd 7/13/04 11:08 AM Page 3-13

3-14

that at which it would stabilize. The pilot must be pre-pared for this.

As a climb is started, the airspeed will gradually dimin-ish. This reduction in airspeed is gradual because ofthe initial momentum of the airplane. The thrustrequired to maintain straight-and-level flight at a givenairspeed is not sufficient to maintain the same airspeedin a climb. Climbing flight requires more power thanflying level because of the increased drag caused bygravity acting rearward. Therefore, power must beadvanced to a higher power setting to offset theincreased drag.

The propeller effects at climb power are a primary fac-tor. This is because airspeed is significantly slowerthan at cruising speed, and the airplane’s angle ofattack is significantly greater. Under these conditions,torque and asymmetrical loading of the propeller willcause the airplane to roll and yaw to the left. Tocounteract this, the right rudder must be used.

During the early practice of climbs and climbing turns,this may make coordination of the controls seem awk-ward (left climbing turn holding right rudder), but aftera little practice this correction for propeller effects willbecome instinctive.

Trim is also a very important consideration during aclimb. After the climb has been established, the air-plane should be trimmed to relieve all pressures fromthe flight controls. If changes are made in the pitch atti-tude, power, or airspeed, the airplane should beretrimmed in order to relieve control pressures.

When performing a climb, the power should beadvanced to the climb power recommended by themanufacturer. If the airplane is equipped with a con-trollable-pitch propeller, it will have not only anengine tachometer, but also a manifold pressure gauge.Normally, the flaps and landing gear (if retractable)should be in the retracted position to reduce drag.

As the airplane gains altitude during a climb, the man-ifold pressure gauge (if equipped) will indicate a lossin manifold pressure (power). This is because the samevolume of air going into the engine’s induction systemgradually decreases in density as altitude increases.When the volume of air in the manifold decreases, itcauses a loss of power. This will occur at the rate ofapproximately 1-inch of manifold pressure for each1,000-foot gain in altitude. During prolonged climbs,the throttle must be continually advanced, if constantpower is to be maintained.

To enter the climb, simultaneously advance the throttleand apply back-elevator pressure to raise the nose of theairplane to the proper position in relation to the horizon.As power is increased, the airplane’s nose will rise dueto increased download on the stabilizer. This is causedby increased slipstream. As the pitch attitude increasesand the airspeed decreases, progressively more rightrudder must be applied to compensate for propellereffects and to hold a constant heading.

After the climb is established, back-elevator pressuremust be maintained to keep the pitch attitude constant.As the airspeed decreases, the elevators will try toreturn to their neutral or streamlined position, and theairplane’s nose will tend to lower. Nose-up elevatortrim should be used to compensate for this so that thepitch attitude can be maintained without holding back-elevator pressure. Throughout the climb, since thepower is fixed at the climb power setting, the airspeedis controlled by the use of elevator.

A cross-check of the airspeed indicator, attitude indi-cator, and the position of the airplane’s nose in relationto the horizon will determine if the pitch attitude iscorrect. At the same time, a constant heading shouldbe held with the wings level if a straight climb is beingperformed, or a constant angle of bank and rate of turnif a climbing turn is being performed. [Figure 3-16]

To return to straight-and-level flight from a climb, it isnecessary to initiate the level-off at approximately 10percent of the rate of climb. For example, if the airplaneis climbing at 500 feet per minute (f.p.m.), leveling offshould start 50 feet below the desired altitude. The nosemust be lowered gradually because a loss of altitudewill result if the pitch attitude is changed to the levelflight position without allowing the airspeed to increaseproportionately.

Absolute Ceiling

Service Ceiling

Figure 3-15. Absolute ceiling.

Ch 03.qxd 7/13/04 11:08 AM Page 3-14

3-15

After the airplane is established in level flight at aconstant altitude, climb power should be retainedtemporarily so that the airplane will accelerate to thecruise airspeed more rapidly. When the speed reachesthe desired cruise speed, the throttle setting and thepropeller control (if equipped) should be set to thecruise power setting and the airplane trimmed. Afterallowing time for engine temperatures to stabilize,adjust the mixture control as required.

In the performance of climbing turns, the followingfactors should be considered.

• With a constant power setting, the same pitch atti-tude and airspeed cannot be maintained in a bankas in a straight climb due to the increase in the totallift required.

• The degree of bank should not be too steep. Asteep bank significantly decreases the rate ofclimb. The bank should always remain constant.

• It is necessary to maintain a constant airspeed andconstant rate of turn in both right and left turns.The coordination of all flight controls is a primaryfactor.

• At a constant power setting, the airplane will climbat a slightly shallower climb angle because someof the lift is being used to turn the airplane.

• Attention should be diverted from fixation on theairplane’s nose and divided equally among insideand outside references.

There are two ways to establish a climbing turn. Eitherestablish a straight climb and then turn, or enter theclimb and turn simultaneously. Climbing turns shouldbe used when climbing to the local practice area.Climbing turns allow better visual scanning, and it iseasier for other pilots to see a turning aircraft.

In any turn, the loss of vertical lift and increasedinduced drag, due to increased angle of attack,

becomes greater as the angle of bank is increased. Soshallow turns should be used to maintain an efficientrate of climb.

All the factors that affect the airplane during level(constant altitude) turns will affect it during climbingturns or any other training maneuver. It will be notedthat because of the low airspeed, aileron drag (adverseyaw) will have a more prominent effect than it did instraight-and-level flight and more rudder pressure willhave to be blended with aileron pressure to keep theairplane in coordinated flight during changes in bankangle. Additional elevator back pressure and trim willalso have to be used to compensate for centrifugalforce, for the loss of vertical lift, and to keep pitch atti-tude constant.

During climbing turns, as in any turn, the loss of verti-cal lift and induced drag due to increased angle ofattack becomes greater as the angle of bank isincreased, so shallow turns should be used to maintainan efficient rate of climb. If a medium or steep bankedturn is used, climb performance will be degraded.

Common errors in the performance of climbs andclimbing turns are:

• Attempting to establish climb pitch attitude by ref-erencing the airspeed indicator, resulting in “chas-ing” the airspeed.

• Applying elevator pressure too aggressively,resulting in an excessive climb angle.

• Applying elevator pressure too aggressively dur-ing level-off resulting in negative “G” forces.

• Inadequate or inappropriate rudder pressure dur-ing climbing turns.

• Allowing the airplane to yaw in straight climbs,usually due to inadequate right rudder pressure.

• Fixation on the nose during straight climbs, result-ing in climbing with one wing low.

• Failure to initiate a climbing turn properly with useof rudder and elevators, resulting in little turn, butrather a climb with one wing low.

• Improper coordination resulting in a slip whichcounteracts the effect of the climb, resulting in lit-tle or no altitude gain.

• Inability to keep pitch and bank attitude constantduring climbing turns.

• Attempting to exceed the airplane’s climb capability.

DESCENTS AND DESCENDING TURNSWhen an airplane enters a descent, it changes its flight-path from level to an inclined plane. It is important that

Figure 3-16. Climb indications.

Ch 03.qxd 7/13/04 11:08 AM Page 3-15

3-16

the pilot know the power settings and pitch attitudesthat will produce the following conditions of descent.

PARTIAL POWER DESCENT—The normalmethod of losing altitude is to descend with partialpower. This is often termed “cruise” or “enroute”descent. The airspeed and power setting recommendedby the airplane manufacturer for prolonged descentshould be used. The target descent rate should be 400 –500 f.p.m. The airspeed may vary from cruise airspeedto that used on the downwind leg of the landing pat-tern. But the wide range of possible airspeeds shouldnot be interpreted to permit erratic pitch changes. Thedesired airspeed, pitch attitude, and power combina-tion should be preselected and kept constant.

DESCENT AT MINIMUM SAFE AIRSPEED—Aminimum safe airspeed descent is a nose-high, powerassisted descent condition principally used for clearingobstacles during a landing approach to a short runway.The airspeed used for this descent condition is recom-mended by the airplane manufacturer and normally isno greater than 1.3 VSO. Some characteristics of theminimum safe airspeed descent are a steeper than nor-mal descent angle, and the excessive power that maybe required to produce acceleration at low airspeedshould “mushing” and/or an excessive rate of descentbe allowed to develop.

GLIDES—A glide is a basic maneuver in which theairplane loses altitude in a controlled descent with littleor no engine power; forward motion is maintained bygravity pulling the airplane along an inclined path andthe descent rate is controlled by the pilot balancing theforces of gravity and lift.

Although glides are directly related to the practice ofpower-off accuracy landings, they have a specificoperational purpose in normal landing approaches, andforced landings after engine failure. Therefore, it isnecessary that they be performed more subconsciouslythan other maneuvers because most of the time duringtheir execution, the pilot will be giving full attention todetails other than the mechanics of performing themaneuver. Since glides are usually performed rela-tively close to the ground, accuracy of their executionand the formation of proper technique and habits are ofspecial importance.

Because the application of controls is somewhat dif-ferent in glides than in power-on descents, glidingmaneuvers require the perfection of a techniquesomewhat different from that required for ordinarypower-on maneuvers. This control difference iscaused primarily by two factors—the absence of theusual propeller slipstream, and the difference in therelative effectiveness of the various control surfacesat slow speeds.

The glide ratio of an airplane is the distance the air-plane will, with power off, travel forward in relation tothe altitude it loses. For instance, if an airplane travels10,000 feet forward while descending 1,000 feet, itsglide ratio is said to be 10 to 1.

The glide ratio is affected by all four fundamentalforces that act on an airplane (weight, lift, drag, andthrust). If all factors affecting the airplane are constant,the glide ratio will be constant. Although the effect ofwind will not be covered in this section, it is a veryprominent force acting on the gliding distance of theairplane in relationship to its movement over theground. With a tailwind, the airplane will glide fartherbecause of the higher groundspeed. Conversely, with aheadwind the airplane will not glide as far because ofthe slower groundspeed.

Variations in weight do not affect the glide angle pro-vided the pilot uses the correct airspeed. Since it is thelift over drag (L/D) ratio that determines the distance theairplane can glide, weight will not affect the distance.The glide ratio is based only on the relationship of theaerodynamic forces acting on the airplane. The onlyeffect weight has is to vary the time the airplane willglide. The heavier the airplane the higher the airspeedmust be to obtain the same glide ratio. For example, iftwo airplanes having the same L/D ratio, but differentweights, start a glide from the same altitude, the heavierairplane gliding at a higher airspeed will arrive at thesame touchdown point in a shorter time. Both airplaneswill cover the same distance, only the lighter airplanewill take a longer time.

Under various flight conditions, the drag factor maychange through the operation of the landing gearand/or flaps. When the landing gear or the flaps areextended, drag increases and the airspeed willdecrease unless the pitch attitude is lowered. As thepitch is lowered, the glidepath steepens and reducesthe distance traveled. With the power off, a wind-milling propeller also creates considerable drag,thereby retarding the airplane’s forward movement.

Although the propeller thrust of the airplane is nor-mally dependent on the power output of the engine,the throttle is in the closed position during a glide sothe thrust is constant. Since power is not used during aglide or power-off approach, the pitch attitude must beadjusted as necessary to maintain a constant airspeed.

The best speed for the glide is one at which the air-plane will travel the greatest forward distance for agiven loss of altitude in still air. This best glide speedcorresponds to an angle of attack resulting in the leastdrag on the airplane and giving the best lift-to-dragratio (L/DMAX). [Figure 3-17]

Ch 03.qxd 7/13/04 11:08 AM Page 3-16

3-17

Any change in the gliding airspeed will result in a pro-portionate change in glide ratio. Any speed, other thanthe best glide speed, results in more drag. Therefore, asthe glide airspeed is reduced or increased from theoptimum or best glide speed, the glide ratio is alsochanged. When descending at a speed below the bestglide speed, induced drag increases. When descendingat a speed above best glide speed, parasite dragincreases. In either case, the rate of descent willincrease. [Figure 3-18]

This leads to a cardinal rule of airplane flying that astudent pilot must understand and appreciate: The pilotmust never attempt to “stretch” a glide by applyingback-elevator pressure and reducing the airspeedbelow the airplane’s recommended best glide speed.Attempts to stretch a glide will invariably result in anincrease in the rate and angle of descent and may pre-cipitate an inadvertent stall.

To enter a glide, the pilot should close the throttle andadvance the propeller (if so equipped) to low pitch(high r.p.m.). A constant altitude should be held withback pressure on the elevator control until the airspeeddecreases to the recommended glide speed. Due to adecrease in downwash over the horizontal stabilizer aspower is reduced, the airplane’s nose will tend toimmediately begin to lower of its own accord to an atti-

tude lower than that at which it would stabilize. Thepilot must be prepared for this. To keep pitch attitudeconstant after a power change, the pilot must coun-teract the immediate trim change. If the pitch attitudeis allowed to decrease during glide entry, excessspeed will be carried into the glide and retard theattainment of the correct glide angle and airspeed.Speed should be allowed to dissipate before the pitchattitude is decreased. This point is particularlyimportant in so-called clean airplanes as they arevery slow to lose their speed and any slight deviationof the nose downwards results in an immediateincrease in airspeed. Once the airspeed has dissi-pated to normal or best glide speed, the pitch attitudeshould be allowed to decrease to maintain that speed.This should be done with reference to the horizon.When the speed has stabilized, the airplane shouldbe retrimmed for “hands off” flight.

When the approximate gliding pitch attitude isestablished, the airspeed indicator should bechecked. If the airspeed is higher than the recom-mended speed, the pitch attitude is too low, and ifthe airspeed is less than recommended, the pitchattitude is too high; therefore, the pitch attitudeshould be readjusted accordingly referencing thehorizon. After the adjustment has been made, theairplane should be retrimmed so that it will maintainthis attitude without the need to hold pressure on theelevator control. The principles of attitude flyingrequire that the proper flight attitude be establishedusing outside visual references first, then using theflight instruments as a secondary check. It is a goodpractice to always retrim the airplane after eachpitch adjustment.

A stabilized power-off descent at the best glide speedis often referred to as a normal glide. The flightinstructor should demonstrate a normal glide, anddirect the student pilot to memorize the airplane’sangle and speed by visually checking the airplane’sattitude with reference to the horizon, and noting thepitch of the sound made by the air passing over thestructure, the pressure on the controls, and the feel of

Incr

easi

ng L

ift-t

o-D

rag

Rat

io

Increasing Angle of Attack

L/Dmax

Figure 3-17. L/DMAX.

Best Glide Speed

Too Fast

Too Slow

Figure 3-18. Best glide speed provides the greatest forward distance for a given loss of altitude.

Ch 03.qxd 7/13/04 11:08 AM Page 3-17

3-18

the airplane. Due to lack of experience, the beginningstudent may be unable to recognize slight variationsof speed and angle of bank immediately by vision orby the pressure required on the controls. Hearing willprobably be the indicator that will be the most easilyused at first. The instructor should, therefore, be cer-tain that the student understands that an increase inthe pitch of sound denotes increasing speed, while adecrease in pitch denotes less speed. When such anindication is received, the student should consciouslyapply the other two means of perception so as toestablish the proper relationship. The student pilotmust use all three elements consciously until theybecome habits, and must be alert when attention isdiverted from the attitude of the airplane and beresponsive to any warning given by a variation in thefeel of the airplane or controls, or by a change in thepitch of the sound.

After a good comprehension of the normal glide isattained, the student pilot should be instructed in the dif-ferences in the results of normal and “abnormal” glides.Abnormal glides being those conducted at speeds otherthan the normal best glide speed. Pilots who do notacquire an understanding and appreciation of thesedifferences will experience difficulties with accuracylandings, which are comparatively simple if thefundamentals of the glide are thoroughly understood.

Too fast a glide during the approach for landinginvariably results in floating over the ground forvarying distances, or even overshooting, while tooslow a glide causes undershooting, flat approaches,and hard touchdowns. A pilot without the ability torecognize a normal glide will not be able to judgewhere the airplane will go, or can be made to go, inan emergency. Whereas, in a normal glide, the flight-path may be sighted to the spot on the ground onwhich the airplane will land. This cannot be done inany abnormal glide.

GLIDING TURNS—The action of the controlsystem is somewhat different in a glide than withpower, making gliding maneuvers stand in a class bythemselves and require the perfection of a techniquedifferent from that required for ordinary powermaneuvers. The control difference is caused mainly bytwo factors—the absence of the usual slipstream, andthe difference or relative effectiveness of the variouscontrol surfaces at various speeds and particularly atreduced speed. The latter factor has its effectexaggerated by the first, and makes the task ofcoordination even more difficult for the inexperiencedpilot. These principles should be thoroughly explainedin order that the student may be alert to the necessarydifferences in coordination.

After a feel for the airplane and control touch havebeen developed, the necessary compensation will be

automatic; but while any mechanical tendency exists,the student will have difficulty executing gliding turns,particularly when making a practical application ofthem in attempting accuracy landings.

Three elements in gliding turns which tend to force thenose down and increase glide speed are:

• Decrease in effective lift due to the direction ofthe lifting force being at an angle to the pull ofgravity.

• The use of the rudder acting as it does in the entryto a power turn.

• The normal stability and inherent characteristicsof the airplane to nose down with the power off.

These three factors make it necessary to use more backpressure on the elevator than is required for a straightglide or a power turn and, therefore, have a greatereffect on the relationship of control coordination.

When recovery is being made from a gliding turn, theforce on the elevator control which was applied duringthe turn must be decreased or the nose will come uptoo high and considerable speed will be lost. This errorwill require considerable attention and conscious con-trol adjustment before the normal glide can again beresumed.

In order to maintain the most efficient or normal glidein a turn, more altitude must be sacrificed than in astraight glide since this is the only way speed can bemaintained without power. Turning in a glidedecreases the performance of the airplane to an evengreater extent than a normal turn with power.

Still another factor is the difference in rudder action inturns with and without power. In power turns it isrequired that the desired recovery point be anticipated inthe use of controls and that considerably more pressurethan usual be exerted on the rudder. In the recovery froma gliding turn, the same rudder action takes place butwithout as much pressure being necessary. The actualdisplacement of the rudder is approximately the same,but it seems to be less in a glide because the resistance topressure is so much less due to the absence of the pro-peller slipstream. This often results in a much greaterapplication of rudder through a greater range than is real-ized, resulting in an abrupt stoppage of the turn when therudder is applied for recovery. This factor is particularlyimportant during landing practice since the studentalmost invariably recovers from the last turn too soonand may enter a cross-control condition trying to correctthe landing with the rudder alone. This results in landingfrom a skid that is too easily mistaken for drift.

Ch 03.qxd 7/13/04 11:08 AM Page 3-18

3-19

There is another danger in excessive rudder use duringgliding turns. As the airplane skids, the bank willincrease. This often alarms the beginning pilot when itoccurs close to the ground, and the pilot may respondby applying aileron pressure toward the outside of theturn to stop the bank. At the same time, the rudderforces the nose down and the pilot may apply back-ele-vator pressure to hold it up. If allowed to progress, thissituation may result in a fully developed cross-controlcondition. A stall in this situation will almost certainlyresult in a spin.

The level-off from a glide must be started beforereaching the desired altitude because of the airplane’sdownward inertia. The amount of lead depends on therate of descent and the pilot’s control technique. Withtoo little lead, there will be a tendency to descendbelow the selected altitude. For example, assuming a500-foot per minute rate of descent, the altitude mustbe led by 100 – 150 feet to level off at an airspeedhigher than the glide speed. At the lead point, powershould be increased to the appropriate level flightcruise setting so the desired airspeed will be attainedat the desired altitude. The nose tends to rise as bothairspeed and downwash on the tail section increase.The pilot must be prepared for this and smoothly con-trol the pitch attitude to attain level flight attitude sothat the level-off is completed at the desired altitude.

Particular attention should be paid to the action of theairplane’s nose when recovering (and entering) glidingturns. The nose must not be allowed to describe an arcwith relation to the horizon, and particularly it mustnot be allowed to come up during recovery from turns,which require a constant variation of the relative pres-sures on the different controls.

Common errors in the performance of descents anddescending turns are:

• Failure to adequately clear the area.

• Inadequate back-elevator control during glideentry resulting in too steep a glide.

• Failure to slow the airplane to approximate glidespeed prior to lowering pitch attitude.

• Attempting to establish/maintain a normal glidesolely by reference to flight instruments.

• Inability to sense changes in airspeed throughsound and feel.

• Inability to stabilize the glide (chasing the airspeedindicator).

• Attempting to “stretch” the glide by applyingback-elevator pressure.

• Skidding or slipping during gliding turns due toinadequate appreciation of the difference in rudderaction as opposed to turns with power.

• Failure to lower pitch attitude during gliding turnentry resulting in a decrease in airspeed.

• Excessive rudder pressure during recovery fromgliding turns.

• Inadequate pitch control during recovery fromstraight glides.

• “Ground shyness”—resulting in cross-controllingduring gliding turns near the ground.

• Failure to maintain constant bank angle duringgliding turns.

PITCH AND POWERNo discussion of climbs and descents would becomplete without touching on the question of whatcontrols altitude and what controls airspeed. Thepilot must understand the effects of both power andelevator control, working together, during differentconditions of flight. The closest one can come to aformula for determining airspeed/altitude controlthat is valid under all circumstances is a basic prin-ciple of attitude flying which states:

“At any pitch attitude, the amount of power usedwill determine whether the airplane will climb,descend, or remain level at that attitude.”

Through a wide range of nose-low attitudes, a descentis the only possible condition of flight. The addition ofpower at these attitudes will only result in a greater rateof descent at a faster airspeed.

Through a range of attitudes from very slightlynose-low to about 30° nose-up, a typical light air-plane can be made to climb, descend, or maintainaltitude depending on the power used. In about thelower third of this range, the airplane will descendat idle power without stalling. As pitch attitude isincreased, however, engine power will be requiredto prevent a stall. Even more power will be requiredto maintain altitude, and even more for a climb. At apitch attitude approaching 30° nose-up, all availablepower will provide only enough thrust to maintainaltitude. A slight increase in the steepness of climbor a slight decrease in power will produce a descent.From that point, the least inducement will result in astall.

Ch 03.qxd 7/13/04 11:08 AM Page 3-19

3-20

Ch 03.qxd 7/13/04 11:08 AM Page 3-20

4-1

INTRODUCTIONThe maintenance of lift and control of an airplane inflight requires a certain minimum airspeed. Thiscritical airspeed depends on certain factors, such asgross weight, load factors, and existing density altitude.The minimum speed below which further controlledflight is impossible is called the stalling speed. Animportant feature of pilot training is the developmentof the ability to estimate the margin of safety above thestalling speed. Also, the ability to determine thecharacteristic responses of any airplane at differentairspeeds is of great importance to the pilot. Thestudent pilot, therefore, must develop this awareness inorder to safely avoid stalls and to operate an airplanecorrectly and safely at slow airspeeds.

SLOW FLIGHTSlow flight could be thought of, by some, as a speedthat is less than cruise. In pilot training and testing,however, slow flight is broken down into two distinctelements: (1) the establishment, maintenance of, andmaneuvering of the airplane at airspeeds and inconfigurations appropriate to takeoffs, climbs,descents, landing approaches and go-arounds, and, (2)maneuvering at the slowest airspeed at which theairplane is capable of maintaining controlled flightwithout indications of a stall—usually 3 to 5 knotsabove stalling speed.

FLIGHT AT LESS THAN CRUISE AIRSPEEDSManeuvering during slow flight demonstrates the flightcharacteristics and degree of controllability of anairplane at less than cruise speeds. The ability todetermine the characteristic control responses at thelower airspeeds appropriate to takeoffs, departures,and landing approaches is a critical factor install awareness.

As airspeed decreases, control effectiveness decreasesdisproportionately. For instance, there may be a certainloss of effectiveness when the airspeed is reduced from30 to 20 m.p.h. above the stalling speed, but there willnormally be a much greater loss as the airspeed isfurther reduced to 10 m.p.h. above stalling. Theobjective of maneuvering during slow flight is todevelop the pilot’s sense of feel and ability to use thecontrols correctly, and to improve proficiency inperforming maneuvers that require slow airspeeds.

Maneuvering during slow flight should be performedusing both instrument indications and outside visualreference. Slow flight should be practiced from straightglides, straight-and-level flight, and from mediumbanked gliding and level flight turns. Slow flight atapproach speeds should include slowing the airplanesmoothly and promptly from cruising to approachspeeds without changes in altitude or heading, anddetermining and using appropriate power and trimsettings. Slow flight at approach speed should alsoinclude configuration changes, such as landing gearand flaps, while maintaining heading and altitude.

FLIGHT AT MINIMUM CONTROLLABLEAIRSPEEDThis maneuver demonstrates the flight characteristicsand degree of controllability of the airplane at itsminimum flying speed. By definition, the term “flightat minimum controllable airspeed” means a speed atwhich any further increase in angle of attack or loadfactor, or reduction in power will cause an immediatestall. Instruction in flight at minimum controllableairspeed should be introduced at reduced powersettings, with the airspeed sufficiently above the stall topermit maneuvering, but close enough to the stall tosense the characteristics of flight at very lowairspeed—which are sloppy controls, ragged responseto control inputs, and difficulty maintaining altitude.Maneuvering at minimum controllable airspeed shouldbe performed using both instrument indications andoutside visual reference. It is important that pilots formthe habit of frequent reference to the flight instruments,especially the airspeed indicator, while flying at verylow airspeeds. However, a “feel” for the airplane atvery low airspeeds must be developed to avoidinadvertent stalls and to operate the airplanewith precision.

To begin the maneuver, the throttle is graduallyreduced from cruising position. While the airspeed isdecreasing, the position of the nose in relation to thehorizon should be noted and should be raised asnecessary to maintain altitude.

When the airspeed reaches the maximum allowable forlanding gear operation, the landing gear (if equippedwith retractable gear) should be extended and all geardown checks performed. As the airspeed reaches themaximum allowable for flap operation, full flaps

Ch 04.qxd 5/7/04 6:46 AM Page 4-1

4-2

should be lowered and the pitch attitude adjusted tomaintain altitude. [Figure 4-1] Additional power willbe required as the speed further decreases to maintainthe airspeed just above a stall. As the speed decreasesfurther, the pilot should note the feel of the flightcontrols, especially the elevator. The pilot should alsonote the sound of the airflow as it falls off in tone level.

As airspeed is reduced, the flight controls become lesseffective and the normal nosedown tendency isreduced. The elevators become less responsive andcoarse control movements become necessary to retaincontrol of the airplane. The slipstream effect producesa strong yaw so the application of rudder is required tomaintain coordinated flight. The secondary effect ofapplied rudder is to induce a roll, so aileron is requiredto keep the wings level. This can result in flying withcrossed controls.

During these changing flight conditions, it is importantto retrim the airplane as often as necessary tocompensate for changes in control pressures. If theairplane has been trimmed for cruising speed, heavyaft control pressure will be needed on the elevators,making precise control impossible. If too much speedis lost, or too little power is used, further back pressureon the elevator control may result in a loss of altitudeor a stall. When the desired pitch attitude andminimum control airspeed have been established, it isimportant to continually cross-check the attitudeindicator, altimeter, and airspeed indicator, as well asoutside references to ensure that accurate control isbeing maintained.

The pilot should understand that when flying moreslowly than minimum drag speed (LD/MAX) theairplane will exhibit a characteristic known as “speedinstability.” If the airplane is disturbed by even theslightest turbulence, the airspeed will decrease. Asairspeed decreases, the total drag also increasesresulting in a further loss in airspeed. The total dragcontinues to rise and the speed continues to fall. Unlessmore power is applied and/or the nose is lowered,the speed will continue to decay right down to thestall. This is an extremely important factor in the

performance of slow flight. The pilot must understandthat, at speed less than minimum drag speed, theairspeed is unstable and will continue to decay ifallowed to do so.

When the attitude, airspeed, and power have beenstabilized in straight flight, turns should be practicedto determine the airplane’s controllability characteris-tics at this minimum speed. During the turns, powerand pitch attitude may need to be increased tomaintain the airspeed and altitude. The objective is toacquaint the pilot with the lack of maneuverability atminimum speeds, the danger of incipient stalls, andthe tendency of the airplane to stall as the bank isincreased. A stall may also occur as a result of abruptor rough control movements when flying at thiscritical airspeed.

Abruptly raising the flaps while at minimumcontrollable airspeed will result in lift suddenlybeing lost, causing the airplane to lose altitude orperhaps stall.

Once flight at minimum controllable airspeed is set upproperly for level flight, a descent or climb atminimum controllable airspeed can be established byadjusting the power as necessary to establish thedesired rate of descent or climb. The beginning pilotshould note the increased yawing tendency at mini-mum control airspeed at high power settings with flapsfully extended. In some airplanes, an attempt to climbat such a slow airspeed may result in a loss of altitude,even with maximum power applied.

Common errors in the performance of slow flight are:

• Failure to adequately clear the area.

• Inadequate back-elevator pressure as power isreduced, resulting in altitude loss.

• Excessive back-elevator pressure as power isreduced, resulting in a climb, followed by a rapidreduction in airspeed and “mushing.”

• Inadequate compensation for adverse yaw duringturns.

• Fixation on the airspeed indicator.

• Failure to anticipate changes in lift as flaps areextended or retracted.

• Inadequate power management.

• Inability to adequately divide attention betweenairplane control and orientation.

SLOW FLIGHT

Low airspeedHigh angle of attackHigh power settingMaintain altitude

Figure 4-1. Slow flight—Low airspeed, high angle of attack,high power, and constant altitude.

Ch 04.qxd 5/7/04 6:46 AM Page 4-2

4-3

STALLSA stall occurs when the smooth airflow over theairplane’s wing is disrupted, and the lift degeneratesrapidly. This is caused when the wing exceeds itscritical angle of attack. This can occur at any airspeed,in any attitude, with any power setting. [Figure 4-2]

The practice of stall recovery and the development ofawareness of stalls are of primary importance in pilottraining. The objectives in performing intentional stallsare to familiarize the pilot with the conditions thatproduce stalls, to assist in recognizing an approachingstall, and to develop the habit of taking promptpreventive or corrective action.

Intentional stalls should be performed at an altitudethat will provide adequate height above the ground forrecovery and return to normal level flight. Though itdepends on the degree to which a stall has progressed,most stalls require some loss of altitude duringrecovery. The longer it takes to recognize theapproaching stall, the more complete the stall is likelyto become, and the greater the loss of altitude tobe expected.

RECOGNITION OF STALLSPilots must recognize the flight conditions that areconducive to stalls and know how to apply thenecessary corrective action. They should learn torecognize an approaching stall by sight, sound, andfeel. The following cues may be useful in recognizingthe approaching stall.

• Vision is useful in detecting a stall condition bynoting the attitude of the airplane. This sense canonly be relied on when the stall is the result of anunusual attitude of the airplane. Since the airplanecan also be stalled from a normal attitude, visionin this instance would be of little help in detectingthe approaching stall.

• Hearing is also helpful in sensing a stall condition.In the case of fixed-pitch propeller airplanes in apower-on condition, a change in sound due to lossof revolutions per minute (r.p.m.) is particularlynoticeable. The lessening of the noise made by theair flowing along the airplane structure as airspeeddecreases is also quite noticeable, and when thestall is almost complete, vibration and incidentnoises often increase greatly.

• Kinesthesia, or the sensing of changes in directionor speed of motion, is probably the most importantand the best indicator to the trained andexperienced pilot. If this sensitivity is properlydeveloped, it will warn of a decrease in speedor the beginning of a settling or mushing ofthe airplane.

• Feel is an important sense in recognizing the onsetof a stall. The feeling of control pressures is veryimportant. As speed is reduced, the resistance topressures on the controls becomes progressivelyless. Pressures exerted on the controls tend tobecome movements of the control surfaces. The

-4 0 5 10 15 20Angle of Attack in Degrees

Coe

ffici

ent o

f Lift

(C

L)

2.0

1.5

1.0

.5

Figure 4-2. Critical angle of attack and stall.

Ch 04.qxd 5/7/04 6:46 AM Page 4-3

4-4

lag between these movements and the response ofthe airplane becomes greater, until in a completestall all controls can be moved with almost noresistance, and with little immediate effect on theairplane. Just before the stall occurs, buffeting,uncontrollable pitching, or vibrations may begin.

Several types of stall warning indicators have beendeveloped to warn pilots of an approaching stall. Theuse of such indicators is valuable and desirable, but thereason for practicing stalls is to learn to recognize stallswithout the benefit of warning devices.

FUNDAMENTALS OF STALL RECOVERYDuring the practice of intentional stalls, the realobjective is not to learn how to stall an airplane, but tolearn how to recognize an approaching stall and takeprompt corrective action. [Figure 4-3] Though therecovery actions must be taken in a coordinatedmanner, they are broken down into three actions herefor explanation purposes.

First, at the indication of a stall, the pitch attitude andangle of attack must be decreased positively and

immediately. Since the basic cause of a stall is alwaysan excessive angle of attack, the cause must first beeliminated by releasing the back-elevator pressure thatwas necessary to attain that angle of attack or bymoving the elevator control forward. This lowers thenose and returns the wing to an effective angle ofattack. The amount of elevator control pressure ormovement used depends on the design of the airplane,the severity of the stall, and the proximity of theground. In some airplanes, a moderate movement ofthe elevator control—perhaps slightly forward ofneutral—is enough, while in others a forcible push tothe full forward position may be required. Anexcessive negative load on the wings caused byexcessive forward movement of the elevator mayimpede, rather than hasten, the stall recovery. Theobject is to reduce the angle of attack but only enoughto allow the wing to regain lift.

Second, the maximum allowable power should beapplied to increase the airplane’s airspeed and assist inreducing the wing’s angle of attack. The throttleshould be promptly, but smoothly, advanced to themaximum allowable power. The flight instructor

Stall Recognition

• High angle of attack• Airframe buffeting or shaking• Warning horn or light• Loss of lift

Stall Recovery• Reduce angle of attack• Add power

Figure 4-3. Stall recognition and recovery.

Ch 04.qxd 5/7/04 6:47 AM Page 4-4

4-5

should emphasize, however, that power is not essentialfor a safe stall recovery if sufficient altitude isavailable. Reducing the angle of attack is the only wayof recovering from a stall regardless of the amount ofpower used.

Although stall recoveries should be practiced without,as well as with the use of power, in most actual stallsthe application of more power, if available, is anintegral part of the stall recovery. Usually, the greaterthe power applied, the less the loss of altitude.

Maximum allowable power applied at the instant of astall will usually not cause overspeeding of an engineequipped with a fixed-pitch propeller, due to the heavyair load imposed on the propeller at slow airspeeds.However, it will be necessary to reduce the power asairspeed is gained after the stall recovery so theairspeed will not become excessive. When performingintentional stalls, the tachometer indication shouldnever be allowed to exceed the red line (maximumallowable r.p.m.) marked on the instrument.

Third, straight-and-level flight should be regained withcoordinated use of all controls.

Practice in both power-on and power-off stalls isimportant because it simulates stall conditions thatcould occur during normal flight maneuvers. Forexample, the power-on stalls are practiced to showwhat could happen if the airplane were climbing at anexcessively nose-high attitude immediately aftertakeoff or during a climbing turn. The power-offturning stalls are practiced to show what could happenif the controls are improperly used during a turn fromthe base leg to the final approach. The power-offstraight-ahead stall simulates the attitude and flightcharacteristics of a particular airplane during the finalapproach and landing.

Usually, the first few practices should include onlyapproaches to stalls, with recovery initiated as soon asthe first buffeting or partial loss of control is noted. In

this way, the pilot can become familiar with theindications of an approaching stall without actuallystalling the airplane. Once the pilot becomescomfortable with this procedure, the airplane shouldbe slowed in such a manner that it stalls in as near alevel pitch attitude as is possible. The student pilotmust not be allowed to form the impression that in allcircumstances, a high pitch attitude is necessary toexceed the critical angle of attack, or that in allcircumstances, a level or near level pitch attitude isindicative of a low angle of attack. Recovery should bepracticed first without the addition of power, by merelyrelieving enough back-elevator pressure that the stallis broken and the airplane assumes a normal glideattitude. The instructor should also introduce thestudent to a secondary stall at this point. Stallrecoveries should then be practiced with the additionof power to determine how effective power will be inexecuting a safe recovery and minimizing altitude loss.

Stall accidents usually result from an inadvertent stallat a low altitude in which a recovery was notaccomplished prior to contact with the surface. As apreventive measure, stalls should be practiced at analtitude which will allow recovery no lower than 1,500feet AGL. To recover with a minimum loss of altituderequires a reduction in the angle of attack (loweringthe airplane’s pitch attitude), application of power, andtermination of the descent without entering another(secondary) stall.

USE OF AILERONS/RUDDER IN STALLRECOVERYDifferent types of airplanes have different stallcharacteristics. Most airplanes are designed so that thewings will stall progressively outward from the wingroots (where the wing attaches to the fuselage) to thewingtips. This is the result of designing the wings in amanner that the wingtips have less angle of incidencethan the wing roots. [Figure 4-4] Such a design featurecauses the wingtips to have a smaller angle of attackthan the wing roots during flight.

Figure 4-4. Wingtip washout.

Ch 04.qxd 5/7/04 6:47 AM Page 4-5

4-6

Exceeding the critical angle of attack causes a stall; thewing roots of an airplane will exceed the critical anglebefore the wingtips, and the wing roots will stall first.The wings are designed in this manner so that aileroncontrol will be available at high angles of attack (slowairspeed) and give the airplane more stable stallingcharacteristics.

When the airplane is in a stalled condition, thewingtips continue to provide some degree of lift, andthe ailerons still have some control effect. Duringrecovery from a stall, the return of lift begins at the tipsand progresses toward the roots. Thus, the ailerons canbe used to level the wings.

Using the ailerons requires finesse to avoid anaggravated stall condition. For example, if the rightwing dropped during the stall and excessive aileroncontrol were applied to the left to raise the wing, theaileron deflected downward (right wing) wouldproduce a greater angle of attack (and drag), andpossibly a more complete stall at the tip as the criticalangle of attack is exceeded. The increase in dragcreated by the high angle of attack on that wing mightcause the airplane to yaw in that direction. This adverseyaw could result in a spin unless directional controlwas maintained by rudder, and/or the aileron controlsufficiently reduced.

Even though excessive aileron pressure may have beenapplied, a spin will not occur if directional (yaw)control is maintained by timely application ofcoordinated rudder pressure. Therefore, it is importantthat the rudder be used properly during both the entryand the recovery from a stall. The primary use of therudder in stall recoveries is to counteract any tendencyof the airplane to yaw or slip. The correct recoverytechnique would be to decrease the pitch attitude byapplying forward-elevator pressure to break the stall,advancing the throttle to increase airspeed, andsimultaneously maintaining directional control withcoordinated use of the aileron and rudder.

STALL CHARACTERISTICSBecause of engineering design variations, the stallcharacteristics for all airplanes cannot be specificallydescribed; however, the similarities found in smallgeneral aviation training-type airplanes are noteworthyenough to be considered. It will be noted that thepower-on and power-off stall warning indications willbe different. The power-off stall will have lessnoticeable clues (buffeting, shaking) than thepower-on stall. In the power-off stall, the predominantclue can be the elevator control position (full up-elevator against the stops) and a high descent rate.When performing the power-on stall, the buffeting willlikely be the predominant clue that provides a positiveindication of the stall. For the purpose of airplane

certification, the stall warning may be furnished eitherthrough the inherent aerodynamic qualities of theairplane, or by a stall warning device that will give aclear distinguishable indication of the stall. Mostairplanes are equipped with a stall warning device.

The factors that affect the stalling characteristics of theairplane are balance, bank, pitch attitude, coordination,drag, and power. The pilot should learn the effect of thestall characteristics of the airplane being flown and theproper correction. It should be reemphasized that a stallcan occur at any airspeed, in any attitude, or at anypower setting, depending on the total number of factorsaffecting the particular airplane.

A number of factors may be induced as the result ofother factors. For example, when the airplane is in anose-high turning attitude, the angle of bank has atendency to increase. This occurs because with theairspeed decreasing, the airplane begins flying in asmaller and smaller arc. Since the outer wing ismoving in a larger radius and traveling faster than theinner wing, it has more lift and causes an overbankingtendency. At the same time, because of the decreasingairspeed and lift on both wings, the pitch attitude tendsto lower. In addition, since the airspeed is decreasingwhile the power setting remains constant, the effect oftorque becomes more prominent, causing the airplaneto yaw.

During the practice of power-on turning stalls, tocompensate for these factors and to maintain aconstant flight attitude until the stall occurs, aileronpressure must be continually adjusted to keep the bankattitude constant. At the same time, back-elevatorpressure must be continually increased to maintain thepitch attitude, as well as right rudder pressureincreased to keep the ball centered and to preventadverse yaw from changing the turn rate. If the bank isallowed to become too steep, the vertical componentof lift decreases and makes it even more difficult tomaintain a constant pitch attitude.

Whenever practicing turning stalls, a constant pitchand bank attitude should be maintained until the stalloccurs. Whatever control pressures are necessaryshould be applied even though the controls appear tobe crossed (aileron pressure in one direction, rudderpressure in the opposite direction). During the entry toa power-on turning stall to the right, in particular, thecontrols will be crossed to some extent. This is due toright rudder pressure being used to overcome torqueand left aileron pressure being used to prevent thebank from increasing.

APPROACHES TO STALLS (IMMINENTSTALLS)—POWER-ON OR POWER-OFFAn imminent stall is one in which the airplane isapproaching a stall but is not allowed to completely

Ch 04.qxd 5/7/04 6:47 AM Page 4-6

4-7

stall. This stall maneuver is primarily for practice inretaining (or regaining) full control of the airplaneimmediately upon recognizing that it is almost in a stallor that a stall is likely to occur if timely preventiveaction is not taken.

The practice of these stalls is of particular value indeveloping the pilot’s sense of feel for executingmaneuvers in which maximum airplane performanceis required. These maneuvers require flight with theairplane approaching a stall, and recovery initiatedbefore a stall occurs. As in all maneuvers that involvesignificant changes in altitude or direction, the pilotmust ensure that the area is clear of other air trafficbefore executing the maneuver.

These stalls may be entered and performed in theattitudes and with the same configuration of the basicfull stalls or other maneuvers described in this chapter.However, instead of allowing a complete stall, whenthe first buffeting or decay of control effectiveness isnoted, the angle of attack must be reduced immediatelyby releasing the back-elevator pressure and applyingwhatever additional power is necessary. Since theairplane will not be completely stalled, the pitchattitude needs to be decreased only to a point whereminimum controllable airspeed is attained or untiladequate control effectiveness is regained.

The pilot must promptly recognize the indication of astall and take timely, positive control action to preventa full stall. Performance is unsatisfactory if a full stalloccurs, if an excessively low pitch attitude is attained,or if the pilot fails to take timely action to avoidexcessive airspeed, excessive loss of altitude, or a spin.

FULL STALLS POWER-OFFThe practice of power-off stalls is usually performedwith normal landing approach conditions in simulation

of an accidental stall occurring during landingapproaches. Airplanes equipped with flaps and/orretractable landing gear should be in the landingconfiguration. Airspeed in excess of the normalapproach speed should not be carried into a stall entrysince it could result in an abnormally nose-highattitude. Before executing these practice stalls, thepilot must be sure the area is clear of other air traffic.

After extending the landing gear, applying carburetorheat (if applicable), and retarding the throttle to idle(or normal approach power), the airplane should beheld at a constant altitude in level flight until theairspeed decelerates to that of a normal approach. Theairplane should then be smoothly nosed down into thenormal approach attitude to maintain that airspeed.Wing flaps should be extended and pitch attitudeadjusted to maintain the airspeed.

When the approach attitude and airspeed havestabilized, the airplane’s nose should be smoothlyraised to an attitude that will induce a stall. Directionalcontrol should be maintained with the rudder, thewings held level by use of the ailerons, and a constant-pitch attitude maintained with the elevator until thestall occurs. The stall will be recognized by clues, suchas full up-elevator, high descent rate, uncontrollablenosedown pitching, and possible buffeting.

Recovering from the stall should be accomplished byreducing the angle of attack, releasing back-elevatorpressure, and advancing the throttle to maximumallowable power. Right rudder pressure is necessary toovercome the engine torque effects as power isadvanced and the nose is being lowered. [Figure 4-5]

The nose should be lowered as necessary to regainflying speed and returned to straight-and-level flight

Establish normal approach

Raise nose, maintain heading

When stall occurs, reduce angle of attack

and add full power.Raise flaps as recommended

As flying speed returns, stop descent and establish a climb

Climb at V , raise landing gear and

remaining flaps, trim

Y

Level off at desired altitude,set power and trim

Figure 4-5. Power-off stall and recovery.

Ch 04.qxd 5/7/04 6:47 AM Page 4-7

4-8

attitude. After establishing a positive rate of climb, theflaps and landing gear are retracted, as necessary, andwhen in level flight, the throttle should be returned tocruise power setting. After recovery is complete, a climbor go-around procedure should be initiated, as the situa-tion dictates, to assure a minimum loss of altitude.

Recovery from power-off stalls should also bepracticed from shallow banked turns to simulate aninadvertent stall during a turn from base leg to finalapproach. During the practice of these stalls, careshould be taken that the turn continues at a uniformrate until the complete stall occurs. If the power-offturn is not properly coordinated while approaching thestall, wallowing may result when the stall occurs. If theairplane is in a slip, the outer wing may stall first andwhip downward abruptly. This does not affect therecovery procedure in any way; the angle of attackmust be reduced, the heading maintained, and thewings leveled by coordinated use of the controls. Inthe practice of turning stalls, no attempt should bemade to stall the airplane on a predetermined heading.However, to simulate a turn from base to finalapproach, the stall normally should be made to occurwithin a heading change of approximately 90°.

After the stall occurs, the recovery should be madestraight ahead with minimum loss of altitude, andaccomplished in accordance with the recoveryprocedure discussed earlier.

Recoveries from power-off stalls should beaccomplished both with, and without, the addition ofpower, and may be initiated either just after the stalloccurs, or after the nose has pitched down through thelevel flight attitude.

FULL STALLS POWER-ONPower-on stall recoveries are practiced from straightclimbs, and climbing turns with 15 to 20° banks, tosimulate an accidental stall occurring during takeoffsand climbs. Airplanes equipped with flaps and/orretractable landing gear should normally be in thetakeoff configuration; however, power-on stalls shouldalso be practiced with the airplane in a cleanconfiguration (flaps and/or gear retracted) as indeparture and normal climbs.

After establishing the takeoff or climb configuration,the airplane should be slowed to the normal lift-offspeed while clearing the area for other air traffic.When the desired speed is attained, the power shouldbe set at takeoff power for the takeoff stall or therecommended climb power for the departure stallwhile establishing a climb attitude. The purpose ofreducing the airspeed to lift-off airspeed before thethrottle is advanced to the recommended setting is toavoid an excessively steep nose-up attitude for a longperiod before the airplane stalls.

After the climb attitude is established, the nose is thenbrought smoothly upward to an attitude obviouslyimpossible for the airplane to maintain and is held atthat attitude until the full stall occurs. In mostairplanes, after attaining the stalling attitude, theelevator control must be moved progressively furtherback as the airspeed decreases until, at the full stall, itwill have reached its limit and cannot be moved backany farther.

Recovery from the stall should be accomplished byimmediately reducing the angle of attack by positively

As flying speedreturns, stopdescent and

establish a climb

Climb at V , raise landing gear and

remaining flaps, trim

YLevel off at desiredaltitude, set power

and trim

Slow tolift-off speed,

maintain altitude

Set takeoff power,raise nose

When stall occurs,reduce angle ofattack and add

full power

Figure 4-6. Power-on stall.

Ch 04.qxd 5/7/04 6:47 AM Page 4-8

4-9

releasing back-elevator pressure and, in the case of adeparture stall, smoothly advancing the throttle tomaximum allowable power. In this case, since thethrottle is already at the climb power setting, the addi-tion of power will be relatively slight. [Figure 4-6]

The nose should be lowered as necessary to regainflying speed with the minimum loss of altitude andthen raised to climb attitude. Then, the airplane shouldbe returned to the normal straight-and-level flight atti-tude, and when in normal level flight, the throttleshould be returned to cruise power setting. The pilotmust recognize instantly when the stall has occurredand take prompt action to prevent a prolonged stalledcondition.

SECONDARY STALLThis stall is called a secondary stall since it may occurafter a recovery from a preceding stall. It is caused byattempting to hasten the completion of a stall recoverybefore the airplane has regained sufficient flyingspeed. [Figure 4-7] When this stall occurs, theback-elevator pressure should again be released just asin a normal stall recovery. When sufficient airspeedhas been regained, the airplane can then be returned tostraight-and-level flight.

This stall usually occurs when the pilot uses abruptcontrol input to return to straight-and-level flight aftera stall or spin recovery. It also occurs when the pilotfails to reduce the angle of attack sufficiently duringstall recovery by not lowering pitch attitudesufficiently, or by attempting to break the stall by usingpower only.

ACCELERATED STALLSThough the stalls just discussed normally occur at aspecific airspeed, the pilot must thoroughly understand

that all stalls result solely from attempts to fly atexcessively high angles of attack. During flight, theangle of attack of an airplane wing is determined by anumber of factors, the most important of which are theairspeed, the gross weight of the airplane, and the loadfactors imposed by maneuvering.

At the same gross weight, airplane configuration, andpower setting, a given airplane will consistently stall atthe same indicated airspeed if no acceleration isinvolved. The airplane will, however, stall at a higherindicated airspeed when excessive maneuvering loadsare imposed by steep turns, pull-ups, or other abruptchanges in its flightpath. Stalls entered from such flightsituations are called “accelerated maneuver stalls,” aterm, which has no reference to the airspeeds involved.

Stalls which result from abrupt maneuvers tend to bemore rapid, or severe, than the unaccelerated stalls, andbecause they occur at higher-than-normal airspeeds,and/or may occur at lower than anticipated pitchattitudes, they may be unexpected by an inexperiencedpilot. Failure to take immediate steps toward recoverywhen an accelerated stall occurs may resultin a complete loss of flight control, notably,power-on spins.

This stall should never be practiced with wing flaps inthe extended position due to the lower “G” loadlimitations in that configuration.

Accelerated maneuver stalls should not be performedin any airplane, which is prohibited from suchmaneuvers by its type certification restrictions orAirplane Flight Manual (AFM) and/or Pilot’sOperating Handbook (POH). If they are permitted,they should be performed with a bank ofapproximately 45°, and in no case at a speed greater

Initial stall

Incomplete or improperrecovery

Secondary stall

Figure 4-7. Secondary stall.

Ch 04.qxd 5/7/04 6:47 AM Page 4-9

4-10

than the airplane manufacturer’s recommendedairspeeds or the design maneuvering speed specifiedfor the airplane. The design maneuvering speed is themaximum speed at which the airplane can be stalled orfull available aerodynamic control will not exceed theairplane’s limit load factor. At or below this speed, theairplane will usually stall before the limit load factorcan be exceeded. Those speeds must not be exceededbecause of the extremely high structural loads that areimposed on the airplane, especially if there isturbulence. In most cases, these stalls should beperformed at no more than 1.2 times the normalstall speed.

The objective of demonstrating accelerated stalls is notto develop competency in setting up the stall, but ratherto learn how they may occur and to develop the abilityto recognize such stalls immediately, and to takeprompt, effective recovery action. It is important thatrecoveries are made at the first indication of a stall, orimmediately after the stall has fully developed; aprolonged stall condition should never be allowed.

An airplane will stall during a coordinated steep turnexactly as it does from straight flight, except that thepitching and rolling actions tend to be more sudden. Ifthe airplane is slipping toward the inside of the turn atthe time the stall occurs, it tends to roll rapidly towardthe outside of the turn as the nose pitches downbecause the outside wing stalls before the inside wing.If the airplane is skidding toward the outside of theturn, it will have a tendency to roll to the inside of theturn because the inside wing stalls first. If thecoordination of the turn at the time of the stall isaccurate, the airplane’s nose will pitch away from thepilot just as it does in a straight flight stall, since bothwings stall simultaneously.

An accelerated stall demonstration is entered byestablishing the desired flight attitude, then smoothly,firmly, and progressively increasing the angle of attackuntil a stall occurs. Because of the rapidly changingflight attitude, sudden stall entry, and possible loss ofaltitude, it is extremely vital that the area be clear ofother aircraft and the entry altitude be adequate for saferecovery.

This demonstration stall, as in all stalls, isaccomplished by exerting excessive back-elevatorpressure. Most frequently it would occur duringimproperly executed steep turns, stall and spinrecoveries, and pullouts from steep dives. Theobjectives are to determine the stall characteristics ofthe airplane and develop the ability to instinctivelyrecover at the onset of a stall at other-than-normal stallspeed or flight attitudes. An accelerated stall, althoughusually demonstrated in steep turns, may actually beencountered any time excessive back-elevator pressure

is applied and/or the angle of attack is increasedtoo rapidly.

From straight-and-level flight at maneuvering speedor less, the airplane should be rolled into a steep levelflight turn and back-elevator pressure graduallyapplied. After the turn and bank are established,back-elevator pressure should be smoothly andsteadily increased. The resulting apparent centrifugalforce will push the pilot’s body down in the seat,increase the wing loading, and decrease the airspeed.After the airspeed reaches the design maneuveringspeed or within 20 knots above the unaccelerated stallspeed, back-elevator pressure should be firmlyincreased until a definite stall occurs. These speedrestrictions must be observed to prevent exceeding theload limit of the airplane.

When the airplane stalls, recovery should be madepromptly, by releasing sufficient back-elevatorpressure and increasing power to reduce the angle ofattack. If an uncoordinated turn is made, one wing maytend to drop suddenly, causing the airplane to roll inthat direction. If this occurs, the excessive back-elevator pressure must be released, power added, andthe airplane returned to straight-and-level flight withcoordinated control pressure.

The pilot should recognize when the stall is imminentand take prompt action to prevent a completely stalledcondition. It is imperative that a prolonged stall,excessive airspeed, excessive loss of altitude, or spinbe avoided.

CROSS-CONTROL STALLThe objective of a cross-control stall demonstrationmaneuver is to show the effect of improper controltechnique and to emphasize the importance of usingcoordinated control pressures whenever making turns.This type of stall occurs with the controls crossed—aileron pressure applied in one direction and rudderpressure in the opposite direction.

In addition, when excessive back-elevator pressure isapplied, a cross-control stall may result. This is a stallthat is most apt to occur during a poorly planned andexecuted base-to-final approach turn, and often is theresult of overshooting the centerline of the runwayduring that turn. Normally, the proper action to correctfor overshooting the runway is to increase the rate ofturn by using coordinated aileron and rudder. At therelatively low altitude of a base-to-final approach turn,improperly trained pilots may be apprehensive ofsteepening the bank to increase the rate of turn, andrather than steepening the bank, they hold the bankconstant and attempt to increase the rate of turn byadding more rudder pressure in an effort to align itwith the runway.

Ch 04.qxd 5/7/04 6:47 AM Page 4-10

4-11

The addition of inside rudder pressure will cause thespeed of the outer wing to increase, therefore, creatinggreater lift on that wing. To keep that wing from risingand to maintain a constant angle of bank, oppositeaileron pressure needs to be applied. The added insiderudder pressure will also cause the nose to lower inrelation to the horizon. Consequently, additionalback-elevator pressure would be required to maintain aconstant-pitch attitude. The resulting condition is aturn with rudder applied in one direction, aileron in theopposite direction, and excessive back-elevatorpressure—a pronounced cross-control condition.

Since the airplane is in a skidding turn during thecross-control condition, the wing on the outside of theturn speeds up and produces more lift than the insidewing; thus, the airplane starts to increase its bank. Thedown aileron on the inside of the turn helps drag thatwing back, slowing it up and decreasing its lift, whichrequires more aileron application. This further causesthe airplane to roll. The roll may be so fast that it ispossible the bank will be vertical or past vertical beforeit can be stopped.

For the demonstration of the maneuver, it is importantthat it be entered at a safe altitude because of thepossible extreme nosedown attitude and loss ofaltitude that may result.

Before demonstrating this stall, the pilot should clearthe area for other air traffic while slowly retarding thethrottle. Then the landing gear (if retractable gear)should be lowered, the throttle closed, and the altitudemaintained until the airspeed approaches the normalglide speed. Because of the possibility of exceedingthe airplane’s limitations, flaps should not be extended.While the gliding attitude and airspeed are beingestablished, the airplane should be retrimmed. Whenthe glide is stabilized, the airplane should be rolled intoa medium-banked turn to simulate a final approachturn that would overshoot the centerline of the runway.

During the turn, excessive rudder pressure should beapplied in the direction of the turn but the bank heldconstant by applying opposite aileron pressure. At thesame time, increased back-elevator pressure isrequired to keep the nose from lowering.

All of these control pressures should be increased untilthe airplane stalls. When the stall occurs, recovery ismade by releasing the control pressures and increasingpower as necessary to recover.

In a cross-control stall, the airplane often stalls withlittle warning. The nose may pitch down, the insidewing may suddenly drop, and the airplane maycontinue to roll to an inverted position. This is usuallythe beginning of a spin. It is obvious that close to theground is no place to allow this to happen.

Recovery must be made before the airplane enters anabnormal attitude (vertical spiral or spin); it is a simplematter to return to straight-and-level flight bycoordinated use of the controls. The pilot must be ableto recognize when this stall is imminent and must takeimmediate action to prevent a completely stalledcondition. It is imperative that this type of stall notoccur during an actual approach to a landing, sincerecovery may be impossible prior to ground contactdue to the low altitude.

The flight instructor should be aware that during trafficpattern operations, any conditions that result inovershooting the turn from base leg to final approach,dramatically increases the possibility of anunintentional accelerated stall while the airplane is in across-control condition.

ELEVATOR TRIM STALLThe elevator trim stall maneuver shows what can hap-pen when full power is applied for a go-around andpositive control of the airplane is not maintained.[Figure 4-8] Such a situation may occur during ago-around procedure from a normal landing approach

Set up and trim forfinal approach glide Apply full power to

simulate go-around.Allow nose to rise

As stall approaches,apply forward pressureand establish normal

climb speed.

Trim to maintainnormal climb

Figure 4-8. Elevator trim stall.

Ch 04.qxd 5/7/04 6:47 AM Page 4-11

4-12

or a simulated forced landing approach, orimmediately after a takeoff. The objective of thedemonstration is to show the importance of makingsmooth power applications, overcoming strong trimforces and maintaining positive control of the airplaneto hold safe flight attitudes, and using proper andtimely trim techniques.

At a safe altitude and after ensuring that the area isclear of other air traffic, the pilot should slowly retardthe throttle and extend the landing gear (if retractablegear). One-half to full flaps should be lowered, thethrottle closed, and altitude maintained until theairspeed approaches the normal glide speed. When thenormal glide is established, the airplane should betrimmed for the glide just as would be done during alanding approach (nose-up trim).

During this simulated final approach glide, the throttleis then advanced smoothly to maximum allowablepower as would be done in a go-around procedure. Thecombined forces of thrust, torque, and back-elevatortrim will tend to make the nose rise sharply and turn tothe left.

When the throttle is fully advanced and the pitchattitude increases above the normal climbing attitudeand it is apparent that a stall is approaching, adequateforward pressure must be applied to return the airplaneto the normal climbing attitude. While holding theairplane in this attitude, the trim should then beadjusted to relieve the heavy control pressures and thenormal go-around and level-off procedures completed.

The pilot should recognize when a stall is approaching,and take prompt action to prevent a completely stalledcondition. It is imperative that a stall not occur duringan actual go-around from a landing approach.

Common errors in the performance of intentional stallsare:

• Failure to adequately clear the area.

• Inability to recognize an approaching stallcondition through feel for the airplane.

• Premature recovery.

• Over-reliance on the airspeed indicator whileexcluding other cues.

• Inadequate scanning resulting in an unintentionalwing-low condition during entry.

• Excessive back-elevator pressure resulting in anexaggerated nose-up attitude during entry.

• Inadequate rudder control.

• Inadvertent secondary stall during recovery.

• Failure to maintain a constant bank angle duringturning stalls.

• Excessive forward-elevator pressure duringrecovery resulting in negative load on the wings.

• Excessive airspeed buildup during recovery.

• Failure to take timely action to prevent a full stallduring the conduct of imminent stalls.

SPINSA spin may be defined as an aggravated stall thatresults in what is termed “autorotation” wherein theairplane follows a downward corkscrew path. As theairplane rotates around a vertical axis, the rising wingis less stalled than the descending wing creating arolling, yawing, and pitching motion. The airplane isbasically being forced downward by gravity, rolling,yawing, and pitching in a spiral path. [Figure 4-9]

The autorotation results from an unequal angle ofattack on the airplane’s wings. The rising wing has adecreasing angle of attack, where the relative liftincreases and the drag decreases. In effect, this wing isless stalled. Meanwhile, the descending wing has an

Figure 4-9. Spin—an aggravated stall and autorotation.

Ch 04.qxd 5/7/04 6:47 AM Page 4-12

4-13

increasing angle of attack, past the wing’s critical angleof attack (stall) where the relative lift decreases anddrag increases.

A spin is caused when the airplane’s wing exceeds itscritical angle of attack (stall) with a sideslip or yawacting on the airplane at, or beyond, the actual stall.During this uncoordinated maneuver, a pilot may notbe aware that a critical angle of attack has beenexceeded until the airplane yaws out of control towardthe lowering wing. If stall recovery is not initiatedimmediately, the airplane may enter a spin.

If this stall occurs while the airplane is in a slipping orskidding turn, this can result in a spin entry androtation in the direction that the rudder is beingapplied, regardless of which wingtip is raised.

Many airplanes have to be forced to spin and requireconsiderable judgment and technique to get the spinstarted. These same airplanes that have to be forced tospin, may be accidentally put into a spin bymishandling the controls in turns, stalls, and flight atminimum controllable airspeeds. This fact is additionalevidence of the necessity for the practice of stalls untilthe ability to recognize and recover from themis developed.

Often a wing will drop at the beginning of a stall.When this happens, the nose will attempt to move(yaw) in the direction of the low wing. This is whereuse of the rudder is important during a stall. Thecorrect amount of opposite rudder must be applied tokeep the nose from yawing toward the low wing. Bymaintaining directional control and not allowing thenose to yaw toward the low wing, before stall recoveryis initiated, a spin will be averted. If the nose is allowedto yaw during the stall, the airplane will begin to slip inthe direction of the lowered wing, and will enter a spin.An airplane must be stalled in order to enter a spin;therefore, continued practice in stalls will help the pilotdevelop a more instinctive and prompt reaction inrecognizing an approaching spin. It is essential to learnto apply immediate corrective action any time it isapparent that the airplane is nearing spin conditions. Ifit is impossible to avoid a spin, the pilot shouldimmediately execute spin recovery procedures.

SPIN PROCEDURESThe flight instructor should demonstrate spins in thoseairplanes that are approved for spins. Special spinprocedures or techniques required for a particularairplane are not presented here. Before beginning anyspin operations, the following items should bereviewed.

• The airplane’s AFM/POH limitations section,placards, or type certification data, to determine ifthe airplane is approved for spins.

• Weight and balance limitations.

• Recommended entry and recovery procedures.

• The requirements for parachutes. It would beappropriate to review a current Title 14 of theCode of Federal Regulations (14 CFR) part 91 forthe latest parachute requirements.

A thorough airplane preflight should be accomplishedwith special emphasis on excess or loose items thatmay affect the weight, center of gravity, and controlla-bility of the airplane. Slack or loose control cables(particularly rudder and elevator) could prevent fullanti-spin control deflections and delay or precluderecovery in some airplanes.

Prior to beginning spin training, the flight area, aboveand below the airplane, must be clear of other airtraffic. This may be accomplished while slowing theairplane for the spin entry. All spin training should beinitiated at an altitude high enough for a completedrecovery at or above 1,500 feet AGL.

It may be appropriate to introduce spin training by firstpracticing both power-on and power-off stalls, in aclean configuration. This practice would be used tofamiliarize the student with the airplane’s specific stalland recovery characteristics. Care should be taken withthe handling of the power (throttle) in entries andduring spins. Carburetor heat should be appliedaccording to the manufacturer’s recommendations.

There are four phases of a spin: entry, incipient,developed, and recovery. [Figure 4-10 on next page]

ENTRY PHASEThe entry phase is where the pilot provides thenecessary elements for the spin, either accidentally orintentionally. The entry procedure for demonstrating aspin is similar to a power-off stall. During the entry,the power should be reduced slowly to idle, whilesimultaneously raising the nose to a pitch attitude thatwill ensure a stall. As the airplane approaches a stall,smoothly apply full rudder in the direction of thedesired spin rotation while applying full back (up)elevator to the limit of travel. Always maintain theailerons in the neutral position during the spinprocedure unless AFM/POH specifies otherwise.

INCIPIENT PHASEThe incipient phase is from the time the airplane stallsand rotation starts until the spin has fully developed.This change may take up to two turns for most airplanes.Incipient spins that are not allowed to develop into asteady-state spin are the most commonly used in theintroduction to spin training and recovery techniques. In

Ch 04.qxd 5/7/04 6:47 AM Page 4-13

4-14

this phase, the aerodynamic and inertial forces have notachieved a balance. As the incipient spin develops, theindicated airspeed should be near or below stall air-speed, and the turn-and-slip indicator should indicatethe direction of the spin.

The incipient spin recovery procedure should becommenced prior to the completion of 360° ofrotation. The pilot should apply full rudder oppositethe direction of rotation. If the pilot is not sure of thedirection of the spin, check the turn-and-slip indicator;it will show a deflection in the direction of rotation.

DEVELOPED PHASEThe developed phase occurs when the airplane’sangular rotation rate, airspeed, and vertical speed are

stabilized while in a flightpath that is nearly vertical.This is where airplane aerodynamic forces and inertialforces are in balance, and the attitude, angles, and self-sustaining motions about the vertical axis are constantor repetitive. The spin is in equilibrium.

RECOVERY PHASEThe recovery phase occurs when the angle of attack ofthe wings decreases below the critical angle of attackand autorotation slows. Then the nose steepens androtation stops. This phase may last for a quarter turn toseveral turns.

To recover, control inputs are initiated to disrupt thespin equilibrium by stopping the rotation and stall. Toaccomplish spin recovery, the manufacturer’s

Less Stalled

Stall

More Drag

Relative WindGreaterAngle ofAttack

Chord Line

Relative Wind

LessAngle ofAttack

Chord Line

INCIPIENT SPIN

• Lasts about 4 to 6 seconds in light aircraft.

• Approximately 2 turns.

FULLY DEVELOPED SPIN

• Airspeed, vertical speed, and rate of rotation are stabilized.

• Small, training aircraft lose approximately 500 feet per each 3 second turn.

RECOVERY

• Wings regain lift.• Training aircraft

usually recover in about 1/4 to 1/2 of a turn after anti-spin inputs are applied.

More Stalled

Figure 4-10. Spin entry and recovery.

Ch 04.qxd 5/7/04 6:47 AM Page 4-14

4-15

recommended procedures should be followed. In theabsence of the manufacturer’s recommended spinrecovery procedures and techniques, the followingspin recovery procedures are recommended.

Step 1—REDUCE THE POWER (THROTTLE)TO IDLE. Power aggravates the spincharacteristics. It usually results in a flatter spinattitude and increased rotation rates.

Step 2—POSITION THE AILERONS TONEUTRAL. Ailerons may have an adverse effecton spin recovery. Aileron control in the directionof the spin may speed up the rate of rotation anddelay the recovery. Aileron control opposite thedirection of the spin may cause the down aileronto move the wing deeper into the stall andaggravate the situation. The best procedure is toensure that the ailerons are neutral.

Step 3—APPLY FULL OPPOSITE RUDDERAGAINST THE ROTATION. Make sure that full(against the stop) opposite rudder has beenapplied.

Step 4—APPLY A POSITIVE AND BRISK,STRAIGHT FORWARD MOVEMENT OF THEELEVATOR CONTROL FORWARD OF THENEUTRAL TO BREAK THE STALL. Thisshould be done immediately after full rudderapplication. The forceful movement of theelevator will decrease the excessive angle of attackand break the stall. The controls should be heldfirmly in this position. When the stall is “broken,”the spinning will stop.

Step 5—AFTER SPIN ROTATION STOPS,NEUTRALIZE THE RUDDER. If the rudder isnot neutralized at this time, the ensuing increasedairspeed acting upon a deflected rudder will causea yawing or skidding effect.

Slow and overly cautious control movementsduring spin recovery must be avoided. In certaincases it has been found that such movements resultin the airplane continuing to spin indefinitely, evenwith anti-spin inputs. A brisk and positivetechnique, on the other hand, results in a morepositive spin recovery.

Step 6—BEGIN APPLYING BACK-ELEVATORPRESSURE TO RAISE THE NOSE TO LEVELFLIGHT. Caution must be used not to applyexcessive back-elevator pressure after the rotationstops. Excessive back-elevator pressure can causea secondary stall and result in another spin. Careshould be taken not to exceed the “G” load limitsand airspeed limitations during recovery. If the

flaps and/or retractable landing gear are extendedprior to the spin, they should be retracted as soonas possible after spin entry.

It is important to remember that the above spinrecovery procedures and techniques are recommendedfor use only in the absence of the manufacturer’sprocedures. Before any pilot attempts to begin spintraining, that pilot must be familiar with the proceduresprovided by the manufacturer for spin recovery.

The most common problems in spin recovery includepilot confusion as to the direction of spin rotation andwhether the maneuver is a spin versus spiral. If theairspeed is increasing, the airplane is no longer in aspin but in a spiral. In a spin, the airplane is stalled.The indicated airspeed, therefore, should reflectstall speed.

INTENTIONAL SPINSThe intentional spinning of an airplane, for which thespin maneuver is not specifically approved, is NOTauthorized by this handbook or by the Code of FederalRegulations. The official sources for determining if thespin maneuver IS APPROVED or NOT APPROVEDfor a specific airplane are:

• Type Certificate Data Sheets or the AircraftSpecifications.

• The limitation section of the FAA-approvedAFM/POH. The limitation sections may provideadditional specific requirements for spinauthorization, such as limiting gross weight, CGrange, and amount of fuel.

• On a placard located in clear view of the pilot inthe airplane, NO ACROBATIC MANEUVERSINCLUDING SPINS APPROVED. In airplanesplacarded against spins, there is no assurance thatrecovery from a fully developed spin is possible.

There are occurrences involving airplanes whereinspin restrictions are intentionally ignored by somepilots. Despite the installation of placards prohibitingintentional spins in these airplanes, a number of pilots,and some flight instructors, attempt to justify themaneuver, rationalizing that the spin restriction resultsmerely because of a “technicality” in the airworthinessstandards.

Some pilots reason that the airplane was spin testedduring its certification process and, therefore, noproblem should result from demonstrating orpracticing spins. However, those pilots overlook thefact that a normal category airplane certification onlyrequires the airplane recover from a one-turn spin innot more than one additional turn or 3 seconds,

Ch 04.qxd 5/7/04 6:47 AM Page 4-15

4-16

whichever takes longer. This same test of controllabil-ity can also be used in certificating an airplane in theUtility category (14 CFR section 23.221 (b)).

The point is that 360° of rotation (one-turn spin) doesnot provide a stabilized spin. If the airplane’scontrollability has not been explored by theengineering test pilot beyond the certificationrequirements, prolonged spins (inadvertent orintentional) in that airplane place an operating pilot inan unexplored flight situation. Recovery may bedifficult or impossible.

In 14 CFR part 23, “Airworthiness Standards: Normal,Utility, Acrobatic, and Commuter CategoryAirplanes,” there are no requirements for investigationof controllability in a true spinning condition for theNormal category airplanes. The one-turn “margin ofsafety” is essentially a check of the airplane’s control-lability in a delayed recovery from a stall. Therefore,in airplanes placarded against spins there is absolutelyno assurance whatever that recovery from a fullydeveloped spin is possible under any circumstances.The pilot of an airplane placarded against intentionalspins should assume that the airplane may well becomeuncontrollable in a spin.

WEIGHT AND BALANCE REQUIREMENTSWith each airplane that is approved for spinning, theweight and balance requirements are important forsafe performance and recovery from the spin maneu-ver. Pilots must be aware that just minor weight orbalance changes can affect the airplane’s spinrecovery characteristics. Such changes can eitheralter or enhance the spin maneuver and/or recoverycharacteristics. For example, the addition of weightin the aft baggage compartment, or additional fuel,may still permit the airplane to be operated withinCG, but could seriously affect the spin and recoverycharacteristics.

An airplane that may be difficult to spin intentionallyin the Utility Category (restricted aft CG and reducedweight) could have less resistance to spin entry in theNormal Category (less restricted aft CG and increasedweight). This situation is due to the airplane being ableto generate a higher angle of attack and load factor.Furthermore, an airplane that is approved for spins inthe Utility Category, but loaded in the NormalCategory, may not recover from a spin that is allowedto progress beyond the incipient phase.

Common errors in the performance of intentionalspins are:

• Failure to apply full rudder pressure in the desiredspin direction during spin entry.

• Failure to apply and maintain full up-elevatorpressure during spin entry, resulting in a spiral.

• Failure to achieve a fully stalled condition prior tospin entry.

• Failure to apply full rudder against the spin duringrecovery.

• Failure to apply sufficient forward-elevatorpressure during recovery.

• Failure to neutralize the rudder during recoveryafter rotation stops, resulting in a possiblesecondary spin.

• Slow and overly cautious control movementsduring recovery.

• Excessive back-elevator pressure after rotationstops, resulting in possible secondary stall.

• Insufficient back-elevator pressure duringrecovery resulting in excessive airspeed.

Ch 04.qxd 5/7/04 6:47 AM Page 4-16

GENERALThis chapter discusses takeoffs and departure climbs intricycle landing gear (nosewheel-type) airplanes undernormal conditions, and under conditions which requiremaximum performance. A thorough knowledge oftakeoff principles, both in theory and practice, willoften prove of extreme value throughout a pilot’scareer. It will often prevent an attempted takeoff thatwould result in an accident, or during an emergency,make possible a takeoff under critical conditions whena pilot with a less well rounded knowledge and tech-nique would fail.

The takeoff, though relatively simple, often presentsthe most hazards of any part of a flight. The importanceof thorough knowledge and faultless technique andjudgment cannot be overemphasized.

It must be remembered that the manufacturer’s recom-mended procedures, including airplane configuration andairspeeds, and other information relevant to takeoffs anddeparture climbs in a specific make and model airplane arecontained in the FAA-approved Airplane Flight Manualand/or Pilot’s Operating Handbook (AFM/POH) for thatairplane. If any of the information in this chapter differs

from the airplane manufacturer’s recommendations ascontained in the AFM/POH, the airplane manufacturer’srecommendations take precedence.

TERMS AND DEFINITIONSAlthough the takeoff and climb is one continuousmaneuver, it will be divided into three separate stepsfor purposes of explanation: (1) the takeoff roll, (2) thelift-off, and (3) the initial climb after becoming air-borne. [Figure 5-1]

• Takeoff Roll (ground roll)—the portion of thetakeoff procedure during which the airplane isaccelerated from a standstill to an airspeed thatprovides sufficient lift for it to become airborne.

• Lift-off (rotation)—the act of becoming air-borne as a result of the wings lifting the airplaneoff the ground or the pilot rotating the nose up,increasing the angle of attack to start a climb.

• Initial Climb—begins when the airplane leavesthe ground and a pitch attitude has been estab-lished to climb away from the takeoff area.Normally, it is considered complete when theairplane has reached a safe maneuvering altitude,or an en route climb has been established.

5-1Figure 5-1.Takeoff and climb.

Takeoffpower

Takeoff pitchattitude

Best climb speed

Safe maneuvering altitudeclimb power

En Routeclimb

Climb(3)

Lift-off(2)

Takeoffroll(1)

Ch 05.qxd 5/7/04 7:02 AM Page 5-1

5-2

PRIOR TO TAKEOFFBefore taxiing onto the runway or takeoff area, thepilot should ensure that the engine is operating prop-erly and that all controls, including flaps and trim tabs,are set in accordance with the before takeoff checklist.In addition, the pilot must make certain that theapproach and takeoff paths are clear of other aircraft.At uncontrolled airports, pilots should announce theirintentions on the common traffic advisory frequency(CTAF) assigned to that airport. When operating froman airport with an operating control tower, pilots mustcontact the tower operator and receive a takeoff clear-ance before taxiing onto the active runway.

It is not recommended to take off immediately behindanother aircraft, particularly large, heavily loadedtransport airplanes, because of the wake turbulencethat is generated.

While taxiing onto the runway, the pilot can selectground reference points that are aligned with therunway direction as aids to maintaining directionalcontrol during the takeoff. These may be runwaycenterline markings, runway lighting, distant trees,towers, buildings, or mountain peaks.

NORMAL TAKEOFFA normal takeoff is one in which the airplane is headedinto the wind, or the wind is very light. Also, the take-off surface is firm and of sufficient length to permit theairplane to gradually accelerate to normal lift-off andclimb-out speed, and there are no obstructions alongthe takeoff path.

There are two reasons for making a takeoff as nearlyinto the wind as possible. First, the airplane’s speedwhile on the ground is much less than if the takeoffwere made downwind, thus reducing wear and stresson the landing gear. Second, a shorter ground roll andtherefore much less runway length is required todevelop the minimum lift necessary for takeoff andclimb. Since the airplane depends on airspeed in orderto fly, a headwind provides some of that airspeed, evenwith the airplane motionless, from the wind flowingover the wings.

TAKEOFF ROLLAfter taxiing onto the runway, the airplane should becarefully aligned with the intended takeoff direction,and the nosewheel positioned straight, or centered.After releasing the brakes, the throttle should beadvanced smoothly and continuously to takeoff power.An abrupt application of power may cause the airplaneto yaw sharply to the left because of the torque effectsof the engine and propeller. This will be most apparentin high horsepower engines. As the airplane starts toroll forward, the pilot should assure both feet are on

the rudder pedals so that the toes or balls of the feet areon the rudder portions, not on the brake portions.Engine instruments should be monitored during thetakeoff roll for any malfunctions.

In nosewheel-type airplanes, pressures on the elevatorcontrol are not necessary beyond those needed tosteady it. Applying unnecessary pressure will onlyaggravate the takeoff and prevent the pilot from recog-nizing when elevator control pressure is actuallyneeded to establish the takeoff attitude.

As speed is gained, the elevator control will tend toassume a neutral position if the airplane is correctlytrimmed. At the same time, directional control shouldbe maintained with smooth, prompt, positive ruddercorrections throughout the takeoff roll. The effects ofengine torque and P-factor at the initial speeds tend topull the nose to the left. The pilot must use whateverrudder pressure and aileron needed to correct for theseeffects or for existing wind conditions to keep the noseof the airplane headed straight down the runway. Theuse of brakes for steering purposes should be avoided,since this will cause slower acceleration of the air-plane’s speed, lengthen the takeoff distance, andpossibly result in severe swerving.

While the speed of the takeoff roll increases, moreand more pressure will be felt on the flight controls,particularly the elevators and rudder. If the tail sur-faces are affected by the propeller slipstream, theybecome effective first. As the speed continues toincrease, all of the flight controls will graduallybecome effective enough to maneuver the airplaneabout its three axes. It is at this point, in the taxi toflight transition, that the airplane is being flown morethan taxied. As this occurs, progressively smallerrudder deflections are needed to maintain direction.

The feel of resistance to the movement of the con-trols and the airplane’s reaction to such movementsare the only real indicators of the degree of controlattained. This feel of resistance is not a measure ofthe airplane’s speed, but rather of its controllability.To determine the degree of controllability, the pilotmust be conscious of the reaction of the airplane tothe control pressures and immediately adjust thepressures as needed to control the airplane. The pilotmust wait for the reaction of the airplane to theapplied control pressures and attempt to sense thecontrol resistance to pressure rather than attempt tocontrol the airplane by movement of the controls.Balanced control surfaces increase the importanceof this point, because they materially reduce theintensity of the resistance offered to pressuresexerted by the pilot.

Ch 05.qxd 5/7/04 7:02 AM Page 5-2

5-3

At this stage of training, beginning takeoff practice, astudent pilot will normally not have a full appreciationof the variations of control pressures with the speed ofthe airplane. The student, therefore, may tend to movethe controls through wide ranges seeking the pressuresthat are familiar and expected, and as a consequenceover-control the airplane. The situation may be aggra-vated by the sluggish reaction of the airplane to thesemovements. The flight instructor should take measuresto check these tendencies and stress the importance ofthe development of feel. The student pilot should berequired to feel lightly for resistance and accomplishthe desired results by applying pressure against it. Thispractice will enable the student pilot, as experience isgained, to achieve a sense of the point when sufficientspeed has been acquired for the takeoff, instead ofmerely guessing, fixating on the airspeed indicator, ortrying to force performance from the airplane.

LIFT-OFFSince a good takeoff depends on the proper takeoffattitude, it is important to know how this attitudeappears and how it is attained. The ideal takeoff atti-tude requires only minimum pitch adjustmentsshortly after the airplane lifts off to attain the speedfor the best rate of climb (VY). [Figure 5-2] The pitchattitude necessary for the airplane to accelerate to VYspeed should be demonstrated by the instructor andmemorized by the student. Initially, the student pilotmay have a tendency to hold excessive back-elevatorpressure just after lift-off, resulting in an abrupt pitch-up. The flight instructor should be prepared for this.

Each type of airplane has a best pitch attitude fornormal lift-off; however, varying conditions maymake a difference in the required takeoff technique.A rough field, a smooth field, a hard surface runway,or a short or soft, muddy field, all call for a slightly

different technique, as will smooth air in contrast toa strong, gusty wind. The different techniques forthose other-than-normal conditions are discussedlater in this chapter.

When all the flight controls become effective duringthe takeoff roll in a nosewheel-type airplane, back-elevator pressure should be gradually applied toraise the nosewheel slightly off the runway, thusestablishing the takeoff or lift-off attitude. This isoften referred to as “rotating.” At this point, theposition of the nose in relation to the horizon shouldbe noted, then back-elevator pressure applied asnecessary to hold this attitude. The wings must bekept level by applying aileron pressure as necessary.

The airplane is allowed to fly off the ground while inthe normal takeoff attitude. Forcing it into the air byapplying excessive back-elevator pressure would onlyresult in an excessively high pitch attitude and maydelay the takeoff. As discussed earlier, excessive andrapid changes in pitch attitude result in proportionatechanges in the effects of torque, thus making the air-plane more difficult to control.

Although the airplane can be forced into the air, this isconsidered an unsafe practice and should be avoidedunder normal circumstances. If the airplane is forcedto leave the ground by using too much back-elevatorpressure before adequate flying speed is attained, thewing’s angle of attack may be excessive, causing theairplane to settle back to the runway or even to stall.On the other hand, if sufficient back-elevator pressureis not held to maintain the correct takeoff attitude afterbecoming airborne, or the nose is allowed to lowerexcessively, the airplane may also settle back to therunway. This would occur because the angle of attackis decreased and lift diminished to the degree where itwill not support the airplane. It is important, then, tohold the correct attitude constant after rotation or lift-off.

As the airplane leaves the ground, the pilot mustcontinue to be concerned with maintaining thewings in a level attitude, as well as holding theproper pitch attitude. Outside visual scan toattain/maintain proper airplane pitch and bank atti-tude must be intensified at this critical point. Theflight controls have not yet become fully effective,and the beginning pilot will often have a tendencyto fixate on the airplane’s pitch attitude and/or theairspeed indicator and neglect the natural tendencyof the airplane to roll just after breaking ground.

During takeoffs in a strong, gusty wind, it is advisablethat an extra margin of speed be obtained before theairplane is allowed to leave the ground. A takeoff at thenormal takeoff speed may result in a lack of positiveFigure 5-2. Initial roll and takeoff attitude.

A. Initial roll

B. Takeoff attitude

Ch 05.qxd 5/7/04 7:02 AM Page 5-3

5-4

control, or a stall, when the airplane encounters asudden lull in strong, gusty wind, or other turbulentair currents. In this case, the pilot should allow theairplane to stay on the ground longer to attain morespeed; then make a smooth, positive rotation to leavethe ground.

INITIAL CLIMBUpon lift-off, the airplane should be flying at approxi-mately the pitch attitude that will allow it to accelerateto VY. This is the speed at which the airplane will gainthe most altitude in the shortest period of time.

If the airplane has been properly trimmed, some back-elevator pressure may be required to hold this attitudeuntil the proper climb speed is established. On theother hand, relaxation of any back-elevator pressurebefore this time may result in the airplane settling,even to the extent that it contacts the runway.

The airplane will pick up speed rapidly after itbecomes airborne. Once a positive rate of climb isestablished, the flaps and landing gear can be retracted(if equipped).

It is recommended that takeoff power be maintaineduntil reaching an altitude of at least 500 feet above thesurrounding terrain or obstacles. The combination ofVY and takeoff power assures the maximum altitudegained in a minimum amount of time. This gives thepilot more altitude from which the airplane can besafely maneuvered in case of an engine failure or otheremergency.

Since the power on the initial climb is fixed at the takeoffpower setting, the airspeed must be controlled by makingslight pitch adjustments using the elevators. However,the pilot should not fixate on the airspeed indicator whenmaking these pitch changes, but should, instead, continueto scan outside to adjust the airplane’s attitude in relationto the horizon. In accordance with the principles of atti-tude flying, the pilot should first make the necessarypitch change with reference to the natural horizon andhold the new attitude momentarily, and then glance at theairspeed indicator as a check to see if the new attitude iscorrect. Due to inertia, the airplane will not accelerate ordecelerate immediately as the pitch is changed. It takes alittle time for the airspeed to change. If the pitch attitudehas been over or under corrected, the airspeed indicatorwill show a speed that is more or less than that desired.When this occurs, the cross-checking and appropriatepitch-changing process must be repeated until the desiredclimbing attitude is established.

When the correct pitch attitude has been attained, itshould be held constant while cross-checking it againstthe horizon and other outside visual references. The

airspeed indicator should be used only as a check todetermine if the attitude is correct.

After the recommended climb airspeed has been estab-lished, and a safe maneuvering altitude has beenreached, the power should be adjusted to the recom-mended climb setting and the airplane trimmed torelieve the control pressures. This will make it easierto hold a constant attitude and airspeed.

During initial climb, it is important that the takeoffpath remain aligned with the runway to avoid driftinginto obstructions, or the path of another aircraft thatmay be taking off from a parallel runway. Proper scan-ning techniques are essential to a safe takeoff andclimb, not only for maintaining attitude and direction,but also for collision avoidance in the airport area.

When the student pilot nears the solo stage of flighttraining, it should be explained that the airplane’stakeoff performance will be much different when theinstructor is out of the airplane. Due to decreasedload, the airplane will become airborne sooner andwill climb more rapidly. The pitch attitude that thestudent has learned to associate with initial climbmay also differ due to decreased weight, and theflight controls may seem more sensitive. If the situa-tion is unexpected, it may result in increased tensionthat may remain until after the landing. Frequently,the existence of this tension and the uncertainty thatdevelops due to the perception of an “abnormal”takeoff results in poor performance on the subse-quent landing.

Common errors in the performance of normal takeoffsand departure climbs are:

• Failure to adequately clear the area prior to taxi-ing into position on the active runway.

• Abrupt use of the throttle.

• Failure to check engine instruments for signs ofmalfunction after applying takeoff power.

• Failure to anticipate the airplane’s left turningtendency on initial acceleration.

• Overcorrecting for left turning tendency.

• Relying solely on the airspeed indicator ratherthan developed feel for indications of speed andairplane controllability during acceleration andlift-off.

• Failure to attain proper lift-off attitude.

• Inadequate compensation for torque/P-factorduring initial climb resulting in a sideslip.

• Over-control of elevators during initial climb-out.

Ch 05.qxd 5/7/04 7:02 AM Page 5-4

5-5

• Limiting scan to areas directly ahead of the air-plane (pitch attitude and direction), resulting inallowing a wing (usually the left) to dropimmediately after lift-off.

• Failure to attain/maintain best rate-of-climb air-speed (VY).

• Failure to employ the principles of attitude flyingduring climb-out, resulting in “chasing” the air-speed indicator.

CROSSWIND TAKEOFFWhile it is usually preferable to take off directly intothe wind whenever possible or practical, there willbe many instances when circumstances or judgmentwill indicate otherwise. Therefore, the pilot must befamiliar with the principles and techniques involvedin crosswind takeoffs, as well as those for normaltakeoffs. A crosswind will affect the airplane duringtakeoff much as it does in taxiing. With this in mind,it can be seen that the technique for crosswindcorrection during takeoffs closely parallels thecrosswind correction techniques used in taxiing.

TAKEOFF ROLLThe technique used during the initial takeoff roll in acrosswind is generally the same as used in a normal

takeoff, except that aileron control must be held INTOthe crosswind. This raises the aileron on the upwindwing to impose a downward force on the wing to coun-teract the lifting force of the crosswind and preventsthe wing from rising.

As the airplane is taxied into takeoff position, it is essen-tial that the windsock and other wind direction indicatorsbe checked so that the presence of a crosswind may berecognized and anticipated. If a crosswind is indicated,FULL aileron should be held into the wind as the takeoffroll is started. This control position should be maintainedwhile the airplane is accelerating and until the aileronsstart becoming sufficiently effective for maneuvering theairplane about its longitudinal axis.

With the aileron held into the wind, the takeoff pathmust be held straight with the rudder. [Figure 5-3]

Normally, this will require applying downwind rudderpressure, since on the ground the airplane will tend toweathervane into the wind. When takeoff power isapplied, torque or P-factor that yaws the airplane to theleft may be sufficient to counteract the weathervaningtendency caused by a crosswind from the right. On theother hand, it may also aggravate the tendency to

Figure 5-3. Crosswind takeoff roll and initial climb.

WIND

Apply full aileron into windRudder as needed for direction

Hold aileron into windRoll on upwind wheel

Rudder as needed

Hold aileron into windBank into wind

Rudder as needed

Start roll

Takeoff roll

Lift-off

Initial climb

Wings level with a wind correction

angle

Ch 05.qxd 5/7/04 7:02 AM Page 5-5

5-6

swerve left when the wind is from the left. In any case,whatever rudder pressure is required to keep the air-plane rolling straight down the runway should beapplied.

As the forward speed of the airplane increases and thecrosswind becomes more of a relative headwind, themechanical holding of full aileron into the wind shouldbe reduced. It is when increasing pressure is being felton the aileron control that the ailerons are becomingmore effective. As the aileron’s effectiveness increasesand the crosswind component of the relative windbecomes less effective, it will be necessary to graduallyreduce the aileron pressure. The crosswind componenteffect does not completely vanish, so some aileron pres-sure will have to be maintained throughout the takeoffroll to keep the crosswind from raising the upwind wing.If the upwind wing rises, thus exposing more surface tothe crosswind, a “skipping” action may result. [Figure5-4]

This is usually indicated by a series of very smallbounces, caused by the airplane attempting to flyand then settling back onto the runway. During thesebounces, the crosswind also tends to move the air-plane sideways, and these bounces will develop intoside-skipping. This side-skipping imposes severeside stresses on the landing gear and could result instructural failure.

It is important, during a crosswind takeoff roll, to holdsufficient aileron into the wind not only to keep theupwind wing from rising but to hold that wing down sothat the airplane will, immediately after lift-off, besideslipping into the wind enough to counteract drift.

LIFT-OFFAs the nosewheel is being raised off the runway, theholding of aileron control into the wind may result in

the downwind wing rising and the downwind mainwheel lifting off the runway first, with the remainderof the takeoff roll being made on that one main wheel.This is acceptable and is preferable to side-skipping.

If a significant crosswind exists, the main wheelsshould be held on the ground slightly longer than in anormal takeoff so that a smooth but very definite lift-off can be made. This procedure will allow the air-plane to leave the ground under more positive controlso that it will definitely remain airborne while theproper amount of wind correction is being established.More importantly, this procedure will avoid imposingexcessive side-loads on the landing gear and preventpossible damage that would result from the airplanesettling back to the runway while drifting.

As both main wheels leave the runway and groundfriction no longer resists drifting, the airplane will beslowly carried sideways with the wind unless adequatedrift correction is maintained by the pilot. Therefore, itis important to establish and maintain the properamount of crosswind correction prior to lift-off byapplying aileron pressure toward the wind to keep theupwind wing from rising and applying rudder pressureas needed to prevent weathervaning.

INITIAL CLIMBIf proper crosswind correction is being applied, as soonas the airplane is airborne, it will be sideslipping into thewind sufficiently to counteract the drifting effect of thewind. [Figure 5-5] This sideslipping should be continueduntil the airplane has a positive rate of climb. At that time,the airplane should be turned into the wind to establishjust enough wind correction angle to counteract the windand then the wings rolled level. Firm and aggressive useof the rudders will be required to keep the airplane headedstraight down the runway. The climb with a wind correc-tion angle should be continued to follow a ground trackaligned with the runway direction. However, because theforce of a crosswind may vary markedly within a fewhundred feet of the ground, frequent checks of actualground track should be made, and the wind correctionadjusted as necessary. The remainder of the climb tech-nique is the same used for normal takeoffs and climbs.

Common errors in the performance of crosswind take-offs are:

• Failure to adequately clear the area prior to taxi-ing onto the active runway.

• Using less than full aileron pressure into thewind initially on the takeoff roll.

• Mechanical use of aileron control rather thansensing the need for varying aileron controlinput through feel for the airplane.

No correction

WIND

WIND

Proper correction

Figure 5-4. Crosswind effect.

Ch 05.qxd 5/7/04 7:02 AM Page 5-6

5-7

• Premature lift-off resulting in side-skipping.

• Excessive aileron input in the latter stage of thetakeoff roll resulting in a steep bank into the windat lift-off.

• Inadequate drift correction after lift-off.

GROUND EFFECT ON TAKEOFFGround effect is a condition of improved perform-ance encountered when the airplane is operatingvery close to the ground. Ground effect can bedetected and measured up to an altitude equal to onewingspan above the surface. [Figure 5-6] However,ground effect is most significant when the airplane(especially a low-wing airplane) is maintaining aconstant attitude at low airspeed at low altitude (forexample, during takeoff when the airplane lifts offand accelerates to climb speed, and during the land-ing flare before touchdown).

When the wing is under the influence of ground effect,there is a reduction in upwash, downwash, and wingtipvortices. As a result of the reduced wingtip vortices,induced drag is reduced. When the wing is at a heightequal to one-fourth the span, the reduction in induceddrag is about 25 percent, and when the wing is at aheight equal to one-tenth the span, the reduction ininduced drag is about 50 percent. At high speeds whereparasite drag dominates, induced drag is a small part ofthe total drag. Consequently, the effects of ground effectare of greater concern during takeoff and landing.

On takeoff, the takeoff roll, lift-off, and the beginningof the initial climb are accomplished in the groundeffect area. The ground effect causes local increases instatic pressure, which cause the airspeed indicator andaltimeter to indicate slightly less than they should, andusually results in the vertical speed indicator indicat-ing a descent. As the airplane lifts off and climbs out ofthe ground effect area, however, the following willoccur.

• The airplane will require an increase in angle ofattack to maintain the same lift coefficient.

• The airplane will experience an increase ininduced drag and thrust required.

• The airplane will experience a pitch-up tendencyand will require less elevator travel because of anincrease in downwash at the horizontal tail.

WIND

Figure 5-5. Crosswind climb flightpath.

Ground effectdecreasesinduced drag

Airplane mayfly at lower indicated airspeed

Accelerate inground effectto V or VX Y

Ground effectdecreases quicklywith height

Ground effect isnegligible whenheight is equalto wingspan

GroundEffectArea

Figure 5-6.Takeoff in ground effect area.

Ch 05.qxd 5/7/04 7:02 AM Page 5-7

5-8

• The airplane will experience a reduction in staticsource pressure as it leaves the ground effect areaand a corresponding increase in indicated air-speed.

Due to the reduced drag in ground effect, the airplanemay seem to be able to take off below the recom-mended airspeed. However, as the airplane rises out ofground effect with an insufficient airspeed, initialclimb performance may prove to be marginal becauseof the increased drag. Under conditions of high-den-sity altitude, high temperature, and/or maximum grossweight, the airplane may be able to become airborne atan insufficient airspeed, but unable to climb out ofground effect. Consequently, the airplane may not beable to clear obstructions, or may settle back on therunway. The point to remember is that additionalpower is required to compensate for increases in dragthat occur as an airplane leaves ground effect. But dur-ing an initial climb, the engine is already developingmaximum power. The only alternative is to lower pitchattitude to gain additional airspeed, which will result ininevitable altitude loss. Therefore, under marginal con-ditions, it is important that the airplane takes off at therecommended speed that will provide adequate initialclimb performance.

Ground effect is important to normal flight operations.If the runway is long enough, or if no obstacles exist,ground effect can be used to an advantage by using thereduced drag to improve initial acceleration.Additionally, the procedure for takeoff from unsatis-factory surfaces is to take as much weight on the wingsas possible during the ground run, and to lift off withthe aid of ground effect before true flying speed isattained. It is then necessary to reduce the angle ofattack to attain normal airspeed before attempting tofly away from the ground effect area.

SHORT-FIELD TAKEOFF AND MAXIMUM PERFORMANCE CLIMBTakeoffs and climbs from fields where the takeoff areais short or the available takeoff area is restricted byobstructions require that the pilot operate the airplaneat the limit of its takeoff performance capabilities. Todepart from such an area safely, the pilot must exercisepositive and precise control of airplane attitude andairspeed so that takeoff and climb performance resultsin the shortest ground roll and the steepest angle ofclimb. [Figure 5-7]

The achieved result should be consistent with theperformance section of the FAA-approved AirplaneFlight Manual and/or Pilot’s Operating Handbook(AFM/POH). In all cases, the power setting, flapsetting, airspeed, and procedures prescribed by theairplane’s manufacturer should be followed.

In order to accomplish a maximum performance take-off safely, the pilot must have adequate knowledge inthe use and effectiveness of the best angle-of-climbspeed (VX) and the best rate-of-climb speed (VY) forthe specific make and model of airplane being flown.

The speed for VX is that which will result in thegreatest gain in altitude for a given distance over theground. It is usually slightly less than VY which pro-vides the greatest gain in altitude per unit of time.The specific speeds to be used for a given airplaneare stated in the FAA-approved AFM/POH. It shouldbe emphasized that in some airplanes, a deviation of5 knots from the recommended speed will result in asignificant reduction in climb performance.Therefore, precise control of airspeed has an impor-tant bearing on the successful execution as well asthe safety of the maneuver.

Climbat VY

Retract gearand flaps

Climbat VX

Rotate atapproximately VX

Figure 5-7. Short-field takeoff.

Ch 05.qxd 5/7/04 7:02 AM Page 5-8

5-9

TAKEOFF ROLLTaking off from a short field requires the takeoff to bestarted from the very beginning of the takeoff area. Atthis point, the airplane is aligned with the intendedtakeoff path. If the airplane manufacturer recommendsthe use of flaps, they should be extended the properamount before starting the takeoff roll. This permitsthe pilot to give full attention to the proper techniqueand the airplane’s performance throughout the takeoff.

Some authorities prefer to hold the brakes until themaximum obtainable engine r.p.m. is achieved beforeallowing the airplane to begin its takeoff run. However,it has not been established that this procedure willresult in a shorter takeoff run in all light single-engineairplanes. Takeoff power should be applied smoothlyand continuously—without hesitation—to acceleratethe airplane as rapidly as possible. The airplane shouldbe allowed to roll with its full weight on the mainwheels and accelerated to the lift-off speed. As thetakeoff roll progresses, the airplane’s pitch attitude andangle of attack should be adjusted to that which resultsin the minimum amount of drag and the quickest accel-eration. In nosewheel-type airplanes, this will involvelittle use of the elevator control, since the airplane isalready in a low drag attitude.

LIFT-OFFApproaching best angle-of-climb speed (VX), the airplaneshould be smoothly and firmly lifted off, or rotated, byapplying back-elevator pressure to an attitude that willresult in the best angle-of-climb airspeed (VX). Since theairplane will accelerate more rapidly after lift-off, addi-tional back-elevator pressure becomes necessary to hold aconstant airspeed. After becoming airborne, a wings levelclimb should be maintained at VX until obstacles havebeen cleared or, if no obstacles are involved, until an alti-tude of at least 50 feet above the takeoff surface is attained.Thereafter, the pitch attitude may be lowered slightly, andthe climb continued at best rate-of-climb speed (VY) untilreaching a safe maneuvering altitude. Remember that anattempt to pull the airplane off the ground prematurely, orto climb too steeply, may cause the airplane to settle backto the runway or into the obstacles. Even if the airplaneremains airborne, the initial climb will remain flat andclimb performance/obstacle clearance ability seriouslydegraded until best angle-of-climb airspeed (VX) isachieved. [Figure 5-8]

The objective is to rotate to the appropriate pitch atti-tude at (or near) best angle-of-climb airspeed. It shouldbe remembered, however, that some airplanes willhave a natural tendency to lift off well before reachingVX. In these airplanes, it may be necessary to allow theairplane to lift off in ground effect and then reducepitch attitude to level until the airplane accelerates tobest angle-of-climb airspeed with the wheels just clearof the runway surface. This method is preferable toforcing the airplane to remain on the ground with for-ward-elevator pressure until best angle-of-climb speedis attained. Holding the airplane on the ground unnec-essarily puts excessive pressure on the nosewheel, mayresult in “wheelbarrowing,” and will hinder bothacceleration and overall airplane performance.

INITIAL CLIMBOn short-field takeoffs, the landing gear and flapsshould remain in takeoff position until clear of obsta-cles (or as recommended by the manufacturer) and VYhas been established. It is generally unwise for the pilotto be looking in the cockpit or reaching for landinggear and flap controls until obstacle clearance isassured. When the airplane is stabilized at VY, the gear(if equipped) and then the flaps should be retracted. Itis usually advisable to raise the flaps in increments toavoid sudden loss of lift and settling of the airplane.Next, reduce the power to the normal climb setting oras recommended by the airplane manufacturer.

Common errors in the performance of short-field take-offs and maximum performance climbs are:

• Failure to adequately clear the area.

• Failure to utilize all available runway/takeoffarea.

• Failure to have the airplane properly trimmedprior to takeoff.

• Premature lift-off resulting in high drag.

• Holding the airplane on the ground unnecessarilywith excessive forward-elevator pressure.

• Inadequate rotation resulting in excessive speedafter lift-off.

• Inability to attain/maintain best angle-of-climbairspeed.

Premature rotation Airplane may lift offat low airspeed

Airplane may settleback to the ground

Flight below Vresults in shallowclimb

X

Figure 5-8. Effect of premature lift-off.

Ch 05.qxd 5/7/04 7:02 AM Page 5-9

5-10

• Fixation on the airspeed indicator during initialclimb.

• Premature retraction of landing gear and/or wingflaps.

SOFT/ROUGH-FIELD TAKEOFF AND CLIMBTakeoffs and climbs from soft fields require the use ofoperational techniques for getting the airplane airborneas quickly as possible to eliminate the drag caused bytall grass, soft sand, mud, and snow, and may or maynot require climbing over an obstacle. The techniquemakes judicious use of ground effect and requires afeel for the airplane and fine control touch. These sametechniques are also useful on a rough field where it isadvisable to get the airplane off the ground as soon aspossible to avoid damaging the landing gear.

Soft surfaces or long, wet grass usually reduces the air-plane’s acceleration during the takeoff roll so muchthat adequate takeoff speed might not be attained ifnormal takeoff techniques were employed.

It should be emphasized that the correct takeoffprocedure for soft fields is quite different fromthat appropriate for short fields with firm, smoothsurfaces. To minimize the hazards associated withtakeoffs from soft or rough fields, support of theairplane’s weight must be transferred as rapidlyas possible from the wheels to the wings as thetakeoff roll proceeds. Establishing and maintain-ing a relatively high angle of attack or nose-highpitch attitude as early as possible does this. Wingflaps may be lowered prior to starting the takeoff(if recommended by the manufacturer) to provideadditional lift and to transfer the airplane’s weightfrom the wheels to the wings as early as possible.

Stopping on a soft surface, such as mud or snow, mightbog the airplane down; therefore, it should be kept incontinuous motion with sufficient power while liningup for the takeoff roll.

TAKEOFF ROLLAs the airplane is aligned with the takeoff path, takeoffpower is applied smoothly and as rapidly as the power-plant will accept it without faltering. As the airplane

accelerates, enough back-elevator pressure should beapplied to establish a positive angle of attack and toreduce the weight supported by the nosewheel.

When the airplane is held at a nose-high attitudethroughout the takeoff run, the wings will, as speedincreases and lift develops, progressively relieve thewheels of more and more of the airplane’s weight,thereby minimizing the drag caused by surface irregular-ities or adhesion. If this attitude is accurately maintained,the airplane will virtually fly itself off the ground,becoming airborne at airspeed slower than a safe climbspeed because of ground effect. [Figure 5-9]

LIFT-OFFAfter becoming airborne, the nose should be loweredvery gently with the wheels clear of the surface toallow the airplane to accelerate to VY, or VX if obsta-cles must be cleared. Extreme care must be exercisedimmediately after the airplane becomes airborne andwhile it accelerates, to avoid settling back onto the sur-face. An attempt to climb prematurely or too steeplymay cause the airplane to settle back to the surface asa result of losing the benefit of ground effect. Anattempt to climb out of ground effect before sufficientclimb airspeed is attained may result in the airplanebeing unable to climb further as the ground effect areais transited, even with full power. Therefore, it isessential that the airplane remain in ground effect untilat least VX is reached. This requires feel for the air-plane, and a very fine control touch, in order to avoidover-controlling the elevator as required control pres-sures change with airplane acceleration.

INITIAL CLIMBAfter a positive rate of climb is established, and the air-plane has accelerated to VY, retract the landing gear andflaps, if equipped. If departing from an airstrip with wetsnow or slush on the takeoff surface, the gear should notbe retracted immediately. This allows for any wet snowor slush to be air-dried. In the event an obstacle must becleared after a soft-field takeoff, the climb-out is per-formed at VX until the obstacle has been cleared. Afterreaching this point, the pitch attitude is adjusted to VYand the gear and flaps are retracted. The power maythen be reduced to the normal climb setting.

Accelerate Raise nosewheel Lift offLevel off inground effect

Acceleratein ground effectto VX or VY

Figure 5-9. Soft-field takeoff.

Ch 05.qxd 5/7/04 7:02 AM Page 5-10

5-11

Common errors in the performance of soft/rough fieldtakeoff and climbs are:

• Failure to adequately clear the area.

• Insufficient back-elevator pressure during initialtakeoff roll resulting in inadequate angle ofattack.

• Failure to cross-check engine instruments forindications of proper operation after applyingpower.

• Poor directional control.

• Climbing too steeply after lift-off.

• Abrupt and/or excessive elevator control whileattempting to level off and accelerate after lift-off.

• Allowing the airplane to “mush” or settle result-ing in an inadvertent touchdown after lift-off.

• Attempting to climb out of ground effect areabefore attaining sufficient climb speed.

• Failure to anticipate an increase in pitch attitudeas the airplane climbs out of ground effect.

REJECTED TAKEOFF/ENGINE FAILUREEmergency or abnormal situations can occur during atakeoff that will require a pilot to reject the takeoffwhile still on the runway. Circumstances such as amalfunctioning powerplant, inadequate acceleration,runway incursion, or air traffic conflict may be rea-sons for a rejected takeoff.

Prior to takeoff, the pilot should have in mind apoint along the runway at which the airplaneshould be airborne. If that point is reached and theairplane is not airborne, immediate action shouldbe taken to discontinue the takeoff. Properlyplanned and executed, chances are excellent theairplane can be stopped on the remaining runwaywithout using extraordinary measures, such asexcessive braking that may result in loss of direc-tional control, airplane damage, and/or personalinjury.

In the event a takeoff is rejected, the power should bereduced to idle and maximum braking applied whilemaintaining directional control. If it is necessary toshut down the engine due to a fire, the mixture controlshould be brought to the idle cutoff position and themagnetos turned off. In all cases, the manufacturer’semergency procedure should be followed.

What characterizes all power loss or engine failureoccurrences after lift-off is urgency. In most instances,the pilot has only a few seconds after an engine failureto decide what course of action to take and to executeit. Unless prepared in advance to make the proper deci-sion, there is an excellent chance the pilot will make apoor decision, or make no decision at all and allowevents to rule.

In the event of an engine failure on initial climb-out,the pilot’s first responsibility is to maintain aircraftcontrol. At a climb pitch attitude without power, theairplane will be at or near a stalling angle of attack.At the same time, the pilot may still be holding rightrudder. It is essential the pilot immediately lower thepitch attitude to prevent a stall and possible spin.The pilot should establish a controlled glide towarda plausible landing area (preferably straight aheadon the remaining runway).

NOISE ABATEMENTAircraft noise problems have become a major concern atmany airports throughout the country. Many local com-munities have pressured airports into developing specificoperational procedures that will help limit aircraft noisewhile operating over nearby areas. For years now, theFAA, airport managers, aircraft operators, pilots, and spe-cial interest groups have been working together to mini-mize aircraft noise for nearby sensitive areas. As a result,noise abatement procedures have been developed formany of these airports that include standardized profilesand procedures to achieve these lower noise goals.

Airports that have noise abatement procedures provideinformation to pilots, operators, air carriers, air trafficfacilities, and other special groups that are applicableto their airport. These procedures are available to theaviation community by various means. Most of thisinformation comes from the Airport/Facility Directory,local and regional publications, printed handouts, oper-ator bulletin boards, safety briefings, and local air traf-fic facilities.

At airports that use noise abatement procedures,reminder signs may be installed at the taxiway holdpositions for applicable runways. These are to remindpilots to use and comply with noise abatement proce-dures on departure. Pilots who are not familiar withthese procedures should ask the tower or air trafficfacility for the recommended procedures. In any case,pilots should be considerate of the surrounding com-munity while operating their airplane to and from suchan airport. This includes operating as quietly, yet safelyas possible.

Ch 05.qxd 5/7/04 7:02 AM Page 5-11

5-12

Ch 05.qxd 5/7/04 7:02 AM Page 5-12

PURPOSE AND SCOPEGround reference maneuvers and their related factorsare used in developing a high degree of pilot skill.Although most of these maneuvers are not performedas such in normal everyday flying, the elements andprinciples involved in each are applicable to perform-ance of the customary pilot operations. They aid thepilot in analyzing the effect of wind and other forcesacting on the airplane and in developing a fine con-trol touch, coordination, and the division of attentionnecessary for accurate and safe maneuvering of theairplane.

All of the early part of the pilot’s training has been con-ducted at relatively high altitudes, and for the purposeof developing technique, knowledge of maneuvers,coordination, feel, and the handling of the airplane ingeneral. This training will have required that most ofthe pilot’s attention be given to the actual handling ofthe airplane, and the results of control pressures on theaction and attitude of the airplane.

If permitted to continue beyond the appropriate trainingstage, however, the student pilot’s concentration ofattention will become a fixed habit, one that will seri-ously detract from the student’s ease and safety as apilot, and will be very difficult to eliminate. Therefore,it is necessary, as soon as the pilot shows proficiency inthe fundamental maneuvers, that the pilot be introducedto maneuvers requiring outside attention on a practicalapplication of these maneuvers and the knowledgegained.

It should be stressed that, during ground referencemaneuvers, it is equally important that basic flyingtechnique previously learned be maintained. Theflight instructor should not allow any relaxation of thestudent’s previous standard of technique simplybecause a new factor is added. This requirementshould be maintained throughout the student’sprogress from maneuver to maneuver. Each newmaneuver should embody some advance and includethe principles of the preceding one in order that conti-nuity be maintained. Each new factor introducedshould be merely a step-up of one already learned sothat orderly, consistent progress can be made.

MANEUVERING BY REFERENCETO GROUND OBJECTSGround track or ground reference maneuvers are per-formed at a relatively low altitude while applying winddrift correction as needed to follow a predeterminedtrack or path over the ground. They are designed todevelop the ability to control the airplane, and to recog-nize and correct for the effect of wind while dividingattention among other matters. This requires planningahead of the airplane, maintaining orientation in relationto ground objects, flying appropriate headings to followa desired ground track, and being cognizant of other airtraffic in the immediate vicinity.

Ground reference maneuvers should be flown at an alti-tude of approximately 600 to 1,000 feet AGL. Theactual altitude will depend on the speed and type of air-plane to a large extent, and the following factors shouldbe considered.

• The speed with relation to the ground should notbe so apparent that events happen too rapidly.

• The radius of the turn and the path of the airplaneover the ground should be easily noted andchanges planned and effected as circumstancesrequire.

• Drift should be easily discernable, but not tax thestudent too much in making corrections.

• Objects on the ground should appear in their pro-portion and size.

• The altitude should be low enough to render anygain or loss apparent to the student, but in no caselower than 500 feet above the highest obstruction.

During these maneuvers, both the instructor and thestudent should be alert for available forced-landingfields. The area chosen should be away from communi-ties, livestock, or groups of people to prevent possibleannoyance or hazards to others. Due to the altitudes atwhich these maneuvers are performed, there is littletime available to search for a suitable field for landingin the event the need arises.

6-1

Ch 06.qxd 5/7/04 7:35 AM Page 6-1

6-2

DRIFT AND GROUND TRACK CONTROLWhenever any object is free from the ground, it isaffected by the medium with which it is surrounded.This means that a free object will move in whateverdirection and speed that the medium moves.

For example, if a powerboat is crossing a river andthe river is still, the boat could head directly to a pointon the opposite shore and travel on a straight courseto that point without drifting. However, if the riverwere flowing swiftly, the water current would have tobe considered. That is, as the boat progresses forwardwith its own power, it must also move upstream at thesame rate the river is moving it downstream. This isaccomplished by angling the boat upstream suffi-ciently to counteract the downstream flow. If this isdone, the boat will follow the desired track acrossthe river from the departure point directly to theintended destination point. Should the boat not beheaded sufficiently upstream, it would drift with thecurrent and run aground at some point downstreamon the opposite bank. [Figure 6-1]

As soon as an airplane becomes airborne, it is free ofground friction. Its path is then affected by the air massin which it is flying; therefore, the airplane (like theboat) will not always track along the ground in theexact direction that it is headed. When flying with thelongitudinal axis of the airplane aligned with a road, itmay be noted that the airplane gets closer to or fartherfrom the road without any turn having been made. This

would indicate that the air mass is moving sideward inrelation to the airplane. Since the airplane is flyingwithin this moving body of air (wind), it moves ordrifts with the air in the same direction and speed, justlike the boat moved with the river current. [Figure 6-1]

When flying straight and level and following aselected ground track, the preferred method of cor-recting for wind drift is to head the airplane (windcorrection angle) sufficiently into the wind to causethe airplane to move forward into the wind at thesame rate the wind is moving it sideways.Depending on the wind velocity, this may require alarge wind correction angle or one of only a fewdegrees. When the drift has been neutralized, theairplane will follow the desired ground track.

To understand the need for drift correction duringflight, consider a flight with a wind velocity of 30knots from the left and 90° to the direction the airplaneis headed. After 1 hour, the body of air in which theairplane is flying will have moved 30 nautical miles(NM) to the right. Since the airplane is moving withthis body of air, it too will have drifted 30 NM to theright. In relation to the air, the airplane moved for-ward, but in relation to the ground, it moved forwardas well as 30 NM to the right.

There are times when the pilot needs to correct for driftwhile in a turn. [Figure 6-2] Throughout the turn thewind will be acting on the airplane from constantlychanging angles. The relative wind angle and speed

CURRENT CURRENT

No Current - No Drift With a current the boat driftsdownstream unless corrected.

With proper correction, boatstays on intended course.

No Wind - No Drift With any wind, the airplane driftsdownwind unless corrected.

With proper correction, airplanestays on intended course.

WIND WIND

Figure 6-1. Wind drift.

Ch 06.qxd 5/7/04 7:35 AM Page 6-2

6-3

govern the time it takes for the airplane to progressthrough any part of a turn. This is due to the constantlychanging groundspeed. When the airplane is headedinto the wind, the groundspeed is decreased; whenheaded downwind, the groundspeed is increased.Through the crosswind portion of a turn, the airplanemust be turned sufficiently into the wind to counteractdrift.

To follow a desired circular ground track, the wind cor-rection angle must be varied in a timely mannerbecause of the varying groundspeed as the turn pro-gresses. The faster the groundspeed, the faster the windcorrection angle must be established; the slower thegroundspeed, the slower the wind correction angle maybe established. It can be seen then that the steepestbank and fastest rate of turn should be made on thedownwind portion of the turn and the shallowest bankand slowest rate of turn on the upwind portion.

The principles and techniques of varying the angle ofbank to change the rate of turn and wind correctionangle for controlling wind drift during a turn are thesame for all ground track maneuvers involvingchanges in direction of flight.

When there is no wind, it should be simple to fly alonga ground track with an arc of exactly 180° and a con-stant radius because the flightpath and ground trackwould be identical. This can be demonstrated byapproaching a road at a 90° angle and, when directlyover the road, rolling into a medium-banked turn, thenmaintaining the same angle of bank throughout the180° of turn. [Figure 6-2]

To complete the turn, the rollout should be started at apoint where the wings will become level as the airplaneagain reaches the road at a 90° angle and will bedirectly over the road just as the turn is completed. Thiswould be possible only if there were absolutely nowind and if the angle of bank and the rate of turnremained constant throughout the entire maneuver.

If the turn were made with a constant angle of bankand a wind blowing directly across the road, it wouldresult in a constant radius turn through the air.However, the wind effects would cause the groundtrack to be distorted from a constant radius turn orsemicircular path. The greater the wind velocity, thegreater would be the difference between the desiredground track and the flightpath. To counteract thisdrift, the flightpath can be controlled by the pilot insuch a manner as to neutralize the effect of the wind,and cause the ground track to be a constant radiussemicircle.

The effects of wind during turns can be demonstratedafter selecting a road, railroad, or other ground refer-ence that forms a straight line parallel to the wind. Flyinto the wind directly over and along the line and thenmake a turn with a constant medium angle of bank for360° of turn. [Figure 6-3] The airplane will return to apoint directly over the line but slightly downwind fromthe starting point, the amount depending on the windvelocity and the time required to complete the turn.The path over the ground will be an elongated circle,although in reference to the air it is a perfect circle.Straight flight during the upwind segment after com-pletion of the turn is necessary to bring the airplaneback to the starting position.

20 Knot Wind

Intended ground path

Actual ground path

No Wind

Figure 6-2. Effect of wind during a turn.

Figure 6-3. Effect of wind during turns.

No Wind

Start & Finish

Ch 06.qxd 5/7/04 7:35 AM Page 6-3

6-4

A similar 360° turn may be started at a specific pointover the reference line, with the airplane headeddirectly downwind. In this demonstration, the effect ofwind during the constant banked turn will drift the air-plane to a point where the line is reintercepted, but the360° turn will be completed at a point downwind fromthe starting point.

Another reference line which lies directly crosswindmay be selected and the same procedure repeated,showing that if wind drift is not corrected the airplanewill, at the completion of the 360° turn, be headed inthe original direction but will have drifted away fromthe line a distance dependent on the amount of wind.

From these demonstrations, it can be seen where andwhy it is necessary to increase or decrease the angle ofbank and the rate of turn to achieve a desired track overthe ground. The principles and techniques involved canbe practiced and evaluated by the performance of theground track maneuvers discussed in this chapter.

RECTANGULAR COURSENormally, the first ground reference maneuver the pilotis introduced to is the rectangular course. [Figure 6-4]

The rectangular course is a training maneuver in whichthe ground track of the airplane is equidistant from allsides of a selected rectangular area on the ground. Themaneuver simulates the conditions encountered in anairport traffic pattern. While performing the maneu-ver, the altitude and airspeed should be held constant.The maneuver assists the student pilot in perfecting:

• Practical application of the turn.

• The division of attention between the flightpath,ground objects, and the handling of the airplane.

• The timing of the start of a turn so that the turnwill be fully established at a definite point overthe ground.

• The timing of the recovery from a turn so that adefinite ground track will be maintained.

• The establishing of a ground track and the deter-mination of the appropriate “crab” angle.

Like those of other ground track maneuvers, one of theobjectives is to develop division of attention betweenthe flightpath and ground references, while controllingthe airplane and watching for other aircraft in the

Turn More Than90° Rolloutwith Wind Correction Established

Complete Turnat Boundary

Turn IntoWind

Start Turn atBoundary

Start Turnat Boundary

Complete Turnat Boundary

TurnLess Than 90°

Complete Turnat Boundary

Start Turnat Boundary

No Wind Correction

Enter45° to Downwind

Exit

No Wind Correction

Turn IntoWind

Turn Less Than90° RolloutWith WIind Correction Established

Turn MoreThan 90°

Start Turn atBoundary

Complete Turnat Boundary

Tra

ck W

ith N

o W

ind

Cor

rect

ion T

rackW

ithN

oW

indC

orrection

DOWNWIND

UPWIND

CROSSWIND

BASE

Figure 6-4. Rectangular course.

Ch 06.qxd 5/7/04 7:35 AM Page 6-4

6-5

vicinity. Another objective is to develop recognition ofdrift toward or away from a line parallel to the intendedground track. This will be helpful in recognizing drifttoward or from an airport runway during the variouslegs of the airport traffic pattern.

For this maneuver, a square or rectangular field, or anarea bounded on four sides by section lines or roads(the sides of which are approximately a mile in length),should be selected well away from other air traffic. Theairplane should be flown parallel to and at a uniformdistance about one-fourth to one-half mile away fromthe field boundaries, not above the boundaries. Forbest results, the flightpath should be positioned outsidethe field boundaries just far enough that they may beeasily observed from either pilot seat by looking outthe side of the airplane. If an attempt is made to flydirectly above the edges of the field, the pilot will haveno usable reference points to start and complete theturns. The closer the track of the airplane is to the fieldboundaries, the steeper the bank necessary at the turn-ing points. Also, the pilot should be able to see theedges of the selected field while seated in a normalposition and looking out the side of the airplane duringeither a left-hand or right-hand course. The distance ofthe ground track from the edges of the field should bethe same regardless of whether the course is flown tothe left or right. All turns should be started when theairplane is abeam the corner of the field boundaries,and the bank normally should not exceed 45°. Theseshould be the determining factors in establishing thedistance from the boundaries for performing themaneuver.

Although the rectangular course may be entered fromany direction, this discussion assumes entry on adownwind.

On the downwind leg, the wind is a tailwind and resultsin an increased groundspeed. Consequently, the turnonto the next leg is entered with a fairly fast rate ofroll-in with relatively steep bank. As the turn pro-gresses, the bank angle is reduced gradually becausethe tailwind component is diminishing, resulting in adecreasing groundspeed.

During and after the turn onto this leg (the equivalentof the base leg in a traffic pattern), the wind will tendto drift the airplane away from the field boundary. Tocompensate for the drift, the amount of turn will bemore than 90°.

The rollout from this turn must be such that as thewings become level, the airplane is turned slightlytoward the field and into the wind to correct for drift.The airplane should again be the same distance fromthe field boundary and at the same altitude, as on otherlegs. The base leg should be continued until the upwind

leg boundary is being approached. Once more the pilotshould anticipate drift and turning radius. Since driftcorrection was held on the base leg, it is necessary toturn less than 90° to align the airplane parallel to theupwind leg boundary. This turn should be started witha medium bank angle with a gradual reduction to ashallow bank as the turn progresses. The rollout shouldbe timed to assure paralleling the boundary of the fieldas the wings become level.

While the airplane is on the upwind leg, the next fieldboundary should be observed as it is being approached,to plan the turn onto the crosswind leg. Since the windis a headwind on this leg, it is reducing the airplane’sgroundspeed and during the turn onto the crosswindleg will try to drift the airplane toward the field. Forthis reason, the roll-in to the turn must be slow and thebank relatively shallow to counteract this effect. As theturn progresses, the headwind component decreases,allowing the groundspeed to increase. Consequently,the bank angle and rate of turn are increased graduallyto assure that upon completion of the turn the cross-wind ground track will continue the same distancefrom the edge of the field. Completion of the turn withthe wings level should be accomplished at a pointaligned with the upwind corner of the field.

Simultaneously, as the wings are rolled level, theproper drift correction is established with the airplaneturned into the wind. This requires that the turn be lessthan a 90° change in heading. If the turn has been madeproperly, the field boundary will again appear to beone-fourth to one-half mile away. While on the cross-wind leg, the wind correction angle should be adjustedas necessary to maintain a uniform distance from thefield boundary.

As the next field boundary is being approached, thepilot should plan the turn onto the downwind leg. Sincea wind correction angle is being held into the wind andaway from the field while on the crosswind leg, thisnext turn will require a turn of more than 90°. Sincethe crosswind will become a tailwind, causing thegroundspeed to increase during this turn, the bank ini-tially should be medium and progressively increasedas the turn proceeds. To complete the turn, the rolloutmust be timed so that the wings become level at a pointaligned with the crosswind corner of the field just asthe longitudinal axis of the airplane again becomesparallel to the field boundary. The distance from thefield boundary should be the same as from the othersides of the field.

Usually, drift should not be encountered on the upwindor the downwind leg, but it may be difficult to find asituation where the wind is blowing exactly parallel tothe field boundaries. This would make it necessary touse a slight wind correction angle on all the legs. It is

Ch 06.qxd 5/7/04 7:35 AM Page 6-5

6-6

important to anticipate the turns to correct for ground-speed, drift, and turning radius. When the wind isbehind the airplane, the turn must be faster and steeper;when it is ahead of the airplane, the turn must beslower and shallower. These same techniques applywhile flying in airport traffic patterns.

Common errors in the performance of rectangularcourses are:

• Failure to adequately clear the area.

• Failure to establish proper altitude prior toentry. (Typically entering the maneuver whiledescending.)

• Failure to establish appropriate wind correctionangle resulting in drift.

• Gaining or losing altitude.

• Poor coordination. (Typically skidding in turnsfrom a downwind heading and slipping in turnsfrom an upwind heading.)

• Abrupt control usage.

• Inability to adequately divide attention betweenairplane control and maintaining ground track.

• Improper timing in beginning and recoveringfrom turns.

• Inadequate visual lookout for other aircraft.

S-TURNS ACROSS A ROADAn S-turn across a road is a practice maneuver inwhich the airplane’s ground track describes semicir-cles of equal radii on each side of a selected straightline on the ground. [Figure 6-5] The straight line maybe a road, fence, railroad, or section line that lies per-pendicular to the wind, and should be of sufficientlength for making a series of turns. A constant altitudeshould be maintained throughout the maneuver.

S-turns across a road present one of the most elemen-tary problems in the practical application of the turnand in the correction for wind drift in turns. While theapplication of this maneuver is considerably lessadvanced in some respects than the rectangular course,it is taught after the student has been introduced to thatmaneuver in order that the student may have a knowl-edge of the correction for wind drift in straight flightalong a reference line before the student attempt tocorrect for drift by playing a turn.

The objectives of S-turns across a road are to developthe ability to compensate for drift during turns, orientthe flightpath with ground references, follow anassigned ground track, arrive at specified points onassigned headings, and divide the pilot’s attention. The

SteepBank

Shallow Bank

Shallow Bank

SteepBank

Moderate Bank

Moderate Bank

Wings Level

Entry

Figure 6-5. S-Turns.

Ch 06.qxd 5/7/04 7:35 AM Page 6-6

6-7

maneuver consists of crossing the road at a 90° angleand immediately beginning a series of 180° turns ofuniform radius in opposite directions, re-crossing theroad at a 90° angle just as each 180° turn is completed.

To accomplish a constant radius ground track requiresa changing roll rate and angle of bank to establish thewind correction angle. Both will increase or decreaseas groundspeed increases or decreases.

The bank must be steepest when beginning the turn onthe downwind side of the road and must be shallowedgradually as the turn progresses from a downwindheading to an upwind heading. On the upwind side, theturn should be started with a relatively shallow bankand then gradually steepened as the airplane turns froman upwind heading to a downwind heading.

In this maneuver, the airplane should be rolled fromone bank directly into the opposite just as the referenceline on the ground is crossed.

Before starting the maneuver, a straight ground refer-ence line or road that lies 90° to the direction of thewind should be selected, then the area checked toensure that no obstructions or other aircraft are in theimmediate vicinity. The road should be approachedfrom the upwind side, at the selected altitude on adownwind heading. When directly over the road, thefirst turn should be started immediately. With the air-plane headed downwind, the groundspeed is greatestand the rate of departure from the road will be rapid;so the roll into the steep bank must be fairly rapid toattain the proper wind correction angle. This preventsthe airplane from flying too far from the road andfrom establishing a ground track of excessive radius.

During the latter portion of the first 90° of turn whenthe airplane’s heading is changing from a downwindheading to a crosswind heading, the groundspeedbecomes less and the rate of departure from the roaddecreases. The wind correction angle will be at themaximum when the airplane is headed directly cross-wind.

After turning 90°, the airplane’s heading becomesmore and more an upwind heading, the groundspeedwill decrease, and the rate of closure with the roadwill become slower. If a constant steep bank weremaintained, the airplane would turn too quickly forthe slower rate of closure, and would be headed per-pendicular to the road prematurely. Because of thedecreasing groundspeed and rate of closure whileapproaching the upwind heading, it will be necessaryto gradually shallow the bank during the remaining90° of the semicircle, so that the wind correctionangle is removed completely and the wings becomelevel as the 180° turn is completed at the moment theroad is reached.

At the instant the road is being crossed again, a turn inthe opposite direction should be started. Since the air-plane is still flying into the headwind, the groundspeedis relatively slow. Therefore, the turn will have to bestarted with a shallow bank so as to avoid an excessiverate of turn that would establish the maximum windcorrection angle too soon. The degree of bank shouldbe that which is necessary to attain the proper windcorrection angle so the ground track describes an arcthe same size as the one established on the downwindside.

Since the airplane is turning from an upwind to adownwind heading, the groundspeed will increaseand after turning 90°, the rate of closure with the roadwill increase rapidly. Consequently, the angle of bankand rate of turn must be progressively increased sothat the airplane will have turned 180° at the time itreaches the road. Again, the rollout must be timed sothe airplane is in straight-and-level flight directlyover and perpendicular to the road.

Throughout the maneuver a constant altitude shouldbe maintained, and the bank should be changingconstantly to effect a true semicircular ground track.

Often there is a tendency to increase the bank toorapidly during the initial part of the turn on theupwind side, which will prevent the completion ofthe 180° turn before re-crossing the road. This isapparent when the turn is not completed in time forthe airplane to cross the road at a perpendicularangle. To avoid this error, the pilot must visualize thedesired half circle ground track, and increase thebank during the early part of this turn. During the lat-ter part of the turn, when approaching the road, thepilot must judge the closure rate properly andincrease the bank accordingly, so as to cross the roadperpendicular to it just as the rollout is completed.

Common errors in the performance of S-turns across aroad are:

• Failure to adequately clear the area.

• Poor coordination.

• Gaining or losing altitude.

• Inability to visualize the half circle ground track.

• Poor timing in beginning and recovering fromturns.

• Faulty correction for drift.

• Inadequate visual lookout for other aircraft.

TURNS AROUND A POINTTurns around a point, as a training maneuver, is alogical extension of the principles involved in the

Ch 06.qxd 5/7/04 7:35 AM Page 6-7

6-8

performance of S-turns across a road. Its purposes asa training maneuver are:

• To further perfect turning technique.

• To perfect the ability to subconsciously controlthe airplane while dividing attention between theflightpath and ground references.

• To teach the student that the radius of a turn is adistance which is affected by the degree of bankused when turning with relation to a definiteobject.

• To develop a keen perception of altitude.

• To perfect the ability to correct for wind driftwhile in turns.

In turns around a point, the airplane is flown in two ormore complete circles of uniform radii or distancefrom a prominent ground reference point using a max-imum bank of approximately 45° while maintaining aconstant altitude.

The factors and principles of drift correction that areinvolved in S-turns are also applicable in this maneu-ver. As in other ground track maneuvers, a constantradius around a point will, if any wind exists, require aconstantly changing angle of bank and angles of wind

correction. The closer the airplane is to a direct down-wind heading where the groundspeed is greatest, thesteeper the bank and the faster the rate of turn requiredto establish the proper wind correction angle. Themore nearly it is to a direct upwind heading where thegroundspeed is least, the shallower the bank and theslower the rate of turn required to establish the properwind correction angle. It follows, then, that through-out the maneuver the bank and rate of turn must begradually varied in proportion to the groundspeed.

The point selected for turns around a point shouldbe prominent, easily distinguished by the pilot, andyet small enough to present precise reference.[Figure 6-6] Isolated trees, crossroads, or other sim-ilar small landmarks are usually suitable.

To enter turns around a point, the airplane should beflown on a downwind heading to one side of theselected point at a distance equal to the desired radiusof turn. In a high-wing airplane, the distance from thepoint must permit the pilot to see the point throughoutthe maneuver even with the wing lowered in a bank. Ifthe radius is too large, the lowered wing will block thepilot’s view of the point.

When any significant wind exists, it will be necessary toroll into the initial bank at a rapid rate so that the steep-

Steepest

Bank

Shallowest

Bank

SteeperBank

ShallowerBank

Upwind Half of Circle

Downwind Half of Circle

Figure 6-6.Turns around a point.

Ch 06.qxd 5/7/04 7:35 AM Page 6-8

6-9

est bank is attained abeam of the point when the airplaneis headed directly downwind. By entering the maneuverwhile heading directly downwind, the steepest bank canbe attained immediately. Thus, if a maximum bank of45° is desired, the initial bank will be 45° if the airplaneis at the correct distance from the point. Thereafter, thebank is shallowed gradually until the point is reachedwhere the airplane is headed directly upwind. At thispoint, the bank should be gradually steepened until thesteepest bank is again attained when heading downwindat the initial point of entry.

Just as S-turns require that the airplane be turned intothe wind in addition to varying the bank, so do turnsaround a point. During the downwind half of the circle,the airplane’s nose is progressively turned toward theinside of the circle; during the upwind half, the nose isprogressively turned toward the outside. The downwindhalf of the turn around the point may be compared to thedownwind side of the S-turn across a road; the upwindhalf of the turn around a point may be compared to theupwind side of the S-turn across a road.

As the pilot becomes experienced in performing turnsaround a point and has a good understanding of theeffects of wind drift and varying of the bank angle andwind correction angle as required, entry into themaneuver may be from any point. When entering themaneuver at a point other than downwind, however,the radius of the turn should be carefully selected, tak-ing into account the wind velocity and groundspeed sothat an excessive bank is not required later on to main-tain the proper ground track. The flight instructorshould place particular emphasis on the effect of anincorrect initial bank. This emphasis should continuein the performance of elementary eights.

Common errors in the performance of turns around apoint are:

• Failure to adequately clear the area.

• Failure to establish appropriate bank on entry.

• Failure to recognize wind drift.

• Excessive bank and/or inadequate wind correc-tion angle on the downwind side of the circleresulting in drift towards the reference point.

• Inadequate bank angle and/or excessive windcorrection angle on the upwind side of the circleresulting in drift away from the reference point.

• Skidding turns when turning from downwind tocrosswind.

• Slipping turns when turning from upwind tocrosswind.

• Gaining or losing altitude.

• Inadequate visual lookout for other aircraft.

• Inability to direct attention outside the airplanewhile maintaining precise airplane control.

ELEMENTARY EIGHTSAn “eight” is a maneuver in which the airplanedescribes a path over the ground more or less in theshape of a figure “8”. In all eights except “lazy eights”the path is horizontal as though following a markedpath over the ground. There are various types of eights,progressing from the elementary types to very difficulttypes in the advanced maneuvers. Each has its specialuse in teaching the student to solve a particularproblem of turning with relation to the Earth, or anobject on the Earth’s surface. Each type, as theyadvance in difficulty of accomplishment, furtherperfects the student’s coordination technique andrequires a higher degree of subconscious flying abil-ity. Of all the training maneuvers available to theinstructor, only eights require the progressivelyhigher degree of conscious attention to outsideobjects. However, the real importance of eights is inthe requirement for the perfection and display ofsubconscious flying.

Elementary eights, specifically eights along a road,eights across a road, and eights around pylons, arevariations of turns around a point, which use twopoints about which the airplane circles in eitherdirection. Elementary eights are designed for the fol-lowing purposes.

• To perfect turning technique.

• To develop the ability to divide attention betweenthe actual handling of controls and an outsideobjective.

• To perfect the knowledge of the effect of angle ofbank on radius of turn.

• To demonstrate how wind affects the path of theairplane over the ground.

• To gain experience in the visualization of theresults of planning before the execution of themaneuver.

• To train the student to think and plan ahead of theairplane.

EIGHTS ALONG A ROADAn eight along a road is a maneuver in which theground track consists of two complete adjacent circlesof equal radii on each side of a straight road or otherreference line on the ground. The ground track resem-bles a figure 8. [Figure 6-7 on next page]

Like the other ground reference maneuvers, itsobjective is to develop division of attention while

Ch 06.qxd 5/7/04 7:35 AM Page 6-9

6-10

compensating for drift, maintaining orientation withground references, and maintaining a constantaltitude.

Although eights along a road may be performed withthe wind blowing parallel to the road or directly acrossthe road, for simplification purposes, only the latter sit-uation is explained since the principles involved ineither case are common.

A reference line or road which is perpendicular to thewind should be selected and the airplane flown parallelto and directly above the road. Since the wind is blow-ing across the flightpath, the airplane will require somewind correction angle to stay directly above the roadduring the initial straight and level portion. Beforestarting the maneuver, the area should be checked toensure clearance of obstructions and avoidance ofother aircraft.

Usually, the first turn should be made toward a down-wind heading starting with a medium bank. Since theairplane will be turning more and more directly down-wind, the groundspeed will be gradually increasing andthe rate of departing the road will tend to becomefaster. Thus, the bank and rate of turn is increased toestablish a wind correction angle to keep the airplanefrom exceeding the desired distance from the roadwhen 180° of change in direction is completed. Thesteepest bank is attained when the airplane is headeddirectly downwind.

As the airplane completes 180° of change in direction,it will be flying parallel to and using a wind correctionangle toward the road with the wind acting directlyperpendicular to the ground track. At this point, thepilot should visualize the remaining 180° of groundtrack required to return to the same place over the roadfrom which the maneuver started.

While the turn is continued toward an upwind heading,the wind will tend to keep the airplane from reaching

the road, with a decrease in groundspeed and rate ofclosure. The rate of turn and wind correction angle aredecreased proportionately so that the road will bereached just as the 360° turn is completed. To accom-plish this, the bank is decreased so that when headeddirectly upwind, it will be at the shallowest angle. Inthe last 90° of the turn, the bank may be varied to cor-rect any previous errors in judging the returning rateand closure rate. The rollout should be timed so thatthe airplane will be straight and level over the startingpoint, with enough drift correction to hold it over theroad.

After momentarily flying straight and level along theroad, the airplane is then rolled into a medium bankturn in the opposite direction to begin the circle on theupwind side of the road. The wind will still be decreas-ing the groundspeed and trying to drift the airplaneback toward the road; therefore, the bank must bedecreased slowly during the first 90° change in direc-tion in order to reach the desired distance from theroad and attain the proper wind correction angle when180° change in direction has been completed.

As the remaining 180° of turn continues, the windbecomes more of a tailwind and increases the air-plane’s groundspeed. This causes the rate of closureto become faster; consequently, the angle of bankand rate of turn must be increased further to attainsufficient wind correction angle to keep the airplanefrom approaching the road too rapidly. The bank willbe at its steepest angle when the airplane is headeddirectly downwind.

In the last 90° of the turn, the rate of turn should bereduced to bring the airplane over the starting point onthe road. The rollout must be timed so the airplane willbe straight and level, turned into the wind, and flyingparallel to and over the road.

The measure of a student’s progress in the performanceof eights along a road is the smoothness and accuracy ofthe change in bank used to counteract drift. The soonerthe drift is detected and correction applied, the smallerwill be the required changes. The more quickly thestudent can anticipate the corrections needed, theless obvious the changes will be and the more attentioncan be diverted to the maintenance of altitude and opera-tion of the airplane.

Errors in coordination must be eliminated and a con-stant altitude maintained. Flying technique must notbe allowed to suffer from the fact that the student’sattention is diverted. This technique should improve asthe student becomes able to divide attention betweenthe operation of the airplane controls and following adesignated flightpath.

ShallowerBank

ShallowestBank Steep

Bank

ShallowestBank

SteeperBank

SteepestBank

Figure 6-7. Eights along a road.

Ch 06.qxd 5/7/04 7:35 AM Page 6-10

6-11

EIGHTS ACROSS A ROADThis maneuver is a variation of eights along a road andinvolves the same principles and techniques. The pri-mary difference is that at the completion of each loopof the figure eight, the airplane should cross an inter-section of roads or a specific point on a straight road.[Figure 6-8]

The loops should be across the road and the windshould be perpendicular to the road. Each time the roadis crossed, the crossing angle should be the same andthe wings of the airplane should be level. The eights

also may be performed by rolling from one bankimmediately to the other, directly over the road.

EIGHTS AROUND PYLONSThis training maneuver is an application of the sameprinciples and techniques of correcting for wind driftas used in turns around a point and the same objectivesas other ground track maneuvers. In this case, twopoints or pylons on the ground are used as references,and turns around each pylon are made in oppositedirections to follow a ground track in the form of afigure 8. [Figure 6-9]

SteeperBank

ShallowerBank

ShallowestBank

SteeperBank

ShallowestBank

ShallowerBank

SteepestBank

SteepestBank

Figure 6-8. Eights across a road.

SteeperBank

ShallowerBank

ShallowestBank

SteeperBank

ShallowestBank

ShallowerBank

SteepestBank

SteepestBank

Figure 6-9. Eights around pylons.

Ch 06.qxd 5/7/04 7:35 AM Page 6-11

6-12

The pattern involves flying downwind between thepylons and upwind outside of the pylons. It mayinclude a short period of straight-and-level flight whileproceeding diagonally from one pylon to the other.

The pylons selected should be on a line 90° to thedirection of the wind and should be in an area awayfrom communities, livestock, or groups of people, toavoid possible annoyance or hazards to others. Thearea selected should be clear of hazardous obstructionsand other air traffic. Throughout the maneuver a con-stant altitude of at least 500 feet above the groundshould be maintained.

The eight should be started with the airplane on adownwind heading when passing between the pylons.The distance between the pylons and the wind velocitywill determine the initial angle of bank required tomaintain a constant radius from the pylons during eachturn. The steepest banks will be necessary just aftereach turn entry and just before the rollout from eachturn where the airplane is headed downwind and thegroundspeed is greatest; the shallowest banks will bewhen the airplane is headed directly upwind and thegroundspeed is least.

The rate of bank change will depend on the windvelocity, the same as it does in S-turns and turnsaround a point, and the bank will be changing contin-uously during the turns. The adjustment of the bankangle should be gradual from the steepest bank to theshallowest bank as the airplane progressively headsinto the wind, followed by a gradual increase until thesteepest bank is again reached just prior to rollout. Ifthe airplane is to proceed diagonally from one turn tothe other, the rollout from each turn must be completedon the proper heading with sufficient wind correctionangle to ensure that after brief straight-and-level flight,the airplane will arrive at the point where a turn of thesame radius can be made around the other pylon. Thestraight-and-level flight segments must be tangent toboth circular patterns.

Common errors in the performance of elementaryeights are:

• Failure to adequately clear the area.

• Poor choice of ground reference points.

• Improper maneuver entry considering winddirection and ground reference points.

• Incorrect initial bank.

• Poor coordination during turns.

• Gaining or losing altitude.

• Loss of orientation.

• Abrupt rather than smooth changes in bank angleto counteract wind drift in turns.

• Failure to anticipate needed drift correction.

• Failure to apply needed drift correction in atimely manner.

• Failure to roll out of turns on proper heading.

• Inability to divide attention between referencepoints on the ground, airplane control, and scan-ning for other aircraft.

EIGHTS-ON-PYLONS (PYLON EIGHTS)The pylon eight is the most advanced and most diffi-cult of the low altitude flight training maneuvers.Because of the various techniques involved, the pyloneight is unsurpassed for teaching, developing, and test-ing subconscious control of the airplane.

As the pylon eight is essentially an advancedmaneuver in which the pilot’s attention is directedat maintaining a pivotal position on a selected pylon,with a minimum of attention within the cockpit, itshould not be introduced until the instructor is assuredthat the student has a complete grasp of the fundamentals.Thus, the prerequisites are the ability to make a coordi-nated turn without gain or loss of altitude, excellent feel ofthe airplane, stall recognition, relaxation with low altitudemaneuvering, and an absence of the error of overconcentration.

Like eights around pylons, this training maneuver alsoinvolves flying the airplane in circular paths, alter-nately left and right, in the form of a figure 8 aroundtwo selected points or pylons on the ground. Unlikeeights around pylons, however, no attempt is made tomaintain a uniform distance from the pylon. In eights-on-pylons, the distance from the pylons varies if thereis any wind. Instead, the airplane is flown at such aprecise altitude and airspeed that a line parallel to theairplane’s lateral axis, and extending from the pilot’seye, appears to pivot on each of the pylons. [Figure 6-10] Also, unlike eights around pylons, in the perform-ance of eights-on-pylons the degree of bank increasesas the distance from the pylon decreases.

The altitude that is appropriate for the airplane beingflown is called the pivotal altitude and is governed bythe groundspeed. While not truly a ground trackmaneuver as were the preceding maneuvers, the objec-tive is similar—to develop the ability to maneuver theairplane accurately while dividing one’s attentionbetween the flightpath and the selected points on theground.

In explaining the performance of eights-on-pylons, theterm “wingtip” is frequently considered as being syn-onymous with the proper reference line, or pivotpoint on the airplane. This interpretation is not

Ch 06.qxd 5/7/04 7:35 AM Page 6-12

6-13

always correct. High-wing, low-wing, sweptwing, andtapered wing airplanes, as well as those with tandem orside-by-side seating, will all present different angles fromthe pilot’s eye to the wingtip. [Figure 6-11] Therefore, in

the correct performance of eights-on-pylons, as in othermaneuvers requiring a lateral reference, the pilot shoulduse a sighting reference line that, from eye level, parallelsthe lateral axis of the airplane.

Closest tothe Pylon

LowestGroundspeedLowest PivotalAltitude

High GroundspeedHigh Pivotal Altitude

Entry

Figure 6-10. Eights-on-pylons.

Figure 6-11. Line of sight.

Lateral Axis

Line of Sight

Lateral Axis

Line of Sight

Ch 06.qxd 5/7/04 7:35 AM Page 6-13

6-14

The sighting point or line, while not necessarily on thewingtip itself, may be positioned in relation to thewingtip (ahead, behind, above, or below), but eventhen it will differ for each pilot, and from each seat inthe airplane. This is especially true in tandem (fore andaft) seat airplanes. In side-by-side type airplanes, therewill be very little variation in the sighting lines for dif-ferent persons if those persons are seated so that theeyes of each are at approximately the same level.

An explanation of the pivotal altitude is also essential.There is a specific altitude at which, when the airplaneturns at a given groundspeed, a projection of the sight-ing reference line to the selected point on the groundwill appear to pivot on that point. Since different air-planes fly at different airspeeds, the groundspeed willbe different. Therefore, each airplane will have its ownpivotal altitude. [Figure 6-12] The pivotal altitude doesnot vary with the angle of bank being used unless thebank is steep enough to affect the groundspeed. A ruleof thumb for estimating pivotal altitude in calm wind isto square the true airspeed and divide by 15 for milesper hour (m.p.h.) or 11.3 for knots.

Distance from the pylon affects the angle of bank.At any altitude above that pivotal altitude, the pro-jected reference line will appear to move rearwardin a circular path in relation to the pylon.Conversely, when the airplane is below the pivotalaltitude, the projected reference line will appear tomove forward in a circular path. [Figure 6-13]

To demonstrate this, the airplane is flown at normalcruising speed, and at an altitude estimated to be belowthe proper pivotal altitude, and then placed in amedium-banked turn. It will be seen that the projectedreference line of sight appears to move forward alongthe ground (pylon moves back) as the airplane turns.

A climb is then made to an altitude well above the piv-otal altitude, and when the airplane is again at normal

cruising speed, it is placed in a medium-banked turn.At this higher altitude, the projected reference line ofsight now appears to move backward across theground (pylon moves forward) in a direction oppositethat of flight.

After the high altitude extreme has been demonstrated,the power is reduced, and a descent at cruising speedbegun in a continuing medium bank around the pylon.The apparent backward travel of the projected refer-ence line with respect to the pylon will slow down asaltitude is lost, stop for an instant, then start to reverseitself, and would move forward if the descent wereallowed to continue below the pivotal altitude.

The altitude at which the line of sight apparentlyceased to move across the ground was the pivotalaltitude. If the airplane descended below the pivotalaltitude, power should be added to maintain airspeedwhile altitude is regained to the point at which theprojected reference line moves neither backward norforward but actually pivots on the pylon. In this waythe pilot can determine the pivotal altitude of the air-plane.

The pivotal altitude is critical and will change withvariations in groundspeed. Since the headingsthroughout the turns continually vary from directlydownwind to directly upwind, the groundspeed willconstantly change. This will result in the proper piv-otal altitude varying slightly throughout the eight.Therefore, adjustment is made for this by climbing ordescending, as necessary, to hold the reference line orpoint on the pylons. This change in altitude will bedependent on how much the wind affects the ground-speed.

The instructor should emphasize that the elevators arethe primary control for holding the pylons. Even a veryslight variation in altitude effects a double correction,since in losing altitude, speed is gained, and even aslight climb reduces the airspeed. This variation in alti-tude, although important in holding the pylon, in mostcases will be so slight as to be barely perceptible on asensitive altimeter.

Before beginning the maneuver, the pilot should selecttwo points on the ground along a line which lies 90° tothe direction of the wind. The area in which themaneuver is to be performed should be checked forobstructions and any other air traffic, and it should belocated where a disturbance to groups of people, live-stock, or communities will not result.

The selection of proper pylons is of importance togood eights-on-pylons. They should be sufficientlyprominent to be readily seen by the pilot when com-pleting the turn around one pylon and heading for thenext, and should be adequately spaced to provide time

AIRSPEED

KNOTS MPH

APPROXIMATEPIVOTAL ALTITUDE

87

91

96

100

104

109

113

100

105

110

115

120

125

130

670

735

810

885

960

1050

1130

Figure 6-12. Speed vs. pivotal altitude.

Ch 06.qxd 5/7/04 7:35 AM Page 6-14

6-15

for planning the turns and yet not cause unnecessarystraight-and-level flight between the pylons. Theselected pylons should also be at the same elevation,since differences of over a very few feet will necessi-tate climbing or descending between each turn.

For uniformity, the eight is usually begun by flyingdiagonally crosswind between the pylons to a pointdownwind from the first pylon so that the first turncan be made into the wind. As the airplaneapproaches a position where the pylon appears to bejust ahead of the wingtip, the turn should be startedby lowering the upwind wing to place the pilot’s lineof sight reference on the pylon. As the turn is contin-ued, the line of sight reference can be held on thepylon by gradually increasing the bank. The referenceline should appear to pivot on the pylon. As the air-plane heads into the wind, the groundspeeddecreases; consequently, the pivotal altitude is lowerand the airplane must descend to hold the referenceline on the pylon. As the turn progresses on theupwind side of the pylon, the wind becomes more ofa crosswind. Since a constant distance from the pylon

is not required on this maneuver, no correction tocounteract drifting should be applied during the turns.

If the reference line appears to move ahead of thepylon, the pilot should increase altitude. If the refer-ence line appears to move behind the pylon, the pilotshould decrease altitude. Varying rudder pressure toyaw the airplane and force the wing and referenceline forward or backward to the pylon is a dangeroustechnique and must not be attempted.

As the airplane turns toward a downwind heading,the rollout from the turn should be started to allowthe airplane to proceed diagonally to a point on thedownwind side of the second pylon. The rolloutmust be completed in the proper wind correctionangle to correct for wind drift, so that the airplanewill arrive at a point downwind from the secondpylon the same distance it was from the first pylonat the beginning of the maneuver.

Upon reaching that point, a turn is started in the oppositedirection by lowering the upwind wing to again placethe pilot’s line of sight reference on the pylon. The turn

Too High

Pivotal Altitude

Too Low

Figure 6-13. Effect of different altitudes on pivotal altitude.

Ch 06.qxd 5/10/04 5:55 AM Page 6-15

6-16

is then continued just as in the turn around the firstpylon but in the opposite direction.

With prompt correction, and a very fine controltouch, it should be possible to hold the projection ofthe reference line directly on the pylon even in a stiffwind. Corrections for temporary variations, such asthose caused by gusts or inattention, may be made byshallowing the bank to fly relatively straight to bringforward a lagging wing, or by steepening the banktemporarily to turn back a wing which has creptahead. With practice, these corrections will becomeso slight as to be barely noticeable. These variationsare apparent from the movement of the wingtips longbefore they are discernable on the altimeter.

Pylon eights are performed at bank angles rangingfrom shallow to steep. [Figure 6-14] The studentshould understand that the bank chosen will not alterthe pivotal altitude. As proficiency is gained, theinstructor should increase the complexity of themaneuver by directing the student to enter at a distancefrom the pylon that will result in a specific bank angleat the steepest point in the pylon turn.

The most common error in attempting to hold a pylonis incorrect use of the rudder. When the projection ofthe reference line moves forward with respect to the

pylon, many pilots will tend to press the inside rudderto yaw the wing backward. When the reference linemoves behind the pylon, they will press the outsiderudder to yaw the wing forward. The rudder is to beused only as a coordination control.

Other common errors in the performance of eights-on-pylons (pylon eights) are:

• Failure to adequately clear the area.

• Skidding or slipping in turns (whether trying tohold the pylon with rudder or not).

• Excessive gain or loss of altitude.

• Over concentration on the pylon and failure toobserve traffic.

• Poor choice of pylons.

• Not entering the pylon turns into the wind.

• Failure to assume a heading when flyingbetween pylons that will compensate sufficientlyfor drift.

• Failure to time the bank so that the turn entry iscompleted with the pylon in position.

• Abrupt control usage.

• Inability to select pivotal altitude.

Pylon

PivotalAltitude

60˚ ˚ ˚

Figure 6-14. Bank angle vs. pivotal altitude.

Ch 06.qxd 5/7/04 7:35 AM Page 6-16

AIRPORT TRAFFICPATTERNS AND OPERATIONSJust as roads and streets are needed in order to utilizeautomobiles, airports or airstrips are needed to utilizeairplanes. Every flight begins and ends at an airport orother suitable landing field. For that reason, it isessential that the pilot learn the traffic rules, trafficprocedures, and traffic pattern layouts that may be inuse at various airports.

When an automobile is driven on congested city streets,it can be brought to a stop to give way to conflicting traf-fic; however, an airplane can only be slowed down.Consequently, specific traffic patterns and traffic controlprocedures have been established at designated airports.The traffic patterns provide specific routes for takeoffs,departures, arrivals, and landings. The exact nature ofeach airport traffic pattern is dependent on the runway inuse, wind conditions, obstructions, and other factors.

Control towers and radar facilities provide a means ofadjusting the flow of arriving and departing aircraft,and render assistance to pilots in busy terminal areas.Airport lighting and runway marking systems are usedfrequently to alert pilots to abnormal conditions andhazards, so arrivals and departures can be made safely.

Airports vary in complexity from small grass or sodstrips to major terminals having many paved runwaysand taxiways. Regardless of the type of airport, thepilot must know and abide by the rules and generaloperating procedures applicable to the airport beingused. These rules and procedures are based not only onlogic or common sense, but also on courtesy, and theirobjective is to keep air traffic moving with maximumsafety and efficiency. The use of any traffic pattern,service, or procedure does not alter the responsibilityof pilots to see and avoid other aircraft.

STANDARD AIRPORTTRAFFIC PATTERNSTo assure that air traffic flows into and out of an airportin an orderly manner, an airport traffic pattern is estab-lished appropriate to the local conditions, including thedirection and placement of the pattern, the altitude tobe flown, and the procedures for entering and leavingthe pattern. Unless the airport displays approved visualmarkings indicating that turns should be made to the

right, the pilot should make all turns in the pattern tothe left.

When operating at an airport with an operating controltower, the pilot receives, by radio, a clearance toapproach or depart, as well as pertinent informationabout the traffic pattern. If there is not a control tower,it is the pilot’s responsibility to determine the directionof the traffic pattern, to comply with the appropriatetraffic rules, and to display common courtesy towardother pilots operating in the area.

The pilot is not expected to have extensive knowledgeof all traffic patterns at all airports, but if the pilot isfamiliar with the basic rectangular pattern, it will beeasy to make proper approaches and departures frommost airports, regardless of whether they have controltowers. At airports with operating control towers, thetower operator may instruct pilots to enter the trafficpattern at any point or to make a straight-in approachwithout flying the usual rectangular pattern. Manyother deviations are possible if the tower operator andthe pilot work together in an effort to keep trafficmoving smoothly. Jets or heavy airplanes willfrequently be flying wider and/or higher patterns thanlighter airplanes, and in many cases will make astraight-in approach for landing.

Compliance with the basic rectangular traffic patternreduces the possibility of conflicts at airports withoutan operating control tower. It is imperative that the pilotform the habit of exercising constant vigilance in thevicinity of airports even though the air traffic appearsto be light.

The standard rectangular traffic pattern is illustrated infigure 7-1 (on next page). The traffic pattern altitude isusually 1,000 feet above the elevation of the airport sur-face. The use of a common altitude at a given airport is thekey factor in minimizing the risk of collisions at airportswithout operating control towers.

It is recommended that while operating in the trafficpattern at an airport without an operating controltower the pilot maintain an airspeed that conformswith the limits established by Title 14 of the Code ofFederal Regulations (14 CFR) part 91 for such an air-port: no more than 200 knots (230 miles per hour(m.p.h.)). In any case, the speed should be adjusted,

7-1

Ch 07.qxd 5/7/04 7:54 AM Page 7-1

7-2

Figure 7-1.Traffic patterns.

LEFT-HAND TRAFFIC PATTERN

Entry

Crosswind

Departure

Final

Base

Downwind

RIGHT-HAND TRAFFIC PATTERN

Crosswind

Final

Base

Downwind

Entry

Departure

Ch 07.qxd 5/7/04 7:54 AM Page 7-2

7-3

when practicable, so that it is compatible with thespeed of other airplanes in the pattern.

When entering the traffic pattern at an airport withoutan operating control tower, inbound pilots are expectedto observe other aircraft already in the pattern and toconform to the traffic pattern in use. If other aircraftare not in the pattern, then traffic indicators on theground and wind indicators must be checked to deter-mine which runway and traffic pattern direction shouldbe used. [Figure 7-2] Many airports have L-shapedtraffic pattern indicators displayed with a segmentedcircle adjacent to the runway. The short member of theL shows the direction in which the traffic pattern turnsshould be made when using the runway parallel to thelong member. These indicators should be checkedwhile at a distance well away from any pattern thatmight be in use, or while at a safe height well abovegenerally used pattern altitudes. When the proper traf-fic pattern direction has been determined, the pilotshould then proceed to a point well clear of the patternbefore descending to the pattern altitude.

When approaching an airport for landing, the traffic pat-tern should be entered at a 45° angle to the downwindleg, headed toward a point abeam of the midpoint of therunway to be used for landing. Arriving airplanes shouldbe at the proper traffic pattern altitude before enteringthe pattern, and should stay clear of the traffic flow untilestablished on the entry leg. Entries into traffic patternswhile descending create specific collision hazards andshould always be avoided.

The entry leg should be of sufficient length to providea clear view of the entire traffic pattern, and to allowthe pilot adequate time for planning the intended pathin the pattern and the landing approach.

The downwind leg is a course flown parallel to thelanding runway, but in a direction opposite to theintended landing direction. This leg should be

approximately 1/2 to 1 mile out from the landing run-way, and at the specified traffic pattern altitude.During this leg, the before landing check should becompleted and the landing gear extended ifretractable. Pattern altitude should be maintaineduntil abeam the approach end of the landing runway.At this point, power should be reduced and a descentbegun. The downwind leg continues past a pointabeam the approach end of the runway to a pointapproximately 45° from the approach end of the run-way, and a medium bank turn is made onto the baseleg.

The base leg is the transitional part of the traffic pat-tern between the downwind leg and the final approachleg. Depending on the wind condition, it is establishedat a sufficient distance from the approach end of thelanding runway to permit a gradual descent to theintended touchdown point. The ground track of the air-plane while on the base leg should be perpendicular tothe extended centerline of the landing runway,although the longitudinal axis of the airplane may notbe aligned with the ground track when it is necessaryto turn into the wind to counteract drift. While on thebase leg, the pilot must ensure, before turning onto thefinal approach, that there is no danger of colliding withanother aircraft that may be already on the finalapproach.

The final approach leg is a descending flightpath start-ing from the completion of the base-to-final turn andextending to the point of touchdown. This is probablythe most important leg of the entire pattern, becausehere the pilot’s judgment and procedures must be thesharpest to accurately control the airspeed and descentangle while approaching the intended touchdownpoint.

As stipulated in 14 CFR part 91, aircraft while onfinal approach to land or while landing, have theright-of-way over other aircraft in flight or operatingon the surface. When two or more aircraft areapproaching an airport for the purpose of landing, theaircraft at the lower altitude has the right-of-way.Pilots should not take advantage of this rule to cut infront of another aircraft that is on final approach toland, or to overtake that aircraft.

The upwind leg is a course flown parallel to the land-ing runway, but in the same direction to the intendedlanding direction. The upwind leg continues past apoint abeam of the departure end of the runway towhere a medium bank 90° turn is made onto thecrosswind leg.

The upwind leg is also the transitional part of the traf-fic pattern when on the final approach and a go-aroundis initiated and climb attitude is established. When aFigure 7-2.Traffic pattern indicators.

Windsock

Segmented Circle

Traffic Pattern Indicator(indicates location of base leg)

Ch 07.qxd 5/7/04 7:54 AM Page 7-3

7-4

safe altitude is attained, the pilot should commence ashallow bank turn to the upwind side of the airport.This will allow better visibility of the runway fordeparting aircraft.

The departure leg of the rectangular pattern is astraight course aligned with, and leading from, thetakeoff runway. This leg begins at the point the air-plane leaves the ground and continues until the 90°turn onto the crosswind leg is started.

On the departure leg after takeoff, the pilot should con-tinue climbing straight ahead, and, if remaining in thetraffic pattern, commence a turn to the crosswind legbeyond the departure end of the runway within 300 feetof pattern altitude. If departing the traffic pattern, con-tinue straight out or exit with a 45° turn (to the leftwhen in a left-hand traffic pattern; to the right when in

a right-hand traffic pattern) beyond the departure endof the runway after reaching pattern altitude.

The crosswind leg is the part of the rectangular patternthat is horizontally perpendicular to the extended cen-terline of the takeoff runway and is entered by makingapproximately a 90° turn from the upwind leg. On thecrosswind leg, the airplane proceeds to the downwindleg position.

Since in most cases the takeoff is made into the wind,the wind will now be approximately perpendicular tothe airplane’s flightpath. As a result, the airplane willhave to be turned or headed slightly into the windwhile on the crosswind leg to maintain a ground trackthat is perpendicular to the runway centerline exten-sion.

Additional information on airport operations can befound in the Aeronautical Information Manual (AIM).

Ch 07.qxd 5/7/04 7:54 AM Page 7-4

NORMAL APPROACH AND LANDINGA normal approach and landing involves the use ofprocedures for what is considered a normal situation;that is, when engine power is available, the wind islight or the final approach is made directly into thewind, the final approach path has no obstacles, and thelanding surface is firm and of ample length togradually bring the airplane to a stop. The selectedlanding point should be beyond the runway’s approachthreshold but within the first one-third portion ofthe runway.

The factors involved and the procedures described forthe normal approach and landing also have applicationsto the other-than-normal approaches and landingswhich are discussed later in this chapter. This being thecase, the principles of normal operations are explainedfirst and must be understood before proceeding to themore complex operations. So that the pilot may betterunderstand the factors that will influence judgment andprocedures, that last part of the approach pattern andthe actual landing will be divided into five phases: thebase leg, the final approach, the roundout, thetouchdown, and the after-landing roll.

It must be remembered that the manufacturer’srecommended procedures, including airplaneconfiguration and airspeeds, and other informationrelevant to approaches and landings in a specific makeand model airplane are contained in the FAA-approvedAirplane Flight Manual and/or Pilot’s OperatingHandbook (AFM/POH) for that airplane. If any of theinformation in this chapter differs from the airplanemanufacturer’s recommendations as contained inthe AFM/POH, the airplane manufacturer’srecommendations take precedence.

BASE LEGThe placement of the base leg is one of the moreimportant judgments made by the pilot in any landingapproach. [Figure 8-1] The pilot must accurately judgethe altitude and distance from which a gradual descentwill result in landing at the desired spot. The distancewill depend on the altitude of the base leg, the effect ofwind, and the amount of wing flaps used. When there isa strong wind on final approach or the flaps will beused to produce a steep angle of descent, the base legmust be positioned closer to the approach end of therunway than would be required with a light wind or no

Figure 8-1. Base leg and final approach.

8-1

Ch 08.qxd 5/7/04 8:08 AM Page 8-1

flaps. Normally, the landing gear should be extendedand the before landing check completed priorto reaching the base leg.

After turning onto the base leg, the pilot should startthe descent with reduced power and airspeed ofapproximately 1.4 VSO. (VSO—the stalling speedwith power off, landing gears and flaps down.) Forexample, if VSO is 60 knots, the speed should be 1.4times 60, or 84 knots. Landing flaps may be partiallylowered, if desired, at this time. Full flaps are notrecommended until the final approach is established.Drift correction should be established andmaintained to follow a ground track perpendicularto the extension of the centerline of the runway onwhich the landing is to be made. Since the finalapproach and landing will normally be made intothe wind, there will be somewhat of a crosswindduring the base leg. This requires that the airplane beangled sufficiently into the wind to prevent driftingfarther away from the intended landing spot.

The base leg should be continued to the point where amedium to shallow-banked turn will align theairplane’s path directly with the centerline of thelanding runway. This descending turn should becompleted at a safe altitude that will be dependentupon the height of the terrain and any obstructionsalong the ground track. The turn to the final approachshould also be sufficiently above the airport elevationto permit a final approach long enough for the pilot toaccurately estimate the resultant point of touchdown,while maintaining the proper approach airspeed. Thiswill require careful planning as to the starting pointand the radius of the turn. Normally, it is recommendedthat the angle of bank not exceed a medium bankbecause the steeper the angle of bank, the higher theairspeed at which the airplane stalls. Since the base-to-final turn is made at a relatively low altitude, it isimportant that a stall not occur at this point. If anextremely steep bank is needed to preventovershooting the proper final approach path, it is

advisable to discontinue the approach, go around, andplan to start the turn earlier on the next approach ratherthan risk a hazardous situation.

FINAL APPROACHAfter the base-to-final approach turn is completed, thelongitudinal axis of the airplane should be aligned withthe centerline of the runway or landing surface, so thatdrift (if any) will be recognized immediately. On anormal approach, with no wind drift, the longitudinalaxis should be kept aligned with the runway centerlinethroughout the approach and landing. (The proper wayto correct for a crosswind will be explained under thesection, Crosswind Approach and Landing. For now,only an approach and landing where the wind isstraight down the runway will be discussed.)

After aligning the airplane with the runway centerline,the final flap setting should be completed and the pitchattitude adjusted as required for the desired rate ofdescent. Slight adjustments in pitch and power maybe necessary to maintain the descent attitude and thedesired approach airspeed. In the absence of themanufacturer’s recommended airspeed, a speedequal to 1.3 VSO should be used. If VSO is 60 knots,the speed should be 78 knots. When the pitchattitude and airspeed have been stabilized, theairplane should be retrimmed to relieve thepressures being held on the controls.

The descent angle should be controlled throughout theapproach so that the airplane will land in the centerof the first third of the runway. The descent angle isaffected by all four fundamental forces that act on anairplane (lift, drag, thrust, and weight). If all theforces are constant, the descent angle will be constantin a no-wind condition. The pilot can control theseforces by adjusting the airspeed, attitude, power, anddrag (flaps or forward slip). The wind also plays aprominent part in the gliding distance over theground [Figure 8-2]; naturally, the pilot does not havecontrol over the wind but may correct for its effecton the airplane’s descent by appropriate pitch andpower adjustments.

Increased Airspeed Flightpath

Normal Best Glide SpeedFlightpath

Figure 8-2. Effect of headwind on final approach.

8-2

Ch 08.qxd 5/7/04 8:08 AM Page 8-2

8-3

Considering the factors that affect the descent angle onthe final approach, for all practical purposes at a givenpitch attitude there is only one power setting for oneairspeed, one flap setting, and one wind condition.A change in any one of these variables will requirean appropriate coordinated change in the other con-trollable variables. For example, if the pitch attitudeis raised too high without an increase of power, theairplane will settle very rapidly and touch downshort of the desired spot. For this reason, the pilotshould never try to stretch a glide by applying back-elevator pressure alone to reach the desired landingspot. This will shorten the gliding distance if power isnot added simultaneously. The proper angle of descentand airspeed should be maintained by coordinatingpitch attitude changes and power changes.

The objective of a good final approach is to descend atan angle and airspeed that will permit the airplane toreach the desired touchdown point at an airspeedwhich will result in minimum floating just beforetouchdown; in essence, a semi-stalled condition. Toaccomplish this, it is essential that both the descentangle and the airspeed be accurately controlled. Sinceon a normal approach the power setting is not fixed asin a power-off approach, the power and pitch attitudeshould be adjusted simultaneously as necessary, tocontrol the airspeed, and the descent angle, or to attainthe desired altitudes along the approach path. By low-ering the nose and reducing power to keep approachairspeed constant, a descent at a higher rate can be

made to correct for being too high in the approach.This is one reason for performing approaches with par-tial power; if the approach is too high, merely lowerthe nose and reduce the power. When the approach istoo low, add power and raise the nose.

USE OF FLAPSThe lift/drag factors may also be varied by the pilot toadjust the descent through the use of landing flaps.[Figures 8-3 and 8-4] Flap extension during landingsprovides several advantages by:

• Producing greater lift and permitting lowerlanding speed.

• Producing greater drag, permitting a steepdescent angle without airspeed increase.

• Reducing the length of the landing roll.

Flap extension has a definite effect on the airplane’spitch behavior. The increased camber from flap deflec-tion produces lift primarily on the rear portion of thewing. This produces a nosedown pitching moment;however, the change in tail loads from the downwashdeflected by the flaps over the horizontal tail has asignificant influence on the pitching moment.Consequently, pitch behavior depends on the designfeatures of the particular airplane.

Flap deflection of up to 15° primarily produces lift withminimal drag. The airplane has a tendency to balloon

No FlapsHalf Flaps

Full Flaps

With: Constant Airspeed Constant Power

Flatter Descent Angle

Steeper Descent Angle

With: Constant Airspeed Constant Power

No Flaps Half Flaps Full Flaps

Figure 8-3. Effect of flaps on the landing point.

Figure 8-4. Effect of flaps on the approach angle.

Ch 08.qxd 5/7/04 8:08 AM Page 8-3

up with initial flap deflection because of the liftincrease. The nosedown pitching moment, however,tends to offset the balloon. Flap deflection beyond 15°produces a large increase in drag. Also, deflectionbeyond 15° produces a significant noseup pitchingmoment in high-wing airplanes because the resultingdownwash increases the airflow over the horizontal tail.

The time of flap extension and the degree of deflectionare related. Large flap deflections at one single point inthe landing pattern produce large lift changes thatrequire significant pitch and power changes in order tomaintain airspeed and descent angle. Consequently, thedeflection of flaps at certain positions in the landingpattern has definite advantages. Incremental deflectionof flaps on downwind, base leg, and final approachallow smaller adjustment of pitch and power comparedto extension of full flaps all at one time.

When the flaps are lowered, the airspeed will decreaseunless the power is increased or the pitch attitudelowered. On final approach, therefore, the pilot mustestimate where the airplane will land throughdiscerning judgment of the descent angle. If it appearsthat the airplane is going to overshoot the desiredlanding spot, more flaps may be used if not fullyextended or the power reduced further, and the pitchattitude lowered. This will result in a steeper approach.If the desired landing spot is being undershot and ashallower approach is needed, both power and pitchattitude should be increased to readjust the descentangle. Never retract the flaps to correct for undershoot-ing since that will suddenly decrease the lift and causethe airplane to sink even more rapidly.

The airplane must be retrimmed on the final approachto compensate for the change in aerodynamic forces.With the reduced power and with a slower airspeed,the airflow produces less lift on the wings and lessdownward force on the horizontal stabilizer, resultingin a significant nosedown tendency. The elevator mustthen be trimmed more noseup.

It will be found that the roundout, touchdown, andlanding roll are much easier to accomplish when theyare preceded by a proper final approach with precisecontrol of airspeed, attitude, power, and drag resultingin a stabilized descent angle.

ESTIMATING HEIGHT AND MOVEMENTDuring the approach, roundout, and touchdown, visionis of prime importance. To provide a wide scope ofvision and to foster good judgment of height andmovement, the pilot’s head should assume a natural,straight-ahead position. The pilot’s visual focus shouldnot be fixed on any one side or any one spot ahead ofthe airplane, but should be changing slowly from apoint just over the airplane’s nose to the desiredtouchdown zone and back again, while maintaining a

deliberate awareness of distance from either side ofthe runway within the pilot’s peripheral field of vision.

Accurate estimation of distance is, besides being amatter of practice, dependent upon how clearly objectsare seen; it requires that the vision be focused properlyin order that the important objects stand out as clearlyas possible.

Speed blurs objects at close range. For example,most everyone has noted this in an automobilemoving at high speed. Nearby objects seem to mergetogether in a blur, while objects farther away standout clearly. The driver subconsciously focuses theeyes sufficiently far ahead of the automobile to seeobjects distinctly.

The distance at which the pilot’s vision is focusedshould be proportionate to the speed at which theairplane is traveling over the ground. Thus, as speed isreduced during the roundout, the distance ahead of theairplane at which it is possible to focus should bebrought closer accordingly.

If the pilot attempts to focus on a reference that is tooclose or looks directly down, the reference willbecome blurred, [Figure 8-5] and the reaction will beeither too abrupt or too late. In this case, the pilot’stendency will be to overcontrol, round out high, andmake full-stall, drop-in landings. When the pilotfocuses too far ahead, accuracy in judging thecloseness of the ground is lost and the consequentreaction will be too slow since there will not appear tobe a necessity for action. This will result in theairplane flying into the ground nose first. The changeof visual focus from a long distance to a short distancerequires a definite time interval and even though thetime is brief, the airplane’s speed during this interval issuch that the airplane travels an appreciable distance,both forward and downward toward the ground.

Figure 8-5. Focusing too close blurs vision.

If the focus is changed gradually, being brought pro-gressively closer as speed is reduced, the time interval

8-4

Ch 08.qxd 5/7/04 8:08 AM Page 8-4

8-5

and the pilot’s reaction will be reduced, and the wholelanding process smoothed out.

ROUNDOUT (FLARE)The roundout is a slow, smooth transition from a nor-mal approach attitude to a landing attitude, graduallyrounding out the flightpath to one that is parallel with,and within a very few inches above, the runway. Whenthe airplane, in a normal descent, approaches withinwhat appears to be 10 to 20 feet above the ground, theroundout or flare should be started, and once startedshould be a continuous process until the airplanetouches down on the ground.

As the airplane reaches a height above the groundwhere a timely change can be made into the properlanding attitude, back-elevator pressure should begradually applied to slowly increase the pitch attitudeand angle of attack. [Figure 8-6] This will cause theairplane’s nose to gradually rise toward the desiredlanding attitude. The angle of attack should beincreased at a rate that will allow the airplane to con-tinue settling slowly as forward speed decreases.

When the angle of attack is increased, the lift is momen-tarily increased, which decreases the rate of descent.Since power normally is reduced to idle during theroundout, the airspeed will also gradually decrease.This will cause lift to decrease again, and it must becontrolled by raising the nose and further increasing theangle of attack. During the roundout, the airspeed isbeing decreased to touchdown speed while the lift is

being controlled so the airplane will settle gently ontothe landing surface. The roundout should be executedat a rate that the proper landing attitude and the propertouchdown airspeed are attained simultaneously just asthe wheels contact the landing surface.

The rate at which the roundout is executed depends onthe airplane’s height above the ground, the rate ofdescent, and the pitch attitude. A roundout startedexcessively high must be executed more slowly thanone from a lower height to allow the airplane todescend to the ground while the proper landing attitudeis being established. The rate of rounding out must alsobe proportionate to the rate of closure with the ground.When the airplane appears to be descending veryslowly, the increase in pitch attitude must be made at acorrespondingly slow rate.

Visual cues are important in flaring at the proper alti-tude and maintaining the wheels a few inches abovethe runway until eventual touchdown. Flare cues areprimarily dependent on the angle at which the pilot’scentral vision intersects the ground (or runway) aheadand slightly to the side. Proper depth perception is afactor in a successful flare, but the visual cues usedmost are those related to changes in runway or terrainperspective and to changes in the size of familiarobjects near the landing area such as fences, bushes,trees, hangars, and even sod or runway texture. Thepilot should direct central vision at a shallow down-ward angle of from 10° to 15° toward the runway asthe roundout/flare is initiated. [Figure 8-7]Maintaining the same viewing angle causes the point

IncreaseAngle ofAttack

IncreaseAngle ofAttack

IncreaseAngle ofAttack

78 Knots

70 Knots

65 Knots60 Knots

10° to 15°

Figure 8-7.To obtain necessary visual cues, the pilot should look toward the runway at a shallow angle.

Figure 8-6. Changing angle of attack during roundout.

Ch 08.qxd 5/7/04 8:08 AM Page 8-5

of visual interception with the runway to moveprogressively rearward toward the pilot as the airplaneloses altitude. This is an important visual cue inassessing the rate of altitude loss. Conversely, forwardmovement of the visual interception point will indicatean increase in altitude, and would mean that the pitchangle was increased too rapidly, resulting in an overflare. Location of the visual interception point inconjunction with assessment of flow velocity of nearbyoff-runway terrain, as well as the similarity ofappearance of height above the runway ahead of theairplane (in comparison to the way it looked when theairplane was taxied prior to takeoff) is also used tojudge when the wheels are just a few inches abovethe runway.

The pitch attitude of the airplane in a full-flap approachis considerably lower than in a no-flap approach. Toattain the proper landing attitude before touchingdown, the nose must travel through a greater pitchchange when flaps are fully extended. Since the round-out is usually started at approximately the same heightabove the ground regardless of the degree of flapsused, the pitch attitude must be increased at a fasterrate when full flaps are used; however, the roundoutshould still be executed at a rate proportionate to theairplane’s downward motion.

Once the actual process of rounding out is started, theelevator control should not be pushed forward. If toomuch back-elevator pressure has been exerted, thispressure should be either slightly relaxed or heldconstant, depending on the degree of the error. In somecases, it may be necessary to advance the throttleslightly to prevent an excessive rate of sink, or a stall, allof which would result in a hard, drop-in type landing.

It is recommended that the student pilot form the habitof keeping one hand on the throttle throughout theapproach and landing, should a sudden and unexpectedhazardous situation require an immediate applicationof power.

TOUCHDOWNThe touchdown is the gentle settling of the airplaneonto the landing surface. The roundout and touchdownshould be made with the engine idling, and the airplaneat minimum controllable airspeed, so that the airplanewill touch down on the main gear at approximatelystalling speed. As the airplane settles, the properlanding attitude is attained by application of whateverback-elevator pressure is necessary.

Some pilots may try to force or fly the airplane ontothe ground without establishing the proper landingattitude. The airplane should never be flown onthe runway with excessive speed. It is paradoxical thatthe way to make an ideal landing is to try to hold theairplane’s wheels a few inches off the ground aslong as possible with the elevators. In most cases,when the wheels are within 2 or 3 feet off theground, the airplane will still be settling too fast fora gentle touchdown; therefore, this descent must beretarded by further back-elevator pressure. Sincethe airplane is already close to its stalling speed andis settling, this added back-elevator pressure willonly slow up the settling instead of stopping it. Atthe same time, it will result in the airplane touchingthe ground in the proper landing attitude, and themain wheels touching down first so that little or noweight is on the nosewheel. [Figure 8-8]

After the main wheels make initial contact with theground, back-elevator pressure should be held tomaintain a positive angle of attack for aerodynamicbraking, and to hold the nosewheel off the ground untilthe airplane decelerates. As the airplane’s momentumdecreases, back-elevator pressure may be graduallyrelaxed to allow the nosewheel to gently settle onto therunway. This will permit steering with the nosewheel.At the same time, it will cause a low angle of attackand negative lift on the wings to prevent floating orskipping, and will allow the full weight of the airplaneto rest on the wheels for better braking action.

Near-Zero Rate of Descent

15 Feet

1 Foot2 to 3 Feet

Figure 8-8. A well executed roundout results in attaining the proper landing attitude.

8-6

Ch 08.qxd 5/7/04 8:08 AM Page 8-6

8-7

It is extremely important that the touchdown occurwith the airplane’s longitudinal axis exactly parallel tothe direction in which the airplane is moving along therunway. Failure to accomplish this imposes severe sideloads on the landing gear. To avoid these side stresses,the pilot should not allow the airplane to touch downwhile turned into the wind or drifting.

AFTER-LANDING ROLLThe landing process must never be considered com-plete until the airplane decelerates to the normal taxispeed during the landing roll or has been brought to acomplete stop when clear of the landing area. Manyaccidents have occurred as a result of pilots abandon-ing their vigilance and positive control after getting theairplane on the ground.

The pilot must be alert for directional control difficul-ties immediately upon and after touchdown due to theground friction on the wheels. The friction creates a pivotpoint on which a moment arm can act. Loss of directionalcontrol may lead to an aggravated, uncontrolled, tightturn on the ground, or a ground loop. The combinationof centrifugal force acting on the center of gravity (CG)and ground friction of the main wheels resisting it duringthe ground loop may cause the airplane to tip or leanenough for the outside wingtip to contact the ground.This may even impose a sideward force, which couldcollapse the landing gear.

The rudder serves the same purpose on the ground as itdoes in the air—it controls the yawing of the airplane.The effectiveness of the rudder is dependent on the air-flow, which depends on the speed of the airplane. Asthe speed decreases and the nosewheel has been low-ered to the ground, the steerable nose provides morepositive directional control.

The brakes of an airplane serve the same primarypurpose as the brakes of an automobile—to reducespeed on the ground. In airplanes, they may also beused as an aid in directional control when more pos-itive control is required than could be obtained withrudder or nosewheel steering alone.

To use brakes, on an airplane equipped with toe brakes,the pilot should slide the toes or feet up from the rud-der pedals to the brake pedals. If rudder pressure isbeing held at the time braking action is needed, thatpressure should not be released as the feet or toes arebeing slid up to the brake pedals, because control maybe lost before brakes can be applied.

Putting maximum weight on the wheels after touch-down is an important factor in obtaining optimumbraking performance. During the early part of rollout,some lift may continue to be generated by the wing.After touchdown, the nosewheel should be lowered to

the runway to maintain directional control. Duringdeceleration, the nose may be pitched down by brakingand the weight transferred to the nosewheel from themain wheels. This does not aid in braking action, soback pressure should be applied to the controls withoutlifting the nosewheel off the runway. This will enablethe pilot to maintain directional control while keepingweight on the main wheels.

Careful application of the brakes can be initiated afterthe nosewheel is on the ground and directional controlis established. Maximum brake effectiveness is justshort of the point where skidding occurs. If the brakesare applied so hard that skidding takes place, brakingbecomes ineffective. Skidding can be stopped by releas-ing the brake pressure. Also, braking effectiveness is notenhanced by alternately applying and reapplying brakepressure. The brakes should be applied firmly andsmoothly as necessary.

During the ground roll, the airplane’s direction ofmovement can be changed by carefully applying pres-sure on one brake or uneven pressures on each brake inthe desired direction. Caution must be exercised whenapplying brakes to avoid overcontrolling.

The ailerons serve the same purpose on the ground asthey do in the air—they change the lift and drag com-ponents of the wings. During the after-landing roll,they should be used to keep the wings level in muchthe same way they were used in flight. If a wing startsto rise, aileron control should be applied toward thatwing to lower it. The amount required will depend onspeed because as the forward speed of the airplanedecreases, the ailerons will become less effective.Procedures for using ailerons in crosswind conditionsare explained further in this chapter, in the CrosswindApproach and Landing section.

After the airplane is on the ground, back-elevator pres-sure may be gradually relaxed to place normal weight onthe nosewheel to aid in better steering. If availablerunway permits, the speed of the airplane should beallowed to dissipate in a normal manner. Once theairplane has slowed sufficiently and has turned on tothe taxiway and stopped, the pilot should retract theflaps and clean up the airplane. Many accidents haveoccurred as a result of the pilot unintentionally operatingthe landing gear control and retracting the gear insteadof the flap control when the airplane was stillrolling. The habit of positively identifying both of thesecontrols, before actuating them, should be formed fromthe very beginning of flight training and continued in allfuture flying activities.

STABILIZED APPROACH CONCEPTA stabilized approach is one in which the pilot estab-lishes and maintains a constant angle glidepath

Ch 08.qxd 5/7/04 8:08 AM Page 8-7

8-8

towards a predetermined point on the landing runway.It is based on the pilot’s judgment of certain visualclues, and depends on the maintenance of a constantfinal descent airspeed and configuration.

An airplane descending on final approach at a constantrate and airspeed will be traveling in a straight linetoward a spot on the ground ahead. This spot will notbe the spot on which the airplane will touch down,because some float will inevitably occur during theroundout (flare). [Figure 8-9] Neither will it be the spottoward which the airplane’s nose is pointed, becausethe airplane is flying at a fairly high angle of attack,and the component of lift exerted parallel to the Earth’ssurface by the wings tends to carry the airplane for-ward horizontally.

The point toward which the airplane is progressing istermed the “aiming point.” [Figure 8-9] It is the pointon the ground at which, if the airplane maintains aconstant glidepath, and was not flared for landing, itwould strike the ground. To a pilot moving straightahead toward an object, it appears to be stationary. Itdoes not “move.” This is how the aiming point can bedistinguished—it does not move. However, objects infront of and beyond the aiming point do appear to moveas the distance is closed, and they appear to move inopposite directions. During instruction in landings, oneof the most important skills a student pilot must acquireis how to use visual cues to accurately determine thetrue aiming point from any distance out on finalapproach. From this, the pilot will not only be able todetermine if the glidepath will result in an undershootor overshoot, but, taking into account float duringroundout, the pilot will be able to predict the touch-down point to within a very few feet.

For a constant angle glidepath, the distance betweenthe horizon and the aiming point will remain constant.If a final approach descent has been established but thedistance between the perceived aiming point and the

horizon appears to increase (aiming point movingdown away from the horizon), then the true aimingpoint, and subsequent touchdown point, is fartherdown the runway. If the distance between the per-ceived aiming point and the horizon decreases (aimingpoint moving up toward the horizon), the true aimingpoint is closer than perceived.

When the airplane is established on final approach, theshape of the runway image also presents clues as towhat must be done to maintain a stabilized approachto a safe landing.

A runway, obviously, is normally shaped in the formof an elongated rectangle. When viewed from theair during the approach, the phenomenon known as

perspective causes the runway to assume the shape ofa trapezoid with the far end looking narrower than theapproach end, and the edge lines converging ahead.If the airplane continues down the glidepath at aconstant angle (stabilized), the image the pilot seeswill still be trapezoidal but of proportionately largerdimensions. In other words, during a stabilizedapproach the runway shape does not change. [Figure8-10]

If the approach becomes shallower, however, therunway will appear to shorten and become wider.Conversely, if the approach is steepened, the run-way will appear to become longer and narrower.[Figure 8-11]

The objective of a stabilized approach is to select anappropriate touchdown point on the runway, andadjust the glidepath so that the true aiming point andthe desired touchdown point basically coincide.Immediately after rolling out on final approach, thepilot should adjust the pitch attitude and power so thatthe airplane is descending directly toward the aimingpoint at the appropriate airspeed. The airplane should

Distance Traveled in Flare

Touchdown

Aiming Point (Descent Angle Intersects Ground)

Figure 8-9. Stabilized approach.

Ch 08.qxd 5/7/04 8:08 AM Page 8-8

be in the landing configuration, and trimmed for“hands off” flight. With the approach set up in thismanner, the pilot will be free to devote full attentiontoward outside references. The pilot should not stare atany one place, but rather scan from one point toanother, such as from the aiming point to the horizon,to the trees and bushes along the runway, to an areawell short of the runway, and back to the aiming point.In this way, the pilot will be more apt to perceive adeviation from the desired glidepath, and whether ornot the airplane is proceeding directly toward theaiming point.

If the pilot perceives any indication that the aimingpoint on the runway is not where desired, an adjustmentmust be made to the glidepath. This in turn will movethe aiming point. For instance, if the pilot perceives thatthe aiming point is short of the desired touchdownpoint and will result in an undershoot, an increase inpitch attitude and engine power is warranted. A constantairspeed must be maintained. The pitch and powerchange, therefore, must be made smoothly andsimultaneously. This will result in a shallowing ofthe glidepath with the resultant aiming point movingtowards the desired touchdown point. Conversely,if the pilot perceives that the aiming point is fartherdown the runway than the desired touchdown pointand will result in an overshoot, the glidepath should besteepened by a simultaneous decrease in pitch attitudeand power. Once again, the airspeed must be held con-stant. It is essential that deviations from the desiredglidepath be detected early, so that only slight andinfrequent adjustments to glidepath are required.

3°Approach Angle4000' x 100' Runway1600' From Threshold

105' Altitude

Same Runway, Same Approach Angle800' From Threshold

52' Altitude

Same Runway, Same Approach Angle400' From Threshold

26' Altitude

Figure 8-10. Runway shape during stabilized approach.

Too High

Proper Descent Angle

Too Low

Figure 8-11. Change in runway shape if approach becomesnarrow or steep.

8-9

Ch 08.qxd 5/7/04 8:08 AM Page 8-9

8-10

The closer the airplane gets to the runway, the larger(and possibly more frequent) the required correctionsbecome, resulting in an unstabilized approach.

Common errors in the performance of normalapproaches and landings are:

• Inadequate wind drift correction on the base leg.

• Overshooting or undershooting the turn ontofinal approach resulting in too steep or too shal-low a turn onto final approach.

• Flat or skidding turns from base leg to finalapproach as a result of overshooting/inadequatewind drift correction.

• Poor coordination during turn from base to finalapproach.

• Failure to complete the landing checklist in atimely manner.

• Unstabilized approach.

• Failure to adequately compensate for flap exten-sion.

• Poor trim technique on final approach.

• Attempting to maintain altitude or reach the run-way using elevator alone.

• Focusing too close to the airplane resulting in atoo high roundout.

• Focusing too far from the airplane resulting in atoo low roundout.

• Touching down prior to attaining proper landingattitude.

• Failure to hold sufficient back-elevator pressureafter touchdown.

• Excessive braking after touchdown.

INTENTIONAL SLIPSA slip occurs when the bank angle of an airplane is toosteep for the existing rate of turn. Unintentional slipsare most often the result of uncoordinatedrudder/aileron application. Intentional slips, however,are used to dissipate altitude without increasing air-speed, and/or to adjust airplane ground track during acrosswind. Intentional slips are especially useful inforced landings, and in situations where obstacles mustbe cleared during approaches to confined areas. A slipcan also be used as an emergency means of rapidly

reducing airspeed in situations where wing flaps areinoperative or not installed.

A slip is a combination of forward movement andsideward (with respect to the longitudinal axis of theairplane) movement, the lateral axis being inclinedand the sideward movement being toward the lowend of this axis (low wing). An airplane in a slip is infact flying sideways. This results in a change in thedirection the relative wind strikes the airplane. Slipsare characterized by a marked increase in drag andcorresponding decrease in airplane climb, cruise, andglide performance. It is the increase in drag, how-ever, that makes it possible for an airplane in a slip todescend rapidly without an increase in airspeed.

Most airplanes exhibit the characteristic of positivestatic directional stability and, therefore, have a natu-ral tendency to compensate for slipping. An intentionalslip, therefore, requires deliberate cross-controllingailerons and rudder throughout the maneuver.

A “sideslip” is entered by lowering a wing and applyingjust enough opposite rudder to prevent a turn. In asideslip, the airplane’s longitudinal axis remains par-allel to the original flightpath, but the airplane nolonger flies straight ahead. Instead the horizontalcomponent of wing lift forces the airplane also tomove somewhat sideways toward the low wing.[Figure 8-12] The amount of slip, and therefore therate of sideward movement, is determined by the bankangle. The steeper the bank—the greater the degree ofslip. As bank angle is increased, however, additionalopposite rudder is required to prevent turning.

A “forward slip” is one in which the airplane’sdirection of motion continues the same as before theslip was begun. Assuming the airplane is originallyin straight flight, the wing on the side toward which

Direction of M

ovement

Relative W

ind

Sideslip

Figure 8-12. Sideslip.

Ch 08.qxd 5/7/04 8:08 AM Page 8-10

8-11

the slip is to be made should be lowered by use of theailerons. Simultaneously, the airplane’s nose must beyawed in the opposite direction by applying oppositerudder so that the airplane’s longitudinal axis is at anangle to its original flightpath. [Figure 8-13] Thedegree to which the nose is yawed in the oppositedirection from the bank should be such that theoriginal ground track is maintained. In a forward slip,the amount of slip, and therefore the sink rate, isdetermined by the bank angle. The steeper the bank—the steeper the descent.

In most light airplanes, the steepness of a slip islimited by the amount of rudder travel available. Inboth sideslips and forward slips, the point may bereached where full rudder is required to maintainheading even though the ailerons are capable of furthersteepening the bank angle. This is the practical sliplimit, because any additional bank would cause theairplane to turn even though full opposite rudder isbeing applied. If there is a need to descend morerapidly even though the practical slip limit has beenreached, lowering the nose will not only increase thesink rate but will also increase airspeed. The increasein airspeed increases rudder effectiveness permittinga steeper slip. Conversely, when the nose is raised,rudder effectiveness decreases and the bank angle mustbe reduced.

Discontinuing a slip is accomplished by leveling thewings and simultaneously releasing the rudderpressure while readjusting the pitch attitude to thenormal glide attitude. If the pressure on the rudder isreleased abruptly, the nose will swing too quickly intoline and the airplane will tend to acquire excess speed.

Because of the location of the pitot tube and staticvents, airspeed indicators in some airplanes may haveconsiderable error when the airplane is in a slip. Thepilot must be aware of this possibility and recognize a

properly performed slip by the attitude of the airplane,the sound of the airflow, and the feel of the flightcontrols. Unlike skids, however, if an airplane in a slipis made to stall, it displays very little of the yawingtendency that causes a skidding stall to develop into aspin. The airplane in a slip may do little more than tendto roll into a wings level attitude. In fact, in someairplanes stall characteristics may even be improved.

GO-AROUNDS (REJECTED LANDINGS)Whenever landing conditions are not satisfactory, ago-around is warranted. There are many factors thatcan contribute to unsatisfactory landing conditions.Situations such as air traffic control requirements,unexpected appearance of hazards on the runway,overtaking another airplane, wind shear,wake turbulence, mechanical failure and/or anunstabilized approach are all examples of reasons todiscontinue a landing approach and make anotherapproach under more favorable conditions. Theassumption that an aborted landing is invariably theconsequence of a poor approach, which in turn is dueto insufficient experience or skill, is a fallacy. Thego-around is not strictly an emergency procedure. Itis a normal maneuver that may at times be used in anemergency situation. Like any other normal maneuver,the go-around must be practiced and perfected. The flightinstructor should emphasize early on, and the studentpilot should be made to understand, that the go-aroundmaneuver is an alternative to any approachand/or landing.

Although the need to discontinue a landing may ariseat any point in the landing process, the most criticalgo-around will be one started when very close to theground. Therefore, the earlier a condition that warrants ago-around is recognized, the safer the go-around/rejectedlanding will be. The go-around maneuver is notinherently dangerous in itself. It becomes dangerousonly when delayed unduly or executed improperly.Delay in initiating the go-around normally stems fromtwo sources: (1) landing expectancy, or set—theanticipatory belief that conditions are not asthreatening as they are and that the approach willsurely be terminated with a safe landing, and (2)pride—the mistaken belief that the act of going aroundis an admission of failure—failure to execute theapproach properly. The improper execution of the go-around maneuver stems from a lack of familiarity withthe three cardinal principles of the procedure: power,attitude, and configuration.

POWERPower is the pilot’s first concern. The instant thepilot decides to go around, full or maximum allow-able takeoff power must be applied smoothly andwithout hesitation, and held until flying speed andcontrollability are restored. Applying only partialpower in a go-around is never appropriate. The pilot

Dire

ctio

n of

Mov

emen

t

Rel

ativ

e W

ind

Forward Slip

Figure 8-13. Forward slip.

Ch 08.qxd 5/7/04 8:08 AM Page 8-11

must be aware of the degree of inertia that must beovercome, before an airplane that is settling towardsthe ground can regain sufficient airspeed to becomefully controllable and capable of turning safely orclimbing. The application of power should be smoothas well as positive. Abrupt movements of the throttlein some airplanes will cause the engine to falter.Carburetor heat should be turned off for maximumpower.

ATTITUDEAttitude is always critical when close to the ground,and when power is added, a deliberate effort on the partof the pilot will be required to keep the nose frompitching up prematurely. The airplane executing a go-around must be maintained in an attitude that permits abuildup of airspeed well beyond the stall point beforeany effort is made to gain altitude, or to execute a turn.Raising the nose too early may produce a stall fromwhich the airplane could not be recovered if thego-around is performed at a low altitude.

A concern for quickly regaining altitude during a go-around produces a natural tendency to pull the nose up.The pilot executing a go-around must accept the factthat an airplane will not climb until it can fly, and itwill not fly below stall speed. In some circumstances,it may be desirable to lower the nose briefly to gainairspeed. As soon as the appropriate climb airspeed andpitch attitude are attained, the pilot should “roughtrim” the airplane to relieve any adverse control pres-sures. Later, more precise trim adjustments can bemade when flight conditions have stabilized.

CONFIGURATIONIn cleaning up the airplane during the go-around, thepilot should be concerned first with flaps and secondlywith the landing gear (if retractable). When the deci-sion is made to perform a go-around, takeoff powershould be applied immediately and the pitch attitudechanged so as to slow or stop the descent. After thedescent has been stopped, the landing flaps may be

partially retracted or placed in the takeoff position asrecommended by the manufacturer. Caution must beused, however, in retracting the flaps. Depending onthe airplane’s altitude and airspeed, it may be wise toretract the flaps intermittently in small increments toallow time for the airplane to accelerate progressivelyas they are being raised. A sudden and complete retrac-tion of the flaps could cause a loss of lift resulting inthe airplane settling into the ground. [Figure 8-14]

Unless otherwise specified in the AFM/POH, it is gen-erally recommended that the flaps be retracted (at leastpartially) before retracting the landing gear—for tworeasons. First, on most airplanes full flaps producemore drag than the landing gear; and second, in casethe airplane should inadvertently touch down as thego-around is initiated, it is most desirable to have thelanding gear in the down-and-locked position. After apositive rate of climb is established, the landing gearcan be retracted.

When takeoff power is applied, it will usually be nec-essary to hold considerable pressure on the controls tomaintain straight flight and a safe climb attitude. Sincethe airplane has been trimmed for the approach (a lowpower and low airspeed condition), application ofmaximum allowable power will require considerablecontrol pressure to maintain a climb pitch attitude. Theaddition of power will tend to raise the airplane’s nosesuddenly and veer to the left. Forward elevator pressuremust be anticipated and applied to hold the nose in asafe climb attitude. Right rudder pressure must beincreased to counteract torque and P-factor, and to keepthe nose straight. The airplane must be held in the properflight attitude regardless of the amount of controlpressure that is required. Trim should be used torelieve adverse control pressures and assist the pilot inmaintaining a proper pitch attitude. On airplanes thatproduce high control pressures when using maximumpower on go-arounds, pilots should use caution whenreaching for the flap handle. Airplane control maybecome critical during this high workload phase.

Retract RemainingFlapsPositive Rate

of Climb, RetractGear, Climb

at VY

500'Cruise Climb

Timely Decision toMake Go-Around Apply Max Power

Adjust Pitch AttitudeAllow Airspeed to Increase

Assume Climb AtttudeFlaps to

Intermediate

Figure 8-14. Go-around procedure.

8-12

Ch 08.qxd 5/7/04 8:08 AM Page 8-12

8-13

The landing gear should be retracted only after the ini-tial or rough trim has been accomplished and when it iscertain the airplane will remain airborne. During theinitial part of an extremely low go-around, the airplanemay settle onto the runway and bounce. This situationis not particularly dangerous if the airplane is keptstraight and a constant, safe pitch attitude is main-tained. The airplane will be approaching safe flyingspeed rapidly and the advanced power will cushion anysecondary touchdown.

If the pitch attitude is increased excessively in an effortto keep the airplane from contacting the runway, it maycause the airplane to stall. This would be especiallylikely if no trim correction is made and the flapsremain fully extended. The pilot should not attempt toretract the landing gear until after a rough trim isaccomplished and a positive rate of climb is estab-lished.

GROUND EFFECTGround effect is a factor in every landing and everytakeoff in fixed-wing airplanes. Ground effect can alsobe an important factor in go-arounds. If the go-aroundis made close to the ground, the airplane may be in theground effect area. Pilots are often lulled into a senseof false security by the apparent “cushion of air” underthe wings that initially assists in the transition from anapproach descent to a climb. This “cushion of air,”however, is imaginary. The apparent increase in air-plane performance is, in fact, due to a reduction ininduced drag in the ground effect area. It is “borrowed”performance that must be repaid when the airplaneclimbs out of the ground effect area. The pilot mustfactor in ground effect when initiating a go-aroundclose to the ground. An attempt to climb prematurelymay result in the airplane not being able to climb, oreven maintain altitude at full power.

Common errors in the performance of go-arounds(rejected landings) are:

• Failure to recognize a condition that warrants arejected landing.

• Indecision.

• Delay in initiating a go-round.

• Failure to apply maximum allowable power in atimely manner.

• Abrupt power application.

• Improper pitch attitude.

• Failure to configure the airplane appropriately.

• Attempting to climb out of ground effect prema-turely.

• Failure to adequately compensate for torque/P-factor.

CROSSWIND APPROACH AND LANDINGMany runways or landing areas are such that landingsmust be made while the wind is blowing across ratherthan parallel to the landing direction. All pilots shouldbe prepared to cope with these situations when theyarise. The same basic principles and factors involvedin a normal approach and landing apply to a crosswindapproach and landing; therefore, only the additionalprocedures required for correcting for wind drift arediscussed here.

Crosswind landings are a little more difficult to per-form than crosswind takeoffs, mainly due to differentproblems involved in maintaining accurate control ofthe airplane while its speed is decreasing rather thanincreasing as on takeoff.

There are two usual methods of accomplishing a cross-wind approach and landing—the crab method and thewing-low (sideslip) method. Although the crab methodmay be easier for the pilot to maintain during finalapproach, it requires a high degree of judgment andtiming in removing the crab immediately prior totouchdown. The wing-low method is recommended inmost cases, although a combination of both methodsmay be used.

CROSSWIND FINAL APPROACHThe crab method is executed by establishing a heading(crab) toward the wind with the wings level so that theairplane’s ground track remains aligned with the cen-terline of the runway. [Figure 8-15] This crab angle ismaintained until just prior to touchdown, when thelongitudinal axis of the airplane must be aligned withthe runway to avoid sideward contact of the wheelswith the runway. If a long final approach is beingflown, the pilot may use the crab method until justbefore the roundout is started and then smoothlychange to the wing-low method for the remainder ofthe landing.

Figure 8-15. Crabbed approach.

The wing-low (sideslip) method will compensate for acrosswind from any angle, but more important, it

Ch 08.qxd 5/7/04 8:08 AM Page 8-13

enables the pilot to simultaneously keep the airplane’sground track and longitudinal axis aligned with therunway centerline throughout the final approach,roundout, touchdown, and after-landing roll. Thisprevents the airplane from touching down in a side-ward motion and imposing damaging side loads onthe landing gear.

To use the wing-low method, the pilot aligns the air-plane’s heading with the centerline of the runway,notes the rate and direction of drift, and then promptlyapplies drift correction by lowering the upwind wing.[Figure 8-16] The amount the wing must be lowereddepends on the rate of drift. When the wing is lowered,

the airplane will tend to turn in that direction. It is thennecessary to simultaneously apply sufficient oppositerudder pressure to prevent the turn and keep the air-plane’s longitudinal axis aligned with the runway. Inother words, the drift is controlled with aileron, andthe heading with rudder. The airplane will now besideslipping into the wind just enough that both theresultant flightpath and the ground track are alignedwith the runway. If the crosswind diminishes, thiscrosswind correction is reduced accordingly, or theairplane will begin slipping away from the desiredapproach path. [Figure 8-17]

To correct for strong crosswind, the slip into the windis increased by lowering the upwind wing a consider-able amount. As a consequence, this will result in agreater tendency of the airplane to turn. Since turningis not desired, considerable opposite rudder must beapplied to keep the airplane’s longitudinal axis alignedwith the runway. In some airplanes, there may not besufficient rudder travel available to compensate for thestrong turning tendency caused by the steep bank. Ifthe required bank is such that full opposite rudder willnot prevent a turn, the wind is too strong to safely landthe airplane on that particular runway with those windconditions. Since the airplane’s capability will beexceeded, it is imperative that the landing be made on

Figure 8-16. Sideslip approach.

Figure 8-17. Crosswind approach and landing.

8-14

Ch 08.qxd 5/7/04 8:08 AM Page 8-14

8-15

a more favorable runway either at that airport or at analternate airport.

Flaps can and should be used during most approachessince they tend to have a stabilizing effect on the air-plane. The degree to which flaps should be extendedwill vary with the airplane’s handling characteristics,as well as the wind velocity.

CROSSWIND ROUNDOUT (FLARE)Generally, the roundout can be made like a normallanding approach, but the application of a crosswindcorrection is continued as necessary to preventdrifting.

Since the airspeed decreases as the roundout pro-gresses, the flight controls gradually become lesseffective. As a result, the crosswind correction beingheld will become inadequate. When using the wing-low method, it is necessary to gradually increase thedeflection of the rudder and ailerons to maintain theproper amount of drift correction.

Do not level the wings; keep the upwind wing downthroughout the roundout. If the wings are leveled, theairplane will begin drifting and the touchdown willoccur while drifting. Remember, the primary objectiveis to land the airplane without subjecting it to any sideloads that result from touching down while drifting.

CROSSWIND TOUCHDOWNIf the crab method of drift correction has been usedthroughout the final approach and roundout, the crabmust be removed the instant before touchdown byapplying rudder to align the airplane’s longitudinalaxis with its direction of movement. This requirestimely and accurate action. Failure to accomplish thiswill result in severe side loads being imposed on thelanding gear.

If the wing-low method is used, the crosswind correc-tion (aileron into the wind and opposite rudder)should be maintained throughout the roundout, andthe touchdown made on the upwind main wheel.

During gusty or high wind conditions, prompt adjust-ments must be made in the crosswind correction toassure that the airplane does not drift as the airplanetouches down.

As the forward momentum decreases after initialcontact, the weight of the airplane will cause thedownwind main wheel to gradually settle onto therunway.

In those airplanes having nosewheel steering intercon-nected with the rudder, the nosewheel may not bealigned with the runway as the wheels touch down

because opposite rudder is being held in the crosswindcorrection. To prevent swerving in the direction thenosewheel is offset, the corrective rudder pressuremust be promptly relaxed just as the nosewheeltouches down.

CROSSWIND AFTER-LANDING ROLLParticularly during the after-landing roll, specialattention must be given to maintaining directionalcontrol by the use of rudder or nosewheel steering,while keeping the upwind wing from rising by the useof aileron.

When an airplane is airborne, it moves with the airmass in which it is flying regardless of the airplane’sheading and speed. When an airplane is on the ground,it is unable to move with the air mass (crosswind)because of the resistance created by ground friction onthe wheels.

Characteristically, an airplane has a greater profile orside area, behind the main landing gear than forwardof it does. With the main wheels acting as a pivot pointand the greater surface area exposed to the crosswindbehind that pivot point, the airplane will tend to turn orweathervane into the wind.

Wind acting on an airplane during crosswind landingsis the result of two factors. One is the natural wind,which acts in the direction the air mass is traveling, whilethe other is induced by the movement of the airplane andacts parallel to the direction of movement. Consequently,a crosswind has a headwind component acting alongthe airplane’s ground track and a crosswind componentacting 90° to its track. The resultant or relative wind issomewhere between the two components. As theairplane’s forward speed decreases during the after-landing roll, the headwind component decreases and therelative wind has more of a crosswind component. Thegreater the crosswind component, the more difficult it isto prevent weathervaning.

Retaining control on the ground is a critical part of theafter-landing roll, because of the weathervaning effectof the wind on the airplane. Additionally, tire side loadfrom runway contact while drifting frequently gener-ates roll-overs in tricycle geared airplanes. The basicfactors involved are cornering angle and side load.

Cornering angle is the angular difference between theheading of a tire and its path. Whenever a load bearingtire’s path and heading diverge, a side load is created.It is accompanied by tire distortion. Although side loaddiffers in varying tires and air pressures, it is completelyindependent of speed, and through a considerablerange, is directional proportional to the cornering angleand the weight supported by the tire. As little as 10° ofcornering angle will create a side load equal to half the

Ch 08.qxd 5/7/04 8:08 AM Page 8-15

supported weight; after 20° the side load does notincrease with increasing cornering angle. For eachhigh-wing, tricycle geared airplane, there is a corner-ing angle at which roll-over is inevitable. The roll-overaxis being the line linking the nose and main wheels.At lesser angles, the roll-over may be avoided by useof ailerons, rudder, or steerable nosewheel but notbrakes.

While the airplane is decelerating during the after-landing roll, more and more aileron is applied to keepthe upwind wing from rising. Since the airplane isslowing down, there is less airflow around the aileronsand they become less effective. At the same time, therelative wind is becoming more of a crosswind andexerting a greater lifting force on the upwind wing.When the airplane is coming to a stop, the aileron con-trol must be held fully toward the wind.

MAXIMUM SAFE CROSSWIND VELOCITIESTakeoffs and landings in certain crosswind conditionsare inadvisable or even dangerous. [Figure 8-18] If thecrosswind is great enough to warrant an extreme driftcorrection, a hazardous landing condition may result.Therefore, the takeoff and landing capabilities withrespect to the reported surface wind conditions and theavailable landing directions must be considered.

Figure 8-18. Crosswind chart.

Before an airplane is type certificated by the FederalAviation Administration (FAA), it must be flight testedto meet certain requirements. Among these is thedemonstration of being satisfactorily controllable withno exceptional degree of skill or alertness on the partof the pilot in 90° crosswinds up to a velocity equal to0.2 VSO. This means a windspeed of two-tenths of theairplane’s stalling speed with power off and landinggear/flaps down. Regulations require that the demon-strated crosswind velocity be included on a placard inairplanes certificated after May 3, 1962.

The headwind component and the crosswind componentfor a given situation can be determined by referenceto a crosswind component chart. [Figure 8-19] It isimperative that pilots determine the maximumcrosswind component of each airplane they fly, andavoid operations in wind conditions that exceed thecapability of the airplane.

Figure 8-19. Crosswind component chart.

Common errors in the performance of crosswindapproaches and landings are:

• Attempting to land in crosswinds that exceed theairplane’s maximum demonstrated crosswindcomponent.

• Inadequate compensation for wind drift on theturn from base leg to final approach, resulting inundershooting or overshooting.

• Inadequate compensation for wind drift on finalapproach.

• Unstabilized approach.

• Failure to compensate for increased drag duringsideslip resulting in excessive sink rate and/ortoo low an airspeed.

• Touchdown while drifting.

60

50

40

30

20

10

0

Win

d V

eloc

ity –

MP

H

20 40 60 80 100Wind Angle – Degrees

DirectCrosswind

8-16

60

50

40

30

20

10

0

Hea

dwin

d C

ompo

nent

10 20 30 40 50 60Crosswind Component

10°0°20°

30°40°

50°

60°

70°

80°

90°

WINDVELO

CITY

Ch 08.qxd 5/7/04 8:08 AM Page 8-16

• Excessive airspeed on touchdown.

• Failure to apply appropriate flight control inputsduring rollout.

• Failure to maintain direction control on rollout.

• Excessive braking.

TURBULENT AIR APPROACH AND LANDINGPower-on approaches at an airspeed slightly above thenormal approach speed should be used for landing inturbulent air. This provides for more positive controlof the airplane when strong horizontal wind gusts, orup and down drafts, are experienced. Like otherpower-on approaches (when the pilot can vary theamount of power), a coordinated combination of bothpitch and power adjustments is usually required. As inmost other landing approaches, the proper approachattitude and airspeed require a minimum roundout andshould result in little or no floating during the landing.

To maintain good control, the approach in turbulent airwith gusty crosswind may require the use of partialwing flaps. With less than full flaps, the airplane willbe in a higher pitch attitude. Thus, it will require lessof a pitch change to establish the landing attitude, andthe touchdown will be at a higher airspeed to ensuremore positive control. The speed should not be soexcessive that the airplane will float past the desiredlanding area.

One procedure is to use the normal approach speedplus one-half of the wind gust factors. If the normalspeed is 70 knots, and the wind gusts increase 15 knots,airspeed of 77 knots is appropriate. In any case, the air-speed and the amount of flaps should be as the airplanemanufacturer recommends.

An adequate amount of power should be used to main-tain the proper airspeed and descent path throughoutthe approach, and the throttle retarded to idling positiononly after the main wheels contact the landing surface.Care must be exercised in closing the throttle before thepilot is ready for touchdown. In this situation, the suddenor premature closing of the throttle may cause a suddenincrease in the descent rate that could result in a hardlanding.

Landings from power approaches in turbulence shouldbe such that the touchdown is made with the airplanein approximately level flight attitude. The pitch attitudeat touchdown should be only enough to prevent thenosewheel from contacting the surface before the mainwheels have touched the surface. After touchdown, thepilot should avoid the tendency to apply forward pres-sure on the yoke as this may result in wheelbarrowingand possible loss of control. The airplane should beallowed to decelerate normally, assisted by careful useof wheel brakes. Heavy braking should be avoided untilthe wings are devoid of lift and the airplane’s fullweight is resting on the landing gear.

SHORT-FIELD APPROACH AND LANDINGShort-field approaches and landings require the use ofprocedures for approaches and landings at fields with arelatively short landing area or where an approach ismade over obstacles that limit the available landing area.[Figures 8-20 and 8-21] As in short-field takeoffs, it isone of the most critical of the maximum performanceoperations. It requires that the pilot fly the airplane atone of its crucial performance capabilities while close tothe ground in order to safely land within confined areas.This low-speed type of power-on approach is closelyrelated to the performance of flight at minimumcontrollable airspeeds.

8-17

Effective RunwayLength

Obstacle Clearance

Figure 8-20. Landing over an obstacle.

Ch 08.qxd 5/7/04 8:08 AM Page 8-17

To land within a short-field or a confined area, the pilotmust have precise, positive control of the rate ofdescent and airspeed to produce an approach that willclear any obstacles, result in little or no floating duringthe roundout, and permit the airplane to be stopped inthe shortest possible distance.

The procedures for landing in a short-field or for land-ing approaches over obstacles, as recommended in theAFM/POH, should be used. A stabilized approach isessential. [Figures 8-22 and 8-23] These proceduresgenerally involve the use of full flaps, and the finalapproach started from an altitude of at least 500 feethigher than the touchdown area. A wider than normalpattern should be used so that the airplane can beproperly configured and trimmed. In the absence ofthe manufacturer’s recommended approach speed, aspeed of not more than 1.3 VSO should be used. Forexample, in an airplane that stalls at 60 knots withpower off, and flaps and landing gear extended, theapproach speed should not be higher than 78 knots. Ingusty air, no more than one-half the gust factor shouldbe added. An excessive amount of airspeed could resultin a touchdown too far from the runway threshold oran after-landing roll that exceeds the available landingarea.

After the landing gear and full flaps have beenextended, the pilot should simultaneously adjust thepower and the pitch attitude to establish and maintainthe proper descent angle and airspeed. A coordinatedcombination of both pitch and power adjustments isrequired. When this is done properly, very little changein the airplane’s pitch attitude and power setting isnecessary to make corrections in the angle of descentand airspeed.

The short-field approach and landing is in reality anaccuracy approach to a spot landing. The procedurespreviously outlined in the section on the stabilizedapproach concept should be used. If it appears thatthe obstacle clearance is excessive and touchdownwill occur well beyond the desired spot, leavinginsufficient room to stop, power may be reducedwhile lowering the pitch attitude to steepen thedescent path and increase the rate of descent. If itappears that the descent angle will not ensure safeclearance of obstacles, power should be increasedwhile simultaneously raising the pitch attitude toshallow the descent path and decrease the rate ofdescent. Care must be taken to avoid an excessivelylow airspeed. If the speed is allowed to become tooslow, an increase in pitch and application of full power

Effective Runway LengthNon-Obstacle Clearance

Figure 8-21. Landing on a short-field.

Figure 8-22. Stabilized approach.

8-18

Stabilized

Ch 08.qxd 5/7/04 8:08 AM Page 8-18

may only result in a further rate of descent. This occurswhen the angle of attack is so great and creating somuch drag that the maximum available power isinsufficient to overcome it. This is generally referredto as operating in the region of reversed commandor operating on the back side of the power curve.

Because the final approach over obstacles is made at arelatively steep approach angle and close to the air-plane’s stalling speed, the initiation of the roundout orflare must be judged accurately to avoid flying into theground, or stalling prematurely and sinking rapidly. Alack of floating during the flare, with sufficient controlto touch down properly, is one verification that theapproach speed was correct.

Touchdown should occur at the minimum controllableairspeed with the airplane in approximately the pitchattitude that will result in a power-off stall when thethrottle is closed. Care must be exercised to avoid clos-ing the throttle too rapidly before the pilot is ready fortouchdown, as closing the throttle may result in animmediate increase in the rate of descent and a hardlanding.

Upon touchdown, the airplane should be held in thispositive pitch attitude as long as the elevators remaineffective. This will provide aerodynamic braking toassist in deceleration.

Immediately upon touchdown, and closing the throttle,appropriate braking should be applied to minimize theafter-landing roll. The airplane should be stoppedwithin the shortest possible distance consistent withsafety and controllability. If the proper approach speedhas been maintained, resulting in minimum floatduring the roundout, and the touchdown made atminimum control speed, minimum braking will berequired.

Common errors in the performance of short-fieldapproaches and landings are:

• Failure to allow enough room on final to set upthe approach, necessitating an overly steepapproach and high sink rate.

• Unstabilized approach.

• Undue delay in initiating glidepath corrections.

• Too low an airspeed on final resulting in inabilityto flare properly and landing hard.

• Too high an airspeed resulting in floating onroundout.

• Prematurely reducing power to idle on roundoutresulting in hard landing.

• Touchdown with excessive airspeed.

• Excessive and/or unnecessary braking aftertouchdown.

• Failure to maintain directional control.

SOFT-FIELD APPROACH AND LANDINGLanding on fields that are rough or have soft surfaces,such as snow, sand, mud, or tall grass requires uniqueprocedures. When landing on such surfaces, theobjective is to touch down as smoothly as possible,and at the slowest possible landing speed. The pilotmust control the airplane in a manner that the wingssupport the weight of the airplane as long as practi-cal, to minimize drag and stresses imposed on thelanding gear by the rough or soft surface.

The approach for the soft-field landing is similar to thenormal approach used for operating into long, firmlanding areas. The major difference between the two is

Figure 8-23. Unstabilized approach.

Unstabilized

8-19

Ch 08.qxd 5/7/04 8:08 AM Page 8-19

that, during the soft-field landing, the airplane is held1 to 2 feet off the surface in ground effect as long aspossible. This permits a more gradual dissipation offorward speed to allow the wheels to touch down gen-tly at minimum speed. This technique minimizes thenose-over forces that suddenly affect the airplane atthe moment of touchdown. Power can be usedthroughout the level-off and touchdown to ensuretouchdown at the slowest possible airspeed, and theairplane should be flown onto the ground with theweight fully supported by the wings. [Figure 8-24]

The use of flaps during soft-field landings will aid intouching down at minimum speed and is recommendedwhenever practical. In low-wing airplanes, the flapsmay suffer damage from mud, stones, or slush thrownup by the wheels. If flaps are used, it is generally inad-visable to retract them during the after-landing rollbecause the need for flap retraction is usually lessimportant than the need for total concentration onmaintaining full control of the airplane.

The final approach airspeed used for short-field land-ings is equally appropriate to soft-field landings. Theuse of higher approach speeds may result in excessivefloat in ground effect, and floating makes a smooth,controlled touchdown even more difficult. There is,however, no reason for a steep angle of descent unlessobstacles are present in the approach path.

Touchdown on a soft or rough field should be made atthe lowest possible airspeed with the airplane in anose-high pitch attitude. In nosewheel-type airplanes,after the main wheels touch the surface, the pilotshould hold sufficient back-elevator pressure to keepthe nosewheel off the surface. Using back-elevatorpressure and engine power, the pilot can control therate at which the weight of the airplane is transferredfrom the wings to the wheels.

Field conditions may warrant that the pilot maintain aflight condition in which the main wheels are just

touching the surface but the weight of the airplane isstill being supported by the wings, until a suitable taxisurface is reached. At any time during this transitionphase, before the weight of the airplane is being sup-ported by the wheels, and before the nosewheel is onthe surface, the pilot should be able to apply fullpower and perform a safe takeoff (obstacle clearanceand field length permitting) should the pilot elect toabandon the landing. Once committed to a landing,the pilot should gently lower the nosewheel to thesurface. A slight addition of power usually will aid ineasing the nosewheel down.

The use of brakes on a soft field is not needed andshould be avoided as this may tend to impose a heavyload on the nose gear due to premature or hard contactwith the landing surface, causing the nosewheel to digin. The soft or rough surface itself will provide suffi-cient reduction in the airplane’s forward speed. Often itwill be found that upon landing on a very soft field, thepilot will need to increase power to keep the airplanemoving and from becoming stuck in the soft surface.

Common errors in the performance of soft-fieldapproaches and landings are:

• Excessive descent rate on final approach.

• Excessive airspeed on final approach.

• Unstabilized approach.

• Roundout too high above the runway surface.

• Poor power management during roundout andtouchdown.

• Hard touchdown.

• Inadequate control of the airplane weight trans-fer from wings to wheels after touchdown.

• Allowing the nosewheel to “fall” to the runwayafter touchdown rather than controlling itsdescent.

Figure 8-24. Soft/rough field approach and landing.

8-20

Ground Effect

TransitionArea

Ch 08.qxd 5/7/04 8:08 AM Page 8-20

8-21

POWER-OFF ACCURACYAPPROACHESPower-off accuracy approaches are approaches andlandings made by gliding with the engine idling,through a specific pattern to a touchdown beyond andwithin 200 feet of a designated line or mark on the run-way. The objective is to instill in the pilot the judgmentand procedures necessary for accurately flying the air-plane, without power, to a safe landing.

The ability to estimate the distance an airplane will glideto a landing is the real basis of all power-off accuracyapproaches and landings. This will largely determine theamount of maneuvering that may be done from a givenaltitude. In addition to the ability to estimate distance, itrequires the ability to maintain the proper glide whilemaneuvering the airplane.

With experience and practice, altitudes up to approxi-mately 1,000 feet can be estimated with fair accuracy,while above this level the accuracy in judgment of heightabove the ground decreases, since all features tend tomerge. The best aid in perfecting the ability to judgeheight above this altitude is through the indications of thealtimeter and associating them with the generalappearance of the Earth.

The judgment of altitude in feet, hundreds of feet, orthousands of feet is not as important as the ability toestimate gliding angle and its resultant distance. Thepilot who knows the normal glide angle of the airplanecan estimate with reasonable accuracy, the approximatespot along a given ground path at which the airplanewill land, regardless of altitude. The pilot, who also hasthe ability to accurately estimate altitude, can judgehow much maneuvering is possible during the glide,which is important to the choice of landing areas in anactual emergency.

The objective of a good final approach is to descend atan angle that will permit the airplane to reach thedesired landing area, and at an airspeed that will resultin minimum floating just before touchdown. Toaccomplish this, it is essential that both the descentangle and the airspeed be accurately controlled.

Unlike a normal approach when the power setting isvariable, on a power-off approach the power is fixed atthe idle setting. Pitch attitude is adjusted to control theairspeed. This will also change the glide or descentangle. By lowering the nose to keep the approach airspeedconstant, the descent angle will steepen. If the airspeed istoo high, raise the nose, and when the airspeed is too low,lower the nose. If the pitch attitude is raised too high, theairplane will settle rapidly due to a slow airspeed andinsufficient lift. For this reason, never try to stretch a glideto reach the desired landing spot.

Uniform approach patterns such as the 90°, 180°, or360° power-off approaches are described further in thischapter. Practice in these approaches provides the pilotwith a basis on which to develop judgment in glidingdistance and in planning an approach.

The basic procedure in these approaches involves clos-ing the throttle at a given altitude, and gliding to a keyposition. This position, like the pattern itself, must notbe allowed to become the primary objective; it ismerely a convenient point in the air from which thepilot can judge whether the glide will safely terminateat the desired spot. The selected key position should beone that is appropriate for the available altitude and thewind condition. From the key position, the pilot mustconstantly evaluate the situation.

It must be emphasized that, although accurate spottouchdowns are important, safe and properly executedapproaches and landings are vital. The pilot must neversacrifice a good approach or landing just to land on thedesired spot.

90° POWER-OFF APPROACHThe 90° power-off approach is made from a base leg andrequires only a 90° turn onto the final approach. Theapproach path may be varied by positioning the base legcloser to or farther out from the approach end of the run-way according to wind conditions. [Figure 8-25]

The glide from the key position on the base leg throughthe 90° turn to the final approach is the final part of allaccuracy landing maneuvers.

The 90° power-off approach usually begins from arectangular pattern at approximately 1,000 feet abovethe ground or at normal traffic pattern altitude. Theairplane should be flown onto a downwind leg at thesame distance from the landing surface as in a normaltraffic pattern. The before landing checklist should becompleted on the downwind leg, including extensionof the landing gear if the airplane is equipped withretractable gear.

After a medium-banked turn onto the base leg is com-pleted, the throttle should be retarded slightly and theairspeed allowed to decrease to the normal base-legspeed. [Figure 8-26] On the base leg, the airspeed,wind drift correction, and altitude should be maintainedwhile proceeding to the 45° key position. At thisposition, the intended landing spot will appear to beon a 45° angle from the airplane’s nose.

The pilot can determine the strength and direction ofthe wind from the amount of crab necessary to hold thedesired ground track on the base leg. This will help inplanning the turn onto the final approach and in lower-ing the correct amount of flaps.

Ch 08.qxd 5/7/04 8:08 AM Page 8-21

At the 45° key position, the throttle should be closedcompletely, the propeller control (if equipped)advanced to the full increase r.p.m. position, and alti-tude maintained until the airspeed decreases to themanufacturer’s recommended glide speed. In theabsence of a recommended speed, use 1.4 VSO. Whenthis airspeed is attained, the nose should be lowered tomaintain the gliding speed and the controls retrimmed.

The base-to-final turn should be planned and accom-plished so that upon rolling out of the turn the airplanewill be aligned with the runway centerline. When onfinal approach, the wing flaps are lowered and thepitch attitude adjusted, as necessary, to establish theproper descent angle and airspeed (1.3 VSO), then thecontrols retrimmed. Slight adjustments in pitch attitudeor flaps setting may be necessary to control the glide

Light Wind

Medium Wind

Strong Wind

Figure 8-25. Plan the base leg for wind conditions.

Figure 8-26. 90° power-off approach.

8-22

45°

Power ReducedBase Leg Speed

Close ThrottleEstablished 1.4 V

Base KeyPosition

Lower Partial FlapsMaintain 1.4 V

Lower Full Flaps(As Needed)

Establish 1.3 V

S0

S0

S0

Ch 08.qxd 5/7/04 8:08 AM Page 8-22

8-23

angle and airspeed. However, NEVER TRY TOSTRETCH THE GLIDE OR RETRACT THE FLAPSto reach the desired landing spot. The final approachmay be made with or without the use of slips.

After the final approach glide has been established, fullattention is then given to making a good, safe landingrather than concentrating on the selected landing spot.The base-leg position and the flap setting alreadydetermined the probability of landing on the spot. Inany event, it is better to execute a good landing 200feet from the spot than to make a poor landing pre-cisely on the spot.

180° POWER-OFF APPROACHThe 180° power-off approach is executed by glidingwith the power off from a given point on a downwindleg to a preselected landing spot. [Figure 8-27] It is anextension of the principles involved in the 90° power-off approach just described. Its objective is to furtherdevelop judgment in estimating distances and glideratios, in that the airplane is flown without power froma higher altitude and through a 90° turn to reach thebase-leg position at a proper altitude for executing the90° approach.

The 180° power-off approach requires more planningand judgment than the 90° power-off approach. In theexecution of 180° power-off approaches, the airplaneis flown on a downwind heading parallel to the landingrunway. The altitude from which this type of approachshould be started will vary with the type of airplane,

but it should usually not exceed 1,000 feet above theground, except with large airplanes. Greater accuracyin judgment and maneuvering is required at higheraltitudes.

When abreast of or opposite the desired landing spot,the throttle should be closed and altitude maintainedwhile decelerating to the manufacturer’s recommendedglide speed, or 1.4 VSO. The point at which the throttleis closed is the downwind key position.

The turn from the downwind leg to the base leg shouldbe a uniform turn with a medium or slightly steeperbank. The degree of bank and amount of this initialturn will depend upon the glide angle of the airplaneand the velocity of the wind. Again, the base leg shouldbe positioned as needed for the altitude, or wind con-dition. Position the base leg to conserve or dissipatealtitude so as to reach the desired landing spot.

The turn onto the base leg should be made at an alti-tude high enough and close enough to permit theairplane to glide to what would normally be thebase key position in a 90° power-off approach.

Although the key position is important, it must not beoveremphasized nor considered as a fixed point onthe ground. Many inexperienced pilots may gain aconception of it as a particular landmark, such as atree, crossroad, or other visual reference, to bereached at a certain altitude. This will result in amechanical conception and leave the pilot at a total

Figure 8-27. 180° power-off approach.

Medium orSteeper Bank

Lower Partial FlapsMaintain 1.4 Vs0

Lower Full Flaps(as Needed)

Establish 1.3 Vs0

Key Position

Close ThrottleNormal Glide Speed

90°

Downwind LegKey Position

Ch 08.qxd 5/7/04 8:08 AM Page 8-23

8-24

loss any time such objects are not present. Both alti-tude and geographical location should be varied asmuch as is practical to eliminate any such conception.After reaching the base key position, the approach andlanding are the same as in the 90° power-off approach.

360° POWER-OFF APPROACHThe 360° power-off approach is one in which the air-plane glides through a 360° change of direction tothe preselected landing spot. The entire pattern isdesigned to be circular, but the turn may be shallowed,steepened, or discontinued at any point to adjust theaccuracy of the flightpath.

The 360° approach is started from a position over theapproach end of the landing runway or slightly to theside of it, with the airplane headed in the proposedlanding direction and the landing gear and flapsretracted. [Figure 8-28]

It is usually initiated from approximately 2,000 feet ormore above the ground—where the wind may vary sig-nificantly from that at lower altitudes. This must betaken into account when maneuvering the airplane to apoint from which a 90° or 180° power-off approachcan be completed.

After the throttle is closed over the intended point oflanding, the proper glide speed should immediately beestablished, and a medium-banked turn made in thedesired direction so as to arrive at the downwind keyposition opposite the intended landing spot. At or just

beyond the downwind key position, the landing gearmay be extended if the airplane is equipped withretractable gear. The altitude at the downwind keyposition should be approximately 1,000 to 1,200 feetabove the ground.

After reaching that point, the turn should be continuedto arrive at a base-leg key position, at an altitude ofabout 800 feet above the terrain. Flaps may be used atthis position, as necessary, but full flaps should not beused until established on the final approach.

The angle of bank can be varied as needed throughoutthe pattern to correct for wind conditions and to alignthe airplane with the final approach. The turn-to-finalshould be completed at a minimum altitude of 300 feetabove the terrain.

Common errors in the performance of power-off accu-racy approaches are:

• Downwind leg too far from the runway/landingarea.

• Overextension of downwind leg resulting fromtailwind.

• Inadequate compensation for wind drift on baseleg.

• Skidding turns in an effort to increase glidingdistance.

Figure 8-28. 360° power-off approach.

Normal Glide Speed

Normal GlideSpeed

Lower Partial FlapsMaintain 1.4 Vs0

Lower Flapsas Needed

Establish 1.3 Vs0

Key Position

Key Position

Close Throttle, Retract Flaps

Ch 08.qxd 5/7/04 8:08 AM Page 8-24

• Failure to lower landing gear in retractable gearairplanes.

• Attempting to “stretch” the glide during under-shoot.

• Premature flap extension/landing gear extension.

• Use of throttle to increase the glide instead ofmerely clearing the engine.

• Forcing the airplane onto the runway in order toavoid overshooting the designated landing spot.

EMERGENCY APPROACHES ANDLANDINGS (SIMULATED)From time to time on dual flights, the instructor shouldgive simulated emergency landings by retarding thethrottle and calling “simulated emergency landing.”The objective of these simulated emergency landingsis to develop the pilot’s accuracy, judgment, planning,procedures, and confidence when little or no power isavailable.

A simulated emergency landing may be given with theairplane in any configuration. When the instructor calls“simulated emergency landing,” the pilot shouldimmediately establish a glide attitude and ensure thatthe flaps and landing gear are in the proper configura-tion for the existing situation. When the proper glidespeed is attained, the nose should then be lowered andthe airplane trimmed to maintain that speed.

A constant gliding speed should be maintained becausevariations of gliding speed nullify all attempts at accu-racy in judgment of gliding distance and the landingspot. The many variables, such as altitude, obstruction,wind direction, landing direction, landing surface andgradient, and landing distance requirements of theairplane will determine the pattern and approach pro-cedures to use.

Utilizing any combination of normal gliding maneuvers,from wings level to spirals, the pilot should eventuallyarrive at the normal key position at a normal traffic pat-tern altitude for the selected landing area. From thispoint on, the approach will be as nearly as possible anormal power-off approach. [Figure 8-29]

With the greater choice of fields afforded by higheraltitudes, the inexperienced pilot may be inclined todelay making a decision, and with considerable alti-tude in which to maneuver, errors in maneuvering andestimation of glide distance may develop.

All pilots should learn to determine the wind directionand estimate its speed from the windsock at the airport,smoke from factories or houses, dust, brush fires, andwindmills.

Once a field has been selected, the student pilot shouldalways be required to indicate it to the instructor.Normally, the student should be required to plan andfly a pattern for landing on the field first elected untilthe instructor terminates the simulated emergency

Figure 8-29. Remain over intended landing area.

Retract Flaps

Base Key PointLower Flaps

Spiral OverLanding Field

8-25

Ch 08.qxd 5/7/04 8:08 AM Page 8-25

landing. This will give the instructor an opportunity toexplain and correct any errors; it will also give the stu-dent an opportunity to see the results of the errors.However, if the student realizes during the approachthat a poor field has been selected—one that wouldobviously result in disaster if a landing were to bemade—and there is a more advantageous field withingliding distance, a change to the better field should bepermitted. The hazards involved in these last-minutedecisions, such as excessive maneuvering at very lowaltitudes, should be thoroughly explained by theinstructor.

Slipping the airplane, using flaps, varying the positionof the base leg, and varying the turn onto finalapproach should be stressed as ways of correcting formisjudgment of altitude and glide angle.

Eagerness to get down is one of the most commonfaults of inexperienced pilots during simulated emer-gency landings. In giving way to this, they forget aboutspeed and arrive at the edge of the field with too muchspeed to permit a safe landing. Too much speed may bejust as dangerous as too little; it results in excessivefloating and overshooting the desired landing spot. Itshould be impressed on the students that they cannotdive at a field and expect to land on it.

During all simulated emergency landings, the engineshould be kept warm and cleared. During a simulatedemergency landing, either the instructor or the studentshould have complete control of the throttle. Thereshould be no doubt as to who has control since manynear accidents have occurred from such misunder-standings.

Every simulated emergency landing approach shouldbe terminated as soon as it can be determined whethera safe landing could have been made. In no caseshould it be continued to a point where it creates anundue hazard or an annoyance to persons or propertyon the ground.

In addition to flying the airplane from the point ofsimulated engine failure to where a reasonable safelanding could be made, the student should also betaught certain emergency cockpit procedures. Thehabit of performing these cockpit procedures shouldbe developed to such an extent that, when an enginefailure actually occurs, the student will check the criti-cal items that would be necessary to get the engineoperating again while selecting a field and planningan approach. Combining the two operations—accomplishing emergency procedures and planning

Figure 8-30. Sample emergency checklist.

8-26

Ch 08.qxd 5/7/04 8:08 AM Page 8-26

and flying the approach—will be difficult for the stu-dent during the early training in emergency landings.

There are definite steps and procedures to be followedin a simulated emergency landing. Although they maydiffer somewhat from the procedures used in an actualemergency, they should be learned thoroughly by thestudent, and each step called out to the instructor. Theuse of a checklist is strongly recommended. Mostairplane manufacturers provide a checklist of theappropriate items. [Figure 8-30]

Critical items to be checked should include the posi-tion of the fuel tank selector, the quantity of fuel in thetank selected, the fuel pressure gauge to see if the elec-tric fuel pump is needed, the position of the mixturecontrol, the position of the magneto switch, and the useof carburetor heat. Many actual emergency landingshave been made and later found to be the result of thefuel selector valve being positioned to an empty tankwhile the other tank had plenty of fuel. It may be wiseto change the position of the fuel selector valve eventhough the fuel gauge indicates fuel in all tanksbecause fuel gauges can be inaccurate. Many actualemergency landings could have been prevented ifthe pilots had developed the habit of checking thesecritical items during flight training to the extent thatit carried over into later flying.

Instruction in emergency procedures should not be lim-ited to simulated emergency landings caused by powerfailures. Other emergencies associated with the operationof the airplane should be explained, demonstrated, andpracticed if practicable. Among these emergencies aresuch occurrences as fire in flight, electrical or hydraulicsystem malfunctions, unexpected severe weatherconditions, engine overheating, imminent fuel

exhaustion, and the emergency operation of airplanesystems and equipment.

FAULTY APPROACHES AND LANDINGS

LOW FINAL APPROACHWhen the base leg is too low, insufficient power is used,landing flaps are extended prematurely, or the velocity ofthe wind is misjudged, sufficient altitude may be lost,which will cause the airplane to be well below the properfinal approach path. In such a situation, the pilot wouldhave to apply considerable power to fly the airplane (atan excessively low altitude) up to the runway threshold.When it is realized the runway will not be reachedunless appropriate action is taken, power must beapplied immediately to maintain the airspeed while thepitch attitude is raised to increase lift and stop thedescent. When the proper approach path has beenintercepted, the correct approach attitude should bereestablished and the power reduced and a stabilizedapproach maintained. [Figure 8-31] DO NOT increasethe pitch attitude without increasing the power, sincethe airplane will decelerate rapidly and may approachthe critical angle of attack and stall. DO NOT retractthe flaps; this will suddenly decrease lift and cause theairplane to sink more rapidly. If there is any doubtabout the approach being safely completed, it is advis-able to EXECUTE AN IMMEDIATE GO-AROUND.

HIGH FINAL APPROACHWhen the final approach is too high, lower the flaps asrequired. Further reduction in power may be necessary,while lowering the nose simultaneously to maintainapproach airspeed and steepen the approach path.[Figure 8-32] When the proper approach path has beenintercepted, adjust the power as required to maintain a

Figure 8-31. Right and wrong methods of correction for low final approach.

8-27

Normal Approach PathAdd Power Nose UpHold Altitude

Wrong (Dragging it in with High Power / High Pitch Altitude)

Intercept Normal GlidepathResume Normal Approach

Ch 08.qxd 5/7/04 8:08 AM Page 8-27

stabilized approach. When steepening the approachpath, however, care must be taken that the descent doesnot result in an excessively high sink rate. If a high sinkrate is continued close to the surface, it may be difficultto slow to a proper rate prior to ground contact. Anysink rate in excess of 800 - 1,000 feet per minute is con-sidered excessive. A go-around should be initiated ifthe sink rate becomes excessive.

SLOW FINAL APPROACHWhen the airplane is flown at a slower-than-normalairspeed on the final approach, the pilot’s judgment ofthe rate of sink (descent) and the height of roundoutwill be difficult. During an excessively slow approach,the wing is operating near the critical angle of attackand, depending on the pitch attitude changes and con-trol usage, the airplane may stall or sink rapidly, con-tacting the ground with a hard impact.

Whenever a slow-speed approach is noted, the pilotshould apply power to accelerate the airplane andincrease the lift to reduce the sink rate and to preventa stall. This should be done while still at a highenough altitude to reestablish the correct approachairspeed and attitude. If too slow and too low, it isbest to EXECUTE A GO-AROUND.

USE OF POWERPower can be used effectively during the approach androundout to compensate for errors in judgment. Powercan be added to accelerate the airplane to increase liftwithout increasing the angle of attack; thus, the descentcan be slowed to an acceptable rate. If the properlanding attitude has been attained and the airplane isonly slightly high, the landing attitude should beheld constant and sufficient power applied to helpease the airplane onto the ground. After the airplanehas touched down, it will be necessary to close the

throttle so the additional thrust and lift will beremoved and the airplane will stay on the ground.

HIGH ROUNDOUTSometimes when the airplane appears to temporarilystop moving downward, the roundout has been madetoo rapidly and the airplane is flying level, too highabove the runway. Continuing the roundout wouldfurther reduce the airspeed, resulting in an increasein angle of attack to the critical angle. This wouldresult in the airplane stalling and dropping hard ontothe runway. To prevent this, the pitch attitude shouldbe held constant until the airplane decelerates enoughto again start descending. Then the roundout can becontinued to establish the proper landing attitude.This procedure should only be used when there isadequate airspeed. It may be necessary to add a slightamount of power to keep the airspeed from decreasingexcessively and to avoid losing lift too rapidly.

Although back-elevator pressure may be relaxedslightly, the nose should not be lowered any percepti-ble amount to make the airplane descend when fairlyclose to the runway unless some power is addedmomentarily. The momentary decrease in lift thatwould result from lowering the nose and decreasingthe angle of attack may be so great that the airplanemight contact the ground with the nosewheel first,which could collapse.

When the proper landing attitude is attained, the air-plane is approaching a stall because the airspeed isdecreasing and the critical angle of attack is beingapproached, even though the pitch attitude is no longerbeing increased. [Figure 8-33]

It is recommended that a GO-AROUND be executedany time it appears the nose must be lowered signifi-cantly or that the landing is in any other way uncertain.

Figure 8-32. Change in glidepath and increase in descent rate for high final approach.

No Flaps

Full Flaps

Steeper Descent Angle

Increased Rate of Descent

8-28

Ch 08.qxd 5/7/04 8:08 AM Page 8-28

8-29

LATE OR RAPID ROUNDOUTStarting the roundout too late or pulling the elevatorcontrol back too rapidly to prevent the airplane fromtouching down prematurely can impose a heavy loadfactor on the wing and cause an accelerated stall.

Suddenly increasing the angle of attack and stalling theairplane during a roundout is a dangerous situationsince it may cause the airplane to land extremely hardon the main landing gear, and then bounce back intothe air. As the airplane contacts the ground, the tail willbe forced down very rapidly by the back-elevator pres-sure and by inertia acting downward on the tail.

Recovery from this situation requires prompt andpositive application of power prior to occurrence ofthe stall. This may be followed by a normal landing ifsufficient runway is available—otherwise the pilotshould EXECUTE A GO-AROUND immediately.

If the roundout is late, the nosewheel may strike therunway first, causing the nose to bounce upward. No

attempt should be made to force the airplane back ontothe ground; a GO-AROUND should be executedimmediately.

FLOATING DURING ROUNDOUTIf the airspeed on final approach is excessive, it willusually result in the airplane floating. [Figure 8-34]Before touchdown can be made, the airplane may bewell past the desired landing point and the availablerunway may be insufficient. When diving an airplaneon final approach to land at the proper point, there willbe an appreciable increase in airspeed. The propertouchdown attitude cannot be established without pro-ducing an excessive angle of attack and lift. This willcause the airplane to gain altitude or balloon.

Any time the airplane floats, judgment of speed,height, and rate of sink must be especially acute. Thepilot must smoothly and gradually adjust the pitch atti-tude as the airplane decelerates to touchdown speedand starts to settle, so the proper landing attitude isattained at the moment of touchdown. The slightest

Figure 8-33. Rounding out too high.

Figure 8-34. Floating during roundout.

Ch 08.qxd 5/7/04 8:08 AM Page 8-29

error in judgment and timing will result in either bal-looning or bouncing.

The recovery from floating will depend on the amountof floating and the effect of any crosswind, as well asthe amount of runway remaining. Since prolongedfloating utilizes considerable runway length, it shouldbe avoided especially on short runways or in strongcrosswinds. If a landing cannot be made on the firstthird of the runway, or the airplane drifts sideways, thepilot should EXECUTE A GO-AROUND.

BALLOONING DURING ROUNDOUTIf the pilot misjudges the rate of sink during a landingand thinks the airplane is descending faster than itshould, there is a tendency to increase the pitch atti-tude and angle of attack too rapidly. This not onlystops the descent, but actually starts the airplaneclimbing. This climbing during the roundout isknown as ballooning. [Figure 8-35] Ballooning canbe dangerous because the height above the ground isincreasing and the airplane may be rapidlyapproaching a stalled condition. The altitude gainedin each instance will depend on the airspeed or thespeed with which the pitch attitude is increased.

When ballooning is slight, a constant landing attitudeshould be held and the airplane allowed to graduallydecelerate and settle onto the runway. Depending onthe severity of ballooning, the use of throttle may behelpful in cushioning the landing. By adding power,thrust can be increased to keep the airspeed fromdecelerating too rapidly and the wings from suddenlylosing lift, but throttle must be closed immediatelyafter touchdown. Remember that torque will be cre-ated as power is applied; therefore, it will be necessaryto use rudder pressure to keep the airplane straight as itsettles onto the runway.

When ballooning is excessive, it is best to EXECUTEA GO-AROUND IMMEDIATELY; DO NOTATTEMPT TO SALVAGE THE LANDING. Powermust be applied before the airplane enters a stalledcondition.

The pilot must be extremely cautious of ballooningwhen there is a crosswind present because the cross-wind correction may be inadvertently released or itmay become inadequate. Because of the lower airspeedafter ballooning, the crosswind affects the airplanemore. Consequently, the wing will have to be loweredeven further to compensate for the increased drift. Itis imperative that the pilot makes certain that theappropriate wing is down and that directional controlis maintained with opposite rudder. If there is anydoubt, or the airplane starts to drift, EXECUTE AGO-AROUND.

BOUNCING DURING TOUCHDOWNWhen the airplane contacts the ground with a sharpimpact as the result of an improper attitude or anexcessive rate of sink, it tends to bounce back into theair. Though the airplane’s tires and shock strutsprovide some springing action, the airplane does notbounce like a rubber ball. Instead, it rebounds intothe air because the wing’s angle of attack wasabruptly increased, producing a sudden addition oflift. [Figure 8-36]

The abrupt change in angle of attack is the result ofinertia instantly forcing the airplane’s tail downwardwhen the main wheels contact the ground sharply. Theseverity of the bounce depends on the airspeed at themoment of contact and the degree to which the angleof attack or pitch attitude was increased.

Since a bounce occurs when the airplane makes con-tact with the ground before the proper touchdown

Figure 8-35. Ballooning during roundout.

8-30

Ch 08.qxd 5/7/04 8:08 AM Page 8-30

8-31

attitude is attained, it is almost invariably accompa-nied by the application of excessive back-elevatorpressure. This is usually the result of the pilot realizingtoo late that the airplane is not in the proper attitudeand attempting to establish it just as the second touch-down occurs.

The corrective action for a bounce is the same as forballooning and similarly depends on its severity. Whenit is very slight and there is no extreme change in theairplane’s pitch attitude, a follow-up landing may beexecuted by applying sufficient power to cushion thesubsequent touchdown, and smoothly adjusting thepitch to the proper touchdown attitude.

In the event a very slight bounce is encountered whilelanding with a crosswind, crosswind correction mustbe maintained while the next touchdown is made.Remember that since the subsequent touchdown willbe made at a slower airspeed, the upwind wing willhave to be lowered even further to compensate fordrift.

Extreme caution and alertness must be exercised anytime a bounce occurs, but particularly when there is acrosswind. Inexperienced pilots will almost invariablyrelease the crosswind correction. When one mainwheel of the airplane strikes the runway, the otherwheel will touch down immediately afterwards, andthe wings will become level. Then, with no crosswindcorrection as the airplane bounces, the wind will causethe airplane to roll with the wind, thus exposing evenmore surface to the crosswind and drifting the airplanemore rapidly.

When a bounce is severe, the safest procedure is toEXECUTE A GO-AROUND IMMEDIATELY. Noattempt to salvage the landing should be made. Full

power should be applied while simultaneously main-taining directional control, and lowering the nose to asafe climb attitude. The go-around procedure shouldbe continued even though the airplane may descendand another bounce may be encountered. It would beextremely foolish to attempt a landing from a badbounce since airspeed diminishes very rapidly in thenose-high attitude, and a stall may occur before asubsequent touchdown could be made.

PORPOISINGIn a bounced landing that is improperly recovered,the airplane comes in nose first setting off a series ofmotions that imitate the jumps and dives of a porpoise—hence the name. [Figure 8-37] The problem is improperairplane attitude at touchdown, sometimes caused byinattention, not knowing where the ground is, mistrim-ming or forcing the airplane onto the runway.

Ground effect decreases elevator control effectivenessand increases the effort required to raise the nose. Notenough elevator or stabilator trim can result in a nose-low contact with the runway and a porpoise develops.

Porpoising can also be caused by improper airspeedcontrol. Usually, if an approach is too fast, the airplanefloats and the pilot tries to force it on the runway whenthe airplane still wants to fly. A gust of wind, a bump inthe runway, or even a slight tug on the control wheelwill send the airplane aloft again.

The corrective action for a porpoise is the same as fora bounce and similarly depends on its severity. Whenit is very slight and there is no extreme change in theairplane’s pitch attitude, a follow-up landing may beexecuted by applying sufficient power to cushion thesubsequent touchdown, and smoothly adjusting thepitch to the proper touchdown attitude.

Small Angleof Attack

Decreasing Angleof Attack

Rapid Increase inAngle of Attack

Normal Angleof Attack

Figure 8-36. Bouncing during touchdown.

Ch 08.qxd 5/7/04 8:08 AM Page 8-31

When a porpoise is severe, the safest procedure is toEXECUTE A GO-AROUND IMMEDIATELY. In asevere porpoise, the airplane’s pitch oscillations canbecome progressively worse, until the airplane strikesthe runway nose first with sufficient force to collapsethe nose gear. Pilot attempts to correct a severe por-poise with flight control and power inputs will mostlikely be untimely and out of sequence with the oscil-lations, and only make the situation worse. No attemptto salvage the landing should be made. Full powershould be applied while simultaneously maintainingdirectional control, and lowering the nose to a safeclimb attitude.

WHEELBARROWINGWhen a pilot permits the airplane weight to becomeconcentrated about the nosewheel during the takeoff orlanding roll, a condition known as wheelbarrowing willoccur. Wheelbarrowing may cause loss of directionalcontrol during the landing roll because braking action isineffective, and the airplane tends to swerve or pivot onthe nosewheel, particularly in crosswind conditions.One of the most common causes of wheelbarrowingduring the landing roll is a simultaneous touchdownof the main and nosewheel, with excessive speed,followed by application of forward pressure on theelevator control. Usually, the situation can be cor-rected by smoothly applying back-elevator pressure.However, if wheelbarrowing is encountered andrunway and other conditions permit, it may be advisableto promptly initiate a go-around. Wheelbarrowing willnot occur if the pilot achieves and maintains the correctlanding attitude, touches down at the proper speed, andgently lowers the nosewheel while losing speed onrollout. If the pilot decides to stay on the ground ratherthan attempt a go-around or if directional control islost, the throttle should be closed and the pitch atti-tude smoothly but firmly rotated to the proper landingattitude. Raise the flaps to reduce lift and to increasethe load on the main wheels for better braking action.

HARD LANDINGWhen the airplane contacts the ground during landings,its vertical speed is instantly reduced to zero. Unlessprovisions are made to slow this vertical speed and

cushion the impact of touchdown, the force of contactwith the ground may be so great it could causestructural damage to the airplane.

The purpose of pneumatic tires, shock absorbing landinggears, and other devices is to cushion the impact and toincrease the time in which the airplane’s vertical descentis stopped. The importance of this cushion may beunderstood from the computation that a 6-inch free fallon landing is roughly equal, to a 340-foot-per-minutedescent. Within a fraction of a second, the airplane mustbe slowed from this rate of vertical descent to zero,without damage.

During this time, the landing gear together with someaid from the lift of the wings must supply whateverforce is needed to counteract the force of the airplane’sinertia and weight. The lift decreases rapidly as theairplane’s forward speed is decreased, and the forceon the landing gear increases by the impact oftouchdown. When the descent stops, the lift will bepractically zero, leaving the landing gear alone tocarry both the airplane’s weight and inertia force.The load imposed at the instant of touchdown mayeasily be three or four times the actual weight of theairplane depending on the severity of contact.

TOUCHDOWN IN A DRIFT OR CRABAt times the pilot may correct for wind drift by crabbingon the final approach. If the roundout and touchdown aremade while the airplane is drifting or in a crab, it willcontact the ground while moving sideways. This willimpose extreme side loads on the landing gear, and ifsevere enough, may cause structural failure.

The most effective method to prevent drift in primarytraining airplanes is the wing-low method. This tech-nique keeps the longitudinal axis of the airplanealigned with both the runway and the direction ofmotion throughout the approach and touchdown.

There are three factors that will cause the longitudinalaxis and the direction of motion to be misalignedduring touchdown: drifting, crabbing, or a combina-tion of both.

Decreasing Angleof Attack

Decreasing Angleof Attack

Rapid Increase inAngle of Attack

Rapid Increase inAngle of Attack

Normal Angleof Attack

Normal Angleof Attack

Figure 8-37. Porpoising.

8-32

Ch 08.qxd 5/7/04 8:08 AM Page 8-32

8-33

If the pilot has not taken adequate corrective action toavoid drift during a crosswind landing, the mainwheels’ tire tread offers resistance to the airplane’ssideward movement in respect to the ground.Consequently, any sidewise velocity of the airplane isabruptly decelerated, with the result that the inertiaforce is as shown in figure 8-38. This creates a momentaround the main wheel when it contacts the ground,tending to overturn or tip the airplane. If the windwardwingtip is raised by the action of this moment, all theweight and shock of landing will be borne by one mainwheel. This could cause structural damage.

Figure 8-38. Drifting during touchdown.

Not only are the same factors present that are attempt-ing to raise a wing, but the crosswind is also acting onthe fuselage surface behind the main wheels, tendingto yaw (weathervane) the airplane into the wind. Thisoften results in a ground loop.

GROUND LOOPA ground loop is an uncontrolled turn during groundoperation that may occur while taxiing or taking off,but especially during the after-landing roll. Drift orweathervaning does not always cause a ground loop,although these things may cause the initial swerve.Careless use of the rudder, an uneven ground surface,or a soft spot that retards one main wheel of the air-plane may also cause a swerve. In any case, the initialswerve tends to make the airplane ground loop,whether it is a tailwheel-type or nosewheel-type.[Figure 8-39]

Nosewheel-type airplanes are somewhat less prone toground loop than tailwheel-type airplanes. Since thecenter of gravity (CG) is located forward of the mainlanding gear on these airplanes, any time a swervedevelops, centrifugal force acting on the CG will tendto stop the swerving action.

If the airplane touches down while drifting or in a crab,the pilot should apply aileron toward the high wing andstop the swerve with the rudder. Brakes should be usedto correct for turns or swerves only when the rudder isinadequate. The pilot must exercise caution whenapplying corrective brake action because it is very easyto overcontrol and aggravate the situation.

If brakes are used, sufficient brake should be appliedon the low-wing wheel (outside of the turn) to stop theswerve. When the wings are approximately level, thenew direction must be maintained until the airplane hasslowed to taxi speed or has stopped.

In nosewheel airplanes, a ground loop is almost alwaysa result of wheelbarrowing. The pilot must be aware thateven though the nosewheel-type airplane is less pronethan the tailwheel-type airplane, virtually every type ofairplane, including large multiengine airplanes, can bemade to ground loop when sufficiently mishandled.

WING RISING AFTER TOUCHDOWNWhen landing in a crosswind, there may be instanceswhen a wing will rise during the after-landing roll. Thismay occur whether or not there is a loss of directional

Wind Force

Center ofGravity

Force ResistingSide Motion

Inertia Force

Weight

Airplane Tipsand Swerves

CG Continues Moving inSame Direction of Drift

Touchdown

Roundout

Roundout

Figure 8-39. Start of a ground loop.

Ch 08.qxd 5/7/04 8:08 AM Page 8-33

8-34

control, depending on the amount of crosswind and thedegree of corrective action.

Any time an airplane is rolling on the ground in acrosswind condition, the upwind wing is receiving agreater force from the wind than the downwind wing.This causes a lift differential. Also, as the upwind wingrises, there is an increase in the angle of attack, whichincreases lift on the upwind wing, rolling the airplanedownwind.

When the effects of these two factors are great enough,the upwind wing may rise even though directionalcontrol is maintained. If no correction is applied, it ispossible that the upwind wing will rise sufficiently tocause the downwind wing to strike the ground.

In the event a wing starts to rise during the landing roll,the pilot should immediately apply more aileron pres-sure toward the high wing and continue to maintaindirection. The sooner the aileron control is applied,the more effective it will be. The further a wing isallowed to rise before taking corrective action, themore airplane surface is exposed to the force of thecrosswind. This diminishes the effectiveness of theaileron.

HYDROPLANINGHydroplaning is a condition that can exist when anairplane is landed on a runway surface contaminatedwith standing water, slush, and/or wet snow.Hydroplaning can have serious adverse effects onground controllability and braking efficiency. Thethree basic types of hydroplaning are dynamichydroplaning, reverted rubber hydroplaning, and vis-cous hydroplaning. Any one of the three can renderan airplane partially or totally uncontrollable anytimeduring the landing roll.

DYNAMIC HYDROPLANINGDynamic hydroplaning is a relatively high-speedphenomenon that occurs when there is a film of wateron the runway that is at least one-tenth inch deep. As thespeed of the airplane and the depth of the water increase,the water layer builds up an increasing resistance todisplacement, resulting in the formation of a wedge ofwater beneath the tire. At some speed, termed thehydroplaning speed (VP), the water pressure equals theweight of the airplane and the tire is lifted off the runwaysurface. In this condition, the tires no longer contribute todirectional control and braking action is nil.

Dynamic hydroplaning is related to tire inflationpressure. Data obtained during hydroplaning tests haveshown the minimum dynamic hydroplaning speed (VP)of a tire to be 8.6 times the square root of the tirepressure in pounds per square inch (PSI). For anairplane with a main tire pressure of 24 pounds,

the calculated hydroplaning speed would beapproximately 42 knots. It is important to note that thecalculated speed referred to above is for the start ofdynamic hydroplaning. Once hydroplaning hasstarted, it may persist to a significantly slower speeddepending on the type being experienced.

REVERTED RUBBER HYDROPLANINGReverted rubber (steam) hydroplaning occurs duringheavy braking that results in a prolonged locked-wheelskid. Only a thin film of water on the runway isrequired to facilitate this type of hydroplaning.

The tire skidding generates enough heat to cause therubber in contact with the runway to revert to itsoriginal uncured state. The reverted rubber acts as aseal between the tire and the runway, and delayswater exit from the tire footprint area. The waterheats and is converted to steam which supports thetire off the runway.

Reverted rubber hydroplaning frequently follows anencounter with dynamic hydroplaning, during whichtime the pilot may have the brakes locked in an attemptto slow the airplane. Eventually the airplane slowsenough to where the tires make contact with therunway surface and the airplane begins to skid. Theremedy for this type of hydroplane is for the pilot torelease the brakes and allow the wheels to spin upand apply moderate braking. Reverted rubberhydroplaning is insidious in that the pilot may notknow when it begins, and it can persist to very slowgroundspeeds (20 knots or less).

VISCOUS HYDROPLANINGViscous hydroplaning is due to the viscous propertiesof water. A thin film of fluid no more than onethousandth of an inch in depth is all that is needed. Thetire cannot penetrate the fluid and the tire rolls on topof the film. This can occur at a much lower speed thandynamic hydroplane, but requires a smooth or smoothacting surface such as asphalt or a touchdown areacoated with the accumulated rubber of past landings.Such a surface can have the same friction coefficientas wet ice.

When confronted with the possibility of hydroplaning,it is best to land on a grooved runway (if available).Touchdown speed should be as slow as possibleconsistent with safety. After the nosewheel islowered to the runway, moderate braking should beapplied. If deceleration is not detected andhydroplaning is suspected, the nose should be raisedand aerodynamic drag utilized to decelerate to apoint where the brakes do become effective.

Proper braking technique is essential. The brakesshould be applied firmly until reaching a point just

Ch 08.qxd 5/7/04 8:08 AM Page 8-34

8-35

short of a skid. At the first sign of a skid, the pilotshould release brake pressure and allow the wheels tospin up. Directional control should be maintained asfar as possible with the rudder. Remember that in a

crosswind, if hydroplaning should occur, thecrosswind will cause the airplane to simultaneouslyweathervane into the wind as well as slide downwind.

Ch 08.qxd 5/7/04 8:08 AM Page 8-35

8-36

Ch 08.qxd 5/7/04 8:08 AM Page 8-36

9-1

PERFORMANCE MANEUVERSPerformance maneuvers are used to develop a highdegree of pilot skill. They aid the pilot in analyzing theforces acting on the airplane and in developing a finecontrol touch, coordination, timing, and division ofattention for precise maneuvering of the airplane.Performance maneuvers are termed “advanced”maneuvers because the degree of skill required forproper execution is normally not acquired until a pilothas obtained a sense of orientation and control feel in“normal” maneuvers. An important benefit ofperformance maneuvers is the sharpening offundamental skills to the degree that the pilot can copewith unusual or unforeseen circumstances occasionallyencountered in normal flight.

Advanced maneuvers are variations and/orcombinations of the basic maneuvers previouslylearned. They embody the same principles andtechniques as the basic maneuvers, but require a higherdegree of skill for proper execution. The student,therefore, who demonstrates a lack of progress in theperformance of advanced maneuvers, is more thanlikely deficient in one or more of the basic maneuvers.The flight instructor should consider breaking theadvanced maneuver down into its component basic

maneuvers in an attempt to identify and correctthe deficiency before continuing with theadvanced maneuver.

STEEP TURNSThe objective of the maneuver is to develop thesmoothness, coordination, orientation, division ofattention, and control techniques necessary for theexecution of maximum performance turns when theairplane is near its performance limits. Smoothness ofcontrol use, coordination, and accuracy of executionare the important features of this maneuver.

The steep turn maneuver consists of a turn in eitherdirection, using a bank angle between 45 to 60°. Thiswill cause an overbanking tendency during whichmaximum turning performance is attained andrelatively high load factors are imposed. Because of thehigh load factors imposed, these turns should beperformed at an airspeed that does not exceed theairplane’s design maneuvering speed (VA). Theprinciples of an ordinary steep turn apply, but as apractice maneuver the steep turns should be continueduntil 360° or 720° of turn have been completed.[Figure 9-1]

Figure 9-1. Steep turns.

Ch 09.qxd 5/7/04 8:14 AM Page 9-1

9-2

An airplane’s maximum turning performance is itsfastest rate of turn and its shortest radius of turn, whichchange with both airspeed and angle of bank. Eachairplane’s turning performance is limited by theamount of power its engine is developing, itslimit load factor (structural strength), and itsaerodynamic characteristics.

The limiting load factor determines the maximumbank, which can be maintained without stalling orexceeding the airplane’s structural limitations. In mostsmall planes, the maximum bank has been found to beapproximately 50° to 60°.

The pilot should realize the tremendous additional loadthat is imposed on an airplane as the bank is increasedbeyond 45°. During a coordinated turn with a 70°bank, a load factor of approximately 3 Gs is placed onthe airplane’s structure. Most general aviation typeairplanes are stressed for approximately 3.8 Gs.

Regardless of the airspeed or the type of airplanesinvolved, a given angle of bank in a turn, during whichaltitude is maintained, will always produce the sameload factor. Pilots must be aware that an additional loadfactor increases the stalling speed at a significantrate—stalling speed increases with the square root ofthe load factor. For example, a light plane that stalls at60 knots in level flight will stall at nearly 85 knots in a60° bank. The pilot’s understanding and observance ofthis fact is an indispensable safety precaution for theperformance of all maneuvers requiring turns.

Before starting the steep turn, the pilot should ensurethat the area is clear of other air traffic since the rate ofturn will be quite rapid. After establishing themanufacturer’s recommended entry speed or thedesign maneuvering speed, the airplane should besmoothly rolled into a selected bank angle between 45to 60°. As the turn is being established, back-elevatorpressure should be smoothly increased to increase theangle of attack. This provides the additional wing liftrequired to compensate for the increasing load factor.

After the selected bank angle has been reached, thepilot will find that considerable force is required on theelevator control to hold the airplane in level flight—tomaintain altitude. Because of this increase in the forceapplied to the elevators, the load factor increasesrapidly as the bank is increased. Additionalback-elevator pressure increases the angle of attack,which results in an increase in drag. Consequently,power must be added to maintain the entry altitudeand airspeed.

Eventually, as the bank approaches the airplane’smaximum angle, the maximum performance orstructural limit is being reached. If this limit isexceeded, the airplane will be subjected to excessivestructural loads, and will lose altitude, or stall. The

limit load factor must not be exceeded, to preventstructural damage.

During the turn, the pilot should not stare at any oneobject. To maintain altitude, as well as orientation,requires an awareness of the relative position of thenose, the horizon, the wings, and the amount of bank.The pilot who references the aircraft’s turn bywatching only the nose will have difficulty holdingaltitude constant; on the other hand, the pilot whowatches the nose, the horizon, and the wings canusually hold altitude within a few feet. If the altitudebegins to increase, or decrease, relaxing or increasingthe back-elevator pressure will be required asappropriate. This may also require a power adjustmentto maintain the selected airspeed. A small increase ordecrease of 1 to 3° of bank angle may be used tocontrol small altitude deviations. All bank anglechanges should be done with coordinated use ofaileron and rudder.

The rollout from the turn should be timed so that thewings reach level flight when the airplane is exactlyon the heading from which the maneuver was started.While the recovery is being made, back-elevatorpressure is gradually released and power reduced, asnecessary, to maintain the altitude and airspeed.

Common errors in the performance of steep turns are:

• Failure to adequately clear the area.

• Excessive pitch change during entry or recovery.

• Attempts to start recovery prematurely.

• Failure to stop the turn on a precise heading.

• Excessive rudder during recovery, resulting inskidding.

• Inadequate power management.

• Inadequate airspeed control.

• Poor coordination.

• Gaining altitude in right turns and/or losingaltitude in left turns.

• Failure to maintain constant bank angle.

• Disorientation.

• Attempting to perform the maneuverby instrument reference rather than visualreference.

• Failure to scan for other traffic during themaneuver.

Ch 09.qxd 5/7/04 8:14 AM Page 9-2

9-3

STEEP SPIRALThe objective of this maneuver is to improve pilottechniques for airspeed control, wind drift control,planning, orientation, and division of attention. Thesteep spiral is not only a valuable flight trainingmaneuver, but it has practical application in providinga procedure for dissipating altitude while remainingover a selected spot in preparation for landing,especially for emergency forced landings.

A steep spiral is a constant gliding turn, during which aconstant radius around a point on the ground ismaintained similar to the maneuver, turns around apoint. The radius should be such that the steepest bankwill not exceed 60°. Sufficient altitude must beobtained before starting this maneuver so that thespiral may be continued through a series of at leastthree 360° turns. [Figure 9-2] The maneuver shouldnot be continued below 1,000 feet above the surfaceunless performing an emergency landing inconjunction with the spiral.

Operating the engine at idle speed for a prolongedperiod during the glide may result in excessive enginecooling or spark plug fouling. The engine should becleared periodically by briefly advancing the throttleto normal cruise power, while adjusting the pitchattitude to maintain a constant airspeed. Preferably,this should be done while headed into the wind tominimize any variation in groundspeed and radiusof turn.

After the throttle is closed and gliding speed isestablished, a gliding spiral should be started and a turnof constant radius maintained around the selected spoton the ground. This will require correction for winddrift by steepening the bank on downwind headingsand shallowing the bank on upwind headings, just as inthe maneuver, turns around a point. During thedescending spiral, the pilot must judge the directionand speed of the wind at different altitudes and makeappropriate changes in the angle of bank to maintain auniform radius.

A constant airspeed should also be maintainedthroughout the maneuver. Failure to hold the airspeedconstant will cause the radius of turn and necessaryangle of bank to vary excessively. On the downwindside of the maneuver, the steeper the bank angle, thelower the pitch attitude must be to maintain a givenairspeed. Conversely, on the upwind side, as the bankangle becomes shallower, the pitch attitude must beraised to maintain the proper airspeed. This isnecessary because the airspeed tends to change as thebank is changed from shallow to steep to shallow.

During practice of the maneuver, the pilot shouldexecute three turns and roll out toward a definite objector on a specific heading. During the rollout,smoothness is essential, and the use of controls mustbe so coordinated that no increase or decrease of speedresults when the straight glide is resumed.

Figure 9-2. Steep spiral.

Ch 09.qxd 5/7/04 8:14 AM Page 9-3

9-4

Common errors in the performance of steep spirals are:

• Failure to adequately clear the area.

• Failure to maintain constant airspeed.

• Poor coordination, resulting in skidding and/orslipping.

• Inadequate wind drift correction.

• Failure to coordinate the controls so that noincrease/decrease in speed results when straightglide is resumed.

• Failure to scan for other traffic.

• Failure to maintain orientation.

CHANDELLEThe objective of this maneuver is to develop the pilot’scoordination, orientation, planning, and accuracy ofcontrol during maximum performance flight.

A chandelle is a maximum performance climbing turnbeginning from approximately straight-and-levelflight, and ending at the completion of a precise 180°of turn in a wings-level, nose-high attitude at theminimum controllable airspeed. [Figure 9-3] Themaneuver demands that the maximum flightperformance of the airplane be obtained; the airplaneshould gain the most altitude possible for a givendegree of bank and power setting without stalling.

Since numerous atmospheric variables beyond controlof the pilot will affect the specific amount of altitudegained, the quality of the performance of themaneuver is not judged solely on the altitude gain, butby the pilot’s overall proficiency as it pertains to climbperformance for the power/bank combination used,and to the elements of piloting skill demonstrated.

Prior to starting a chandelle, the flaps and gear (ifretractable) should be in the UP position, power set tocruise condition, and the airspace behind and aboveclear of other air traffic. The maneuver should beentered from straight-and-level flight (or a shallowdive) and at a speed no greater than the maximumentry speed recommended by the manufacturer—inmost cases not above the airplane’s designmaneuvering speed (VA).

After the appropriate airspeed and power setting havebeen established, the chandelle is started by smoothlyentering a coordinated turn with an angle of bankappropriate for the airplane being flown. Normally,this angle of bank should not exceed approximately30°. After the appropriate bank is established, aclimbing turn should be started by smoothly applyingback-elevator pressure to increase the pitch attitude ata constant rate and to attain the highest pitch attitudeas 90° of turn is completed. As the climb is initiated inairplanes with fixed-pitch propellers, full throttle maybe applied, but is applied gradually so that themaximum allowable r.p.m. is not exceeded. Inairplanes with constant-speed propellers, power maybe left at the normal cruise setting.

Figure 9-3. Chandelle.

Ch 09.qxd 5/7/04 8:14 AM Page 9-4

9-5

Once the bank has been established, the angle of bankshould remain constant until 90° of turn is completed.Although the degree of bank is fixed during thisclimbing turn, it may appear to increase and, in fact,actually will tend to increase if allowed to do so as themaneuver continues.

When the turn has progressed 90° from the originalheading, the pilot should begin rolling out of the bankat a constant rate while maintaining a constant-pitchattitude. Since the angle of bank will be decreasingduring the rollout, the vertical component of lift willincrease slightly. For this reason, it may be necessaryto release a slight amount of back-elevator pressure inorder to keep the nose of the airplane from risinghigher.

As the wings are being leveled at the completion of180° of turn, the pitch attitude should be noted bychecking the outside references and the attitudeindicator. This pitch attitude should be heldmomentarily while the airplane is at the minimumcontrollable airspeed. Then the pitch attitude may begently reduced to return to straight-and-levelcruise flight.

Since the airspeed is constantly decreasing throughoutthe maneuver, the effects of engine torque becomemore and more prominent. Therefore, right-rudderpressure is gradually increased to control yaw andmaintain a constant rate of turn and to keep the airplanein coordinated flight. The pilot should maintaincoordinated flight by the feel of pressures beingapplied on the controls and by the ball instrument ofthe turn-and-slip indicator. If coordinated flight isbeing maintained, the ball will remain in the center ofthe race.

To roll out of a left chandelle, the left aileron must belowered to raise the left wing. This creates more dragthan the aileron on the right wing, resulting in atendency for the airplane to yaw to the left. With thelow airspeed at this point, torque effect tries to makethe airplane yaw to the left even more. Thus, there aretwo forces pulling the airplane’s nose to the left—aileron drag and torque. To maintain coordinatedflight, considerable right-rudder pressure is requiredduring the rollout to overcome the effects of ailerondrag and torque.

In a chandelle to the right, when control pressure isapplied to begin the rollout, the aileron on the rightwing is lowered. This creates more drag on that wingand tends to make the airplane yaw to the right. At thesame time, the effect of torque at the lower airspeed iscausing the airplane’s nose to yaw to the left. Thus,aileron drag pulling the nose to the right and torquepulling to the left, tend to neutralize each other. If

excessive left-rudder pressure is applied, the rolloutwill be uncoordinated.

The rollout to the left can usually be accomplishedwith very little left rudder, since the effects of ailerondrag and torque tend to neutralize each other.Releasing some right rudder, which has been appliedto correct for torque, will normally give the same effectas applying left-rudder pressure. When the wingsbecome level and the ailerons are neutralized, theaileron drag disappears. Because of the low airspeedand high power, the effects of torque become the moreprominent force and must continue to be controlledwith rudder pressure.

A rollout to the left is accomplished mainly byapplying aileron pressure. During the rollout,right-rudder pressure should be gradually released, andleft rudder applied only as necessary to maintaincoordination. Even when the wings are level andaileron pressure is released, right-rudder pressure mustbe held to counteract torque and hold the nose straight.

Common errors in the performance of chandelles are:

• Failure to adequately clear the area.

• Too shallow an initial bank, resulting in a stall.

• Too steep an initial bank, resulting in failure togain maximum performance.

• Allowing the actual bank to increase after estab-lishing initial bank angle.

• Failure to start the recovery at the 90° point inthe turn.

• Allowing the pitch attitude to increase as thebank is rolled out during the second 90° of turn.

• Removing all of the bank before the 180° pointis reached.

• Nose low on recovery, resulting in too muchairspeed.

• Control roughness.

• Poor coordination (slipping or skidding).

• Stalling at any point during the maneuver.

• Execution of a steep turn instead of a climbingmaneuver.

• Failure to scan for other aircraft.

• Attempting to perform the maneuver byinstrument reference rather than visual reference.

Ch 09.qxd 5/7/04 8:14 AM Page 9-5

9-6

LAZY EIGHTThe lazy eight is a maneuver designed to developperfect coordination of controls through a wide rangeof airspeeds and altitudes so that certain accuracypoints are reached with planned attitude and airspeed.In its execution, the dive, climb, and turn are allcombined, and the combinations are varied and appliedthroughout the performance range of the airplane. It isthe only standard flight training maneuver duringwhich at no time do the forces on the controlsremain constant.

The lazy eight as a training maneuver has great valuesince constantly varying forces and attitudes arerequired. These forces must be constantly coordinated,due not only to the changing combinations of banks,dives, and climbs, but also to the constantly varyingairspeed. The maneuver helps develop subconsciousfeel, planning, orientation, coordination, and speedsense. It is not possible to do a lazy eight mechanically,because the control pressures required for perfectcoordination are never exactly the same.

This maneuver derives its name from the manner inwhich the extended longitudinal axis of the airplane ismade to trace a flight pattern in the form of a figure 8lying on its side (a lazy 8). [Figure 9-4]

A lazy eight consists of two 180° turns, in oppositedirections, while making a climb and a descent in asymmetrical pattern during each of the turns. At notime throughout the lazy eight is the airplane flownstraight and level; instead, it is rolled directly from onebank to the other with the wings level only at the

moment the turn is reversed at the completion of each180° change in heading.

As an aid to making symmetrical loops of the 8 duringeach turn, prominent reference points should beselected on the horizon. The reference points selectedshould be 45°, 90°, and 135° from the direction inwhich the maneuver is begun.

Prior to performing a lazy eight, the airspace behindand above should be clear of other air traffic. Themaneuver should be entered from straight-and-levelflight at normal cruise power and at the airspeedrecommended by the manufacturer or at the airplane’sdesign maneuvering speed.

The maneuver is started from level flight with agradual climbing turn in the direction of the 45°reference point. The climbing turn should be plannedand controlled so that the maximum pitch-up attitudeis reached at the 45° point. The rate of rolling into thebank must be such as to prevent the rate of turn frombecoming too rapid. As the pitch attitude is raised, theairspeed decreases, causing the rate of turn to increase.Since the bank also is being increased, it too causesthe rate of turn to increase. Unless the maneuver isbegun with a slow rate of roll, the combination ofincreasing pitch and increasing bank will cause therate of turn to be so rapid that the 45° reference pointwill be reached before the highest pitch attitudeis attained.

At the 45° point, the pitch attitude should be atmaximum and the angle of bank continuing to

Figure 9-4. Lazy eight.

Ch 09.qxd 5/7/04 8:14 AM Page 9-6

9-7

increase. Also, at the 45° point, the pitch attitudeshould start to decrease slowly toward the horizon andthe 90° reference point. Since the airspeed is stilldecreasing, right-rudder pressure will have to beapplied to counteract torque.

As the airplane’s nose is being lowered toward the 90°reference point, the bank should continue to increase.Due to the decreasing airspeed, a slight amount ofopposite aileron pressure may be required to preventthe bank from becoming too steep. When the airplanecompletes 90° of the turn, the bank should be at themaximum angle (approximately 30°), the airspeedshould be at its minimum (5 to 10 knots above stallspeed), and the airplane pitch attitude should bepassing through level flight. It is at this time that animaginary line, extending from the pilot’s eye andparallel to the longitudinal axis of the airplane, passesthrough the 90° reference point.

Lazy eights normally should be performed with nomore than approximately a 30° bank. Steeper banksmay be used, but control touch and technique must bedeveloped to a much higher degree than when themaneuver is performed with a shallower bank.

The pilot should not hesitate at this point but shouldcontinue to fly the airplane into a descending turn sothat the airplane’s nose describes the same size loopbelow the horizon as it did above. As the pilot’s

reference line passes through the 90° point, the bankshould be decreased gradually, and the airplane’s noseallowed to continue lowering. When the airplane hasturned 135°, the nose should be in its lowest pitchattitude. The airspeed will be increasing during thisdescending turn, so it will be necessary to graduallyrelax rudder and aileron pressure and tosimultaneously raise the nose and roll the wings level.As this is being accomplished, the pilot should note theamount of turn remaining and adjust the rate of rolloutand pitch change so that the wings become level andthe original airspeed is attained in level flight just asthe 180° point is reached. Upon returning to thestarting altitude and the 180° point, a climbing turnshould be started immediately in the opposite directiontoward the selected reference points to complete thesecond half of the eight in the same manner as the firsthalf. [Figure 9-5]

Due to the decreasing airspeed, considerable right-rudder pressure is gradually applied to counteracttorque at the top of the eight in both the right and leftturns. The pressure will be greatest at the point oflowest airspeed.

More right-rudder pressure will be needed during theclimbing turn to the right than in the turn to the leftbecause more torque correction is needed to preventyaw from decreasing the rate of turn. In the leftclimbing turn, the torque will tend to contribute to the

90° POINT1. BANK APPROX 30°2. MINIMUM SPEED3. MAXIMUM ALTITUDE4. LEVEL PITCH ATTITUDE

135° POINT1. MAX. PITCH-DOWN2. BANK 15°(APPROX.)

45° POINT1. MAX. PITCH-UP ATTITUDE2. BANK 15° (APPROX.)

ENTRY:1. LEVEL FLIGHT2. MANEUVERING OR CRUISE SPEED WHICHEVER IS LESS OR MANUFACTURER'S RECOMMENDED SPEED.

180° POINT 1. LEVEL FLIGHT2. ENTRY AIRSPEED3. ALTITUDE SAME AS ENTRY ALTITUDE

Figure 9-5. Lazy eight.

Ch 09.qxd 5/7/04 8:14 AM Page 9-7

9-8

turn; consequently, less rudder pressure is needed. Itwill be noted that the controls are slightly crossed inthe right climbing turn because of the need for leftaileron pressure to prevent overbanking and rightrudder to overcome torque.

The correct power setting for the lazy eight is thatwhich will maintain the altitude for the maximum andminimum airspeeds used during the climbs anddescents of the eight. Obviously, if excess power wereused, the airplane would have gained altitude when themaneuver is completed; if insufficient power wereused, altitude would have been lost.

Common errors in the performance of lazy eights are:

• Failure to adequately clear the area.

• Using the nose, or top of engine cowl, instead ofthe true longitudinal axis, resulting inunsymmetrical loops.

• Watching the airplane instead of thereference points.

• Inadequate planning, resulting in the peaks of theloops both above and below the horizon notcoming in the proper place.

• Control roughness, usually caused by attemptsto counteract poor planning.

• Persistent gain or loss of altitude with thecompletion of each eight.

• Attempting to perform the maneuverrhythmically, resulting in poor patternsymmetry.

• Allowing the airplane to “fall” out of the tops ofthe loops rather than flying the airplane throughthe maneuver.

• Slipping and/or skidding.

• Failure to scan for other traffic.

Ch 09.qxd 5/7/04 8:14 AM Page 9-8

NIGHT VISIONGenerally, most pilots are poorly informed about nightvision. Human eyes never function as effectively atnight as the eyes of animals with nocturnal habits, butif humans learn how to use their eyes correctly andknow their limitations, night vision can be improvedsignificantly. There are several reasons for training touse the eyes correctly.

One reason is the mind and eyes act as a team for a per-son to see well; both team members must be usedeffectively. The construction of the eyes is such that tosee at night they are used differently than during theday. Therefore, it is important to understand the eye’sconstruction and how the eye is affected by darkness.

Innumerable light-sensitive nerves, called “cones” and“rods,” are located at the back of the eye or retina, alayer upon which all images are focused. These nervesconnect to the cells of the optic nerve, which transmitsmessages directly to the brain. The cones are located inthe center of the retina, and the rods are concentratedin a ring around the cones. [Figure 10-1]

The function of the cones is to detect color, details, andfaraway objects. The rods function when something isseen out of the corner of the eye or peripheral vision.They detect objects, particularly those that are moving,but do not give detail or color—only shades of gray.Both the cones and the rods are used for vision duringdaylight.

Although there is not a clear-cut division of function,the rods make night vision possible. The rods andcones function in daylight and in moonlight, but in theabsence of normal light, the process of night vision isplaced almost entirely on the rods.

The fact that the rods are distributed in a band aroundthe cones and do not lie directly behind the pupilsmakes off-center viewing (looking to one side of anobject) important during night flight. During daylight,an object can be seen best by looking directly at it, butat night a scanning procedure to permit off-centerviewing of the object is more effective. Therefore, thepilot should consciously practice this scanning proce-dure to improve night vision.

The eye’s adaptation to darkness is another importantaspect of night vision. When a dark room is entered, itis difficult to see anything until the eyes becomeadjusted to the darkness. Most everyone has experi-enced this after entering a darkened movie theater. Inthis process, the pupils of the eyes first enlarge toreceive as much of the available light as possible. Afterapproximately 5 to 10 minutes, the cones becomeadjusted to the dim light and the eyes become 100

Cones for:• Color• Detail• Day

Rods for:• Gray• Peripheral• Day & Night

Area of BestDay Vision

Area of BestNight Vision

Area of BestNight Vision

Figure 10-1. Rods and cones.

10-1

Ch 10.qxd 7/13/04 11:10 AM Page 10-1

times more sensitive to the light than they were beforethe dark room was entered. Much more time, about 30minutes, is needed for the rods to become adjusted todarkness, but when they do adjust, they are about100,000 times more sensitive to light than they were inthe lighted area. After the adaptation process is com-plete, much more can be seen, especially if the eyes areused correctly.

After the eyes have adapted to the dark, the entireprocess is reversed when entering a lighted room. Theeyes are first dazzled by the brightness, but becomecompletely adjusted in a very few seconds, thereby los-ing their adaptation to the dark. Now, if the dark roomis reentered, the eyes again go through the long processof adapting to the darkness.

The pilot before and during night flight must considerthe adaptation process of the eyes. First, the eyesshould be allowed to adapt to the low level of lightand then they should be kept adapted. After the eyeshave become adapted to the darkness, the pilot shouldavoid exposing them to any bright white light thatwill cause temporary blindness and could result inserious consequences.

Temporary blindness, caused by an unusually brightlight, may result in illusions or after images until theeyes recover from the brightness. The brain createsthese illusions reported by the eyes. This results inmisjudging or incorrectly identifying objects, such asmistaking slanted clouds for the horizon or populatedareas for a landing field. Vertigo is experienced as afeeling of dizziness and imbalance that can create orincrease illusions. The illusions seem very real andpilots at every level of experience and skill can beaffected. Recognizing that the brain and eyes can playtricks in this manner is the best protection for flying atnight.

Good eyesight depends upon physical condition.Fatigue, colds, vitamin deficiency, alcohol, stimulants,smoking, or medication can seriously impair vision.Keeping these facts in mind and taking adequate pre-cautions should safeguard night vision.

In addition to the principles previously discussed, thefollowing items will aid in increasing night visioneffectiveness.

• Adapt the eyes to darkness prior to flight andkeep them adapted. About 30 minutes is neededto adjust the eyes to maximum efficiency afterexposure to a bright light.

• If oxygen is available, use it during night flying.Keep in mind that a significant deterioration innight vision can occur at cabin altitudes as low as5,000 feet.

• Close one eye when exposed to bright light tohelp avoid the blinding effect.

• Do not wear sunglasses after sunset.

• Move the eyes more slowly than in daylight.

• Blink the eyes if they become blurred.

• Concentrate on seeing objects.

• Force the eyes to view off center.

• Maintain good physical condition.

• Avoid smoking, drinking, and using drugs thatmay be harmful.

NIGHT ILLUSIONSIn addition to night vision limitations, pilots should beaware that night illusions could cause confusion andconcerns during night flying. The following discus-sion covers some of the common situations that causeillusions associated with night flying.

On a clear night, distant stationary lights can be mis-taken for stars or other aircraft. Even the northernlights can confuse a pilot and indicate a false horizon.Certain geometrical patterns of ground lights, such asa freeway, runway, approach, or even lights on a mov-ing train can cause confusion. Dark nights tend toeliminate reference to a visual horizon. As a result,pilots need to rely less on outside references at nightand more on flight and navigation instruments.

Visual autokinesis can occur when a pilot stares at asingle light source for several seconds on a dark night.The result is that the light will appear to be moving.The autokinesis effect will not occur if the pilotexpands the visual field. It is a good procedure not tobecome fixed on one source of light.

Distractions and problems can result from a flickeringlight in the cockpit, anticollision light, strobe lights,or other aircraft lights and can cause flicker vertigo. Ifcontinuous, the possible physical reactions can benausea, dizziness, grogginess, unconsciousness,headaches, or confusion. The pilot should try to elim-inate any light source causing blinking or flickeringproblems in the cockpit.

A black-hole approach occurs when the landing ismade from over water or non-lighted terrain where therunway lights are the only source of light. Withoutperipheral visual cues to help, pilots will have troubleorientating themselves relative to Earth. The runwaycan seem out of position (downsloping or upsloping)and in the worse case, results in landing short of the

10-2

Ch 10.qxd 7/13/04 11:10 AM Page 10-2

runway. If an electronic glide slope or visual approachslope indicator (VASI) is available, it should be used.If navigation aids (NAVAIDs) are unavailable, carefulattention should be given to using the flight instru-ments to assist in maintaining orientation and a normalapproach. If at any time the pilot is unsure of his or herposition or attitude, a go-around should be executed.

Bright runway and approach lighting systems, espe-cially where few lights illuminate the surroundingterrain, may create the illusion of less distance to therunway. In this situation, the tendency is to fly ahigher approach. Also, when flying over terrain withonly a few lights, it will make the runway recede orappear farther away. With this situation, the tendencyis common to fly a lower-than-normal approach. Ifthe runway has a city in the distance on higher ter-rain, the tendency will be to fly a lower-than-normalapproach. A good review of the airfield layout andboundaries before initiating any approach will helpthe pilot maintain a safe approach angle.

Illusions created by runway lights result in a variety ofproblems. Bright lights or bold colors advance the run-way, making it appear closer.

Night landings are further complicated by the difficultyof judging distance and the possibility of confusingapproach and runway lights. For example, when a dou-ble row of approach lights joins the boundary lights ofthe runway, there can be confusion where the approachlights terminate and runway lights begin. Under certainconditions, approach lights can make the aircraft seemhigher in a turn to final, than when its wings are level.

PILOT EQUIPMENTBefore beginning a night flight, carefully considerpersonal equipment that should be readily availableduring the flight. At least one reliable flashlight isrecommended as standard equipment on all nightflights. Remember to place a spare set of batteries inthe flight kit. A D-cell size flashlight with a bulbswitching mechanism that can be used to select whiteor red light is preferable. The white light is used whileperforming the preflight visual inspection of the airplane,and the red light is used when performing cockpit opera-tions. Since the red light is nonglaring, it will not impairnight vision. Some pilots prefer two flashlights, onewith a white light for preflight, and the other a pen-light type with a red light. The latter can be suspendedby a string from around the neck to ensure the light isalways readily available. One word of caution; if a redlight is used for reading an aeronautical chart, the redfeatures of the chart will not show up.

Aeronautical charts are essential for night cross-coun-try flight and, if the intended course is near the edge ofthe chart, the adjacent chart should also be available.

The lights of cities and towns can be seen at surprisingdistances at night, and if this adjacent chart is not avail-able to identify those landmarks, confusion couldresult. Regardless of the equipment used, organizationof the cockpit eases the burden on the pilot andenhances safety.

AIRPLANE EQUIPMENT AND LIGHTINGTitle 14 of the Code of Federal Regulations (14 CFR)part 91 specifies the basic minimum airplane equip-ment required for night flight. This equipment includesonly basic instruments, lights, electrical energy source,and spare fuses.

The standard instruments required for instrumentflight under 14 CFR part 91 are a valuable asset foraircraft control at night. An anticollision light system,including a flashing or rotating beacon and positionlights, is required airplane equipment. Airplane posi-tion lights are arranged similar to those of boats andships. A red light is positioned on the left wingtip, agreen light on the right wingtip, and a white light onthe tail. [Figure 10-2]

Figure 10-2. Position lights.

This arrangement provides a means by which pilotscan determine the general direction of movement ofother airplanes in flight. If both a red and green light ofanother aircraft were observed, the airplane would beflying toward the pilot, and could be on a collisioncourse.

Landing lights are not only useful for taxi, takeoffs,and landings, but also provide a means by which air-planes can be seen at night by other pilots. The FederalAviation Administration (FAA) has initiated a volun-tary pilot safety program called “Operation LightsON.” The “lights on” idea is to enhance the “see andbe seen” concept of averting collisions both in the air

10-3

Ch 10.qxd 7/13/04 11:10 AM Page 10-3

and on the ground, and to reduce the potential for birdstrikes. Pilots are encouraged to turn on their landinglights when operating within 10 miles of an airport.This is for both day and night, or in conditions ofreduced visibility. This should also be done in areaswhere flocks of birds may be expected.

Although turning on aircraft lights supports the see andbe seen concept, pilots should not become complacentabout keeping a sharp lookout for other aircraft. Mostaircraft lights blend in with the stars or the lights of thecities at night and go unnoticed unless a consciouseffort is made to distinguish them from other lights.

AIRPORT AND NAVIGATION LIGHTING AIDSThe lighting systems used for airports, runways,obstructions, and other visual aids at night are otherimportant aspects of night flying.

Lighted airports located away from congested areascan be identified readily at night by the lights outliningthe runways. Airports located near or within largecities are often difficult to identify in the maze oflights. It is important not to only know the exact loca-tion of an airport relative to the city, but also to be ableto identify these airports by the characteristics of theirlighting pattern.

Aeronautical lights are designed and installed in a vari-ety of colors and configurations, each having its ownpurpose. Although some lights are used only duringlow ceiling and visibility conditions, this discussionincludes only the lights that are fundamental to visualflight rules (VFR) night operation.

It is recommended that prior to a night flight, andparticularly a cross-country night flight, the pilot checkthe availability and status of lighting systems at thedestination airport. This information can be found onaeronautical charts and in the Airport/FacilityDirectory. The status of each facility can be deter-mined by reviewing pertinent Notices to Airmen(NOTAMs).

A rotating beacon is used to indicate the location ofmost airports. The beacon rotates at a constant speed,thus producing what appears to be a series of lightflashes at regular intervals. These flashes may be oneor two different colors that are used to identify varioustypes of landing areas. For example:

• Lighted civilian land airports—alternating whiteand green.

• Lighted civilian water airports—alternatingwhite and yellow.

• Lighted military airports—alternating white andgreen, but are differentiated from civil airports

by dual peaked (two quick) white flashes, thengreen.

Beacons producing red flashes indicate obstructions orareas considered hazardous to aerial navigation.Steady burning red lights are used to mark obstruc-tions on or near airports and sometimes to supplementflashing lights on en route obstructions. High intensityflashing white lights are used to mark some supportingstructures of overhead transmission lines that stretchacross rivers, chasms, and gorges. These high intensitylights are also used to identify tall structures, such aschimneys and towers.

As a result of the technological advancements inaviation, runway lighting systems have becomequite sophisticated to accommodate takeoffs andlandings in various weather conditions. However,the pilot whose flying is limited to VFR only needsto be concerned with the following basic lighting ofrunways and taxiways.

The basic runway lighting system consists of twostraight parallel lines of runway-edge lights defin-ing the lateral limits of the runway. These lights areaviation white, although aviation yellow may besubstituted for a distance of 2,000 feet from the farend of the runway to indicate a caution zone. Atsome airports, the intensity of the runway-edgelights can be adjusted to satisfy the individual needsof the pilot. The length limits of the runway aredefined by straight lines of lights across the runwayends. At some airports, the runway threshold lightsare aviation green, and the runway end lights areaviation red.

At many airports, the taxiways are also lighted. A taxi-way-edge lighting system consists of blue lights thatoutline the usable limits of taxi paths.

PREPARATION AND PREFLIGHTNight flying requires that pilots be aware of, and oper-ate within, their abilities and limitations. Althoughcareful planning of any flight is essential, night flyingdemands more attention to the details of preflightpreparation and planning.

Preparation for a night flight should include a thoroughreview of the available weather reports and forecastswith particular attention given to temperature/dewpointspread. A narrow temperature/dewpoint spread mayindicate the possibility of ground fog. Emphasisshould also be placed on wind direction and speed,since its effect on the airplane cannot be as easilydetected at night as during the day.

On night cross-country flights, appropriate aero-nautical charts should be selected, including the

10-4

Ch 10.qxd 7/13/04 11:10 AM Page 10-4

appropriate adjacent charts. Course lines should bedrawn in black to be more distinguishable.

Prominently lighted checkpoints along the preparedcourse should be noted. Rotating beacons at airports,lighted obstructions, lights of cities or towns, andlights from major highway traffic all provide excellentvisual checkpoints. The use of radio navigation aidsand communication facilities add significantly to thesafety and efficiency of night flying.

All personal equipment should be checked prior toflight to ensure proper functioning. It is very discon-certing to find, at the time of need, that a flashlight, forexample, does not work.

All airplane lights should be turned ON momentarilyand checked for operation. Position lights can bechecked for loose connections by tapping the light fix-ture. If the lights blink while being tapped, furtherinvestigation to determine the cause should be madeprior to flight.

The parking ramp should be examined prior to enter-ing the airplane. During the day, it is quite easy to seestepladders, chuckholes, wheel chocks, and otherobstructions, but at night it is more difficult. A checkof the area can prevent taxiing mishaps.

STARTING,TAXIING, AND RUNUPAfter the pilot is seated in the cockpit and prior to start-ing the engine, all items and materials to be used on theflight should be arranged in such a manner that theywill be readily available and convenient to use.

Extra caution should be taken at night to assure thepropeller area is clear. Turning the rotating beacon ON,or flashing the airplane position lights will serve toalert persons nearby to remain clear of the propeller.To avoid excessive drain of electrical current from thebattery, it is recommended that unnecessary electricalequipment be turned OFF until after the engine hasbeen started.

After starting and before taxiing, the taxi or landinglight should be turned ON. Continuous use of the land-ing light with r.p.m. power settings normally used fortaxiing may place an excessive drain on the airplane’selectrical system. Also, overheating of the landing lightcould become a problem because of inadequate airflowto carry the heat away. Landing lights should be usedas necessary while taxiing. When using landing lights,consideration should be given to not blinding otherpilots. Taxi slowly, particularly in congested areas. Iftaxi lines are painted on the ramp or taxiway, theselines should be followed to ensure a proper path alongthe route.

The before takeoff and runup should be performedusing the checklist. During the day, forward movement

of the airplane can be detected easily. At night, theairplane could creep forward without being noticedunless the pilot is alert for this possibility. Hold orlock the brakes during the runup and be alert for anyforward movement.

TAKEOFF AND CLIMBNight flying is very different from day flying anddemands more attention of the pilot. The most notice-able difference is the limited availability of outsidevisual references. Therefore, flight instruments shouldbe used to a greater degree in controlling the airplane.This is particularly true on night takeoffs and climbs.The cockpit lights should be adjusted to a minimumbrightness that will allow the pilot to read the instru-ments and switches and yet not hinder the pilot’s out-side vision. This will also eliminate light reflections onthe windshield and windows.

After ensuring that the final approach and runway areclear of other air traffic, or when cleared for takeoff bythe tower, the landing lights and taxi lights should beturned ON and the airplane lined up with the centerlineof the runway. If the runway does not have centerlinelighting, use the painted centerline and the runway-edge lights. After the airplane is aligned, the headingindicator should be noted or set to correspond to theknown runway direction. To begin the takeoff, thebrakes should be released and the throttle smoothlyadvanced to maximum allowable power. As the air-plane accelerates, it should be kept moving straightahead between and parallel to the runway-edge lights.

The procedure for night takeoffs is the same as for nor-mal daytime takeoffs except that many of the runwayvisual cues are not available. Therefore, the flightinstruments should be checked frequently during thetakeoff to ensure the proper pitch attitude, heading, andairspeed are being attained. As the airspeed reaches thenormal lift-off speed, the pitch attitude should beadjusted to that which will establish a normal climb.This should be accomplished by referring to both out-side visual references, such as lights, and to the flightinstruments. [Figure 10-3]

Figure 10-3. Establish a positive climb.

10-5

Ch 10.qxd 7/13/04 11:10 AM Page 10-5

10-6

After becoming airborne, the darkness of night oftenmakes it difficult to note whether the airplane is get-ting closer to or farther from the surface. To ensure theairplane continues in a positive climb, be sure a climbis indicated on the attitude indicator, vertical speedindicator (VSI), and altimeter. It is also important toensure the airspeed is at best climb speed.

Necessary pitch and bank adjustments should be madeby referencing the attitude and heading indicators. It isrecommended that turns not be made until reaching asafe maneuvering altitude.

Although the use of the landing lights provides helpduring the takeoff, they become ineffective after theairplane has climbed to an altitude where the lightbeam no longer extends to the surface. The light cancause distortion when it is reflected by haze, smoke, orfog that might exist in the climb. Therefore, when thelanding light is used for the takeoff, it may be turnedoff after the climb is well established provided othertraffic in the area does not require its use for collisionavoidance.

ORIENTATION AND NAVIGATIONGenerally, at night it is difficult to see clouds andrestrictions to visibility, particularly on dark nights orunder overcast. The pilot flying under VFR must exer-cise caution to avoid flying into clouds or a layer offog. Usually, the first indication of flying into restrictedvisibility conditions is the gradual disappearance oflights on the ground. If the lights begin to take on anappearance of being surrounded by a halo or glow, thepilot should use caution in attempting further flight inthat same direction. Such a halo or glow around lightson the ground is indicative of ground fog. Rememberthat if a descent must be made through fog, smoke, orhaze in order to land, the horizontal visibility is consid-erably less when looking through the restriction than itis when looking straight down through it from above.Under no circumstances should a VFR night-flight bemade during poor or marginal weather conditionsunless both the pilot and aircraft are certificated andequipped for flight under instrument flight rules (IFR).

The pilot should practice and acquire competency instraight-and-level flight, climbs and descents, levelturns, climbing and descending turns, and steep turns.Recovery from unusual attitudes should also be prac-ticed, but only on dual flights with a flight instructor.The pilot should also practice these maneuvers with allthe cockpit lights turned OFF. This blackout training isnecessary if the pilot experiences an electrical orinstrument light failure. Training should also includeusing the navigation equipment and local NAVAIDs.

In spite of fewer references or checkpoints, night cross-country flights do not present particular problems if

preplanning is adequate, and the pilot continues tomonitor position, time estimates, and fuel consumed.NAVAIDs, if available, should be used to assist inmonitoring en route progress.

Crossing large bodies of water at night in single-engine airplanes could be potentially hazardous, notonly from the standpoint of landing (ditching) in thewater, but also because with little or no lighting thehorizon blends with the water, in which case, depthperception and orientation become difficult. Duringpoor visibility conditions over water, the horizon willbecome obscure, and may result in a loss of orienta-tion. Even on clear nights, the stars may be reflectedon the water surface, which could appear as a contin-uous array of lights, thus making the horizon difficultto identify.

Lighted runways, buildings, or other objects maycause illusions to the pilot when seen from differentaltitudes. At an altitude of 2,000 feet, a group of lightson an object may be seen individually, while at 5,000feet or higher, the same lights could appear to be onesolid light mass. These illusions may become quiteacute with altitude changes and if not overcome couldpresent problems in respect to approaches to lightedrunways.

APPROACHES AND LANDINGSWhen approaching the airport to enter the traffic pat-tern and land, it is important that the runway lightsand other airport lighting be identified as early aspossible. If the airport layout is unfamiliar to thepilot, sighting of the runway may be difficult untilvery close-in due to the maze of lights observed inthe area. [Figure 10-4] The pilot should fly towardthe rotating beacon until the lights outlining the run-way are distinguishable. To fly a traffic pattern ofproper size and direction, the runway threshold andrunway-edge lights must be positively identified.Once the airport lights are seen, these lights shouldbe kept in sight throughout the approach.

Figure 10-4. Use light patterns for orientation.

Ch 10.qxd 7/13/04 11:10 AM Page 10-6

Distance may be deceptiveat night due to limitedlighting conditions. A lackof intervening referenceson the ground and theinability of the pilot to com-pare the size and location ofdifferent ground objectscause this. This also appliesto the estimation of altitudeand speed. Consequently,more dependence must beplaced on flight instruments,particularly the altimeter andthe airspeed indicator.

When entering the trafficpattern, allow for plenty oftime to complete thebefore landing checklist. Ifthe heading indicator contains a heading bug, setting itto the runway heading will be an excellent referencefor the pattern legs.

Every effort should be made to maintain the recom-mended airspeeds and execute the approach andlanding in the same manner as during the day. A low,shallow approach is definitely inappropriate duringa night operation. The altimeter and VSI should beconstantly cross-checked against the airplane’s positionalong the base leg and final approach. A visualapproach slope indicator (VASI) is an indispensable aidin establishing and maintaining a proper glidepath.[Figure 10-5]

After turning onto the final approach and aligning theairplane midway between the two rows of runway-edgelights, the pilot should note and correct for any winddrift. Throughout the final approach, pitch and powershould be used to maintain a stabilized approach. Flapsshould be used the same as in a normal approach.Usually, halfway through the final approach, the land-ing light should be turned on. Earlier use of the landinglight may be necessary because of “Operation LightsON” or for local traffic considerations. The landinglight is sometimes ineffective since the light beam willusually not reach the ground from higher altitudes. Thelight may even be reflected back into the pilot’s eyesby any existing haze, smoke, or fog. This disadvantageis overshadowed by the safety considerations providedby using the “Operation Lights ON” procedure aroundother traffic.

The roundout and touchdown should be made in thesame manner as in day landings. At night, the judg-ment of height, speed, and sink rate is impaired by thescarcity of observable objects in the landing area. Theinexperienced pilot may have a tendency to round outtoo high until attaining familiarity with the proper

height for the correct roundout. To aid in determiningthe proper roundout point, continue a constantapproach descent until the landing lights reflect on therunway and tire marks on the runway can be seenclearly. At this point the roundout should be startedsmoothly and the throttle gradually reduced to idleas the airplane is touching down. [Figure 10-6]During landings without the use of landing lights, theroundout may be started when the runway lights at the

If both light bars are white,you are too high.

If you see red over red, you are below the glidepath.

Above Glidepath Below Glidepath On Glidepath

If the far bar is red and the near bar is white, you are on the glidepath. The memory aid "red over white, you're all right," is helpful in recalling the correct sequence of lights.

Figure 10-5. VASI.

Figure 10-6. Roundout when tire marks are visible.

10-7

Ch 10.qxd 7/13/04 11:10 AM Page 10-7

10-8

far end of the runway first appear to be rising higherthan the nose of the airplane. This demands a smoothand very timely roundout, and requires that the pilotfeel for the runway surface using power and pitchchanges, as necessary, for the airplane to settle slowlyto the runway. Blackout landings should always beincluded in night pilot training as an emergencyprocedure.

NIGHT EMERGENCIESPerhaps the pilot’s greatest concern about flying a single-engine airplane at night is the possibility of a completeengine failure and the subsequent emergency landing.This is a legitimate concern, even though continuingflight into adverse weather and poor pilot judgmentaccount for most serious accidents.

If the engine fails at night, several important proceduresand considerations to keep in mind are:

• Maintain positive control of the airplane andestablish the best glide configuration and airspeed.Turn the airplane towards an airport or away fromcongested areas.

• Check to determine the cause of the enginemalfunction, such as the position of fuel selec-tors, magneto switch, or primer. If possible, thecause of the malfunction should be correctedimmediately and the engine restarted.

• Announce the emergency situation to Air TrafficControl (ATC) or UNICOM. If already in radiocontact with a facility, do not change frequen-cies, unless instructed to change.

• If the condition of the nearby terrain is known,turn towards an unlighted portion of the area.Plan an emergency approach to an unlightedportion.

• Consider an emergency landing area close topublic access if possible. This may facilitaterescue or help, if needed.

• Maintain orientation with the wind to avoid adownwind landing.

• Complete the before landing checklist, andcheck the landing lights for operation at altitudeand turn ON in sufficient time to illuminate theterrain or obstacles along the flightpath. Thelanding should be completed in the normal land-ing attitude at the slowest possible airspeed. Ifthe landing lights are unusable and outside visualreferences are not available, the airplane shouldbe held in level-landing attitude until the groundis contacted.

• After landing, turn off all switches and evacuatethe airplane as quickly as possible.

Ch 10.qxd 7/13/04 11:10 AM Page 10-8

11-1

HIGH PERFORMANCE AND COMPLEXAIRPLANESTransition to a complex airplane, or a high performanceairplane, can be demanding for most pilots without pre-vious experience. Increased performance and increasedcomplexity both require additional planning, judgment,and piloting skills. Transition to these types ofairplanes, therefore, should be accomplished in asystematic manner through a structured course oftraining administered by a qualified flight instructor.

A complex airplane is defined as an airplane equippedwith a retractable landing gear, wing flaps, and acontrollable-pitch propeller. For a seaplane to beconsidered complex, it is required to have wing flaps anda controllable-pitch propeller. A high performanceairplane is defined as an airplane with an engine of morethan 200 horsepower.

WING FLAPSAirplanes can be designed to fly fast or slow. Highspeed requires thin, moderately cambered airfoils witha small wing area, whereas the high lift needed for lowspeeds is obtained with thicker highly camberedairfoils with a larger wing area. [Figure 11-1] Many

attempts have been made to compromise thisconflicting requirement of high cruise and slowlanding speeds.

Since an airfoil cannot have two different cambers atthe same time, one of two things must be done. Eitherthe airfoil can be a compromise, or a cruise airfoil canbe combined with a device for increasing the camber ofthe airfoil for low-speed flight. One method for varyingan airfoil’s camber is the addition of trailing edge flaps.Engineers call these devices a high-lift system.

FUNCTION OF FLAPSFlaps work primarily by changing the camber of theairfoil since deflection adds aft camber. Flap deflectiondoes not increase the critical (stall) angle of attack, andin some cases flap deflection actually decreases thecritical angle of attack.

Deflection of trailing edge control surfaces, such as theaileron, alters both lift and drag. With ailerondeflection, there is asymmetrical lift (rolling moment)and drag (adverse yaw). Wing flaps differ in thatdeflection acts symmetrically on the airplane. There isno roll or yaw effect, and pitch changes depend on theairplane design.

Straight

Elliptical

Tapered

Sweptback

Delta

Figure 11-1. Airfoil types.

Ch 11.qxd 5/7/04 8:50 AM Page 11-1

11-2

Pitch behavior depends on flap type, wing position,and horizontal tail location. The increased camberfrom flap deflection produces lift primarily on the rearportion of the wing. This produces a nosedownpitching moment; however, the change in tail loadfrom the downwash deflected by the flaps over thehorizontal tail has a significant influence on thepitching moment. Consequently, pitch behaviordepends on the design features of the particular airplane.

Flap deflection of up to 15° primarily produces liftwith minimal drag. The tendency to balloon up withinitial flap deflection is because of lift increase, but thenosedown pitching moment tends to offset the balloon.Deflection beyond 15° produces a large increase indrag. Drag from flap deflection is parasite drag, andas such is proportional to the square of the speed. Also,deflection beyond 15° produces a significant noseuppitching moment in most high-wing airplanes becausethe resulting downwash increases the airflow over thehorizontal tail.

FLAP EFFECTIVENESSFlap effectiveness depends on a number of factors, butthe most noticeable are size and type. For the purposeof this chapter, trailing edge flaps are classified as fourbasic types: plain (hinge), split, slotted, and Fowler.[Figure 11-2]

The plain or hinge flap is a hinged section of the wing.The structure and function are comparable to the othercontrol surfaces—ailerons, rudder, and elevator. Thesplit flap is more complex. It is the lower or undersideportion of the wing; deflection of the flap leaves thetrailing edge of the wing undisturbed. It is, however,more effective than the hinge flap because of greaterlift and less pitching moment, but there is more drag.Split flaps are more useful for landing, but the partiallydeflected hinge flaps have the advantage in takeoff.The split flap has significant drag at small deflections,whereas the hinge flap does not because airflowremains “attached” to the flap.

The slotted flap has a gap between the wing and theleading edge of the flap. The slot allows highpressure airflow on the wing undersurface to energizethe lower pressure over the top, thereby delaying flowseparation. The slotted flap has greater lift than thehinge flap but less than the split flap; but, because ofa higher lift-drag ratio, it gives better takeoff andclimb performance. Small deflections of the slottedflap give a higher drag than the hinge flap but lessthan the split. This allows the slotted flap to be usedfor takeoff.

The Fowler flap deflects down and aft to increase thewing area. This flap can be multi-slotted making it themost complex of the trailing edge systems. This

system does, however, give the maximum liftcoefficient. Drag characteristics at small deflectionsare much like the slotted flap. Because of structuralcomplexity and difficulty in sealing the slots, Fowlerflaps are most commonly used on larger airplanes.

OPERATIONAL PROCEDURESIt would be impossible to discuss all the many airplanedesign and flap combinations. This emphasizes theimportance of the FAA-approved Airplane FlightManual and/or Pilot’s Operating Handbook(AFM/POH) for a given airplane. However, whilesome AFM/POHs are specific as to operational use offlaps, many are lacking. Hence, flap operation makespilot judgment of critical importance. In addition, flapoperation is used for landings and takeoffs, duringwhich the airplane is in close proximity to the groundwhere the margin for error is small.

Since the recommendations given in the AFM/POH arebased on the airplane and the flap design combination,

Plain Flap

Split Flap

Slotted Flap

Fowler Flap

Figure 11-2. Four basic types of flaps.

Ch 11.qxd 5/7/04 8:50 AM Page 11-2

11-3

the pilot must relate the manufacturer’s recommenda-tion to aerodynamic effects of flaps. This requires thatthe pilot have a basic background knowledge of flapaerodynamics and geometry. With this information, thepilot must make a decision as to the degree of flapdeflection and time of deflection based on runway andapproach conditions relative to the wind conditions.

The time of flap extension and degree of deflection arerelated. Large flap deflections at one single point in thelanding pattern produce large lift changes that requiresignificant pitch and power changes in order tomaintain airspeed and glide slope. Incrementaldeflection of flaps on downwind, base, and finalapproach allow smaller adjustment of pitch and powercompared to extension of full flaps all at one time. Thisprocedure facilitates a more stabilized approach.

A soft- or short-field landing requires minimal speed attouchdown. The flap deflection that results in minimalgroundspeed, therefore, should be used. If obstacleclearance is a factor, the flap deflection that results inthe steepest angle of approach should be used. Itshould be noted, however, that the flap setting thatgives the minimal speed at touchdown does notnecessarily give the steepest angle of approach;however, maximum flap extension gives the steepestangle of approach and minimum speed at touchdown.Maximum flap extension, particularly beyond 30 to35°, results in a large amount of drag. This requireshigher power settings than used with partial flaps.Because of the steep approach angle combined withpower to offset drag, the flare with full flaps becomescritical. The drag produces a high sink rate that mustbe controlled with power, yet failure to reduce powerat a rate so that the power is idle at touchdown allowsthe airplane to float down the runway. A reduction inpower too early results in a hard landing.

Crosswind component is another factor to beconsidered in the degree of flap extension. Thedeflected flap presents a surface area for the wind toact on. In a crosswind, the “flapped” wing on theupwind side is more affected than the downwindwing. This is, however, eliminated to a slight extentin the crabbed approach since the airplane is morenearly aligned with the wind. When using a wing lowapproach, however, the lowered wing partiallyblankets the upwind flap, but the dihedral of the wingcombined with the flap and wind make lateral controlmore difficult. Lateral control becomes more difficultas flap extension reaches maximum and thecrosswind becomes perpendicular to the runway.

Crosswind effects on the “flapped” wing become morepronounced as the airplane comes closer to the ground.The wing, flap, and ground form a “container” that isfilled with air by the crosswind. With the wind striking

the deflected flap and fuselage side and with the flaplocated behind the main gear, the upwind wing willtend to rise and the airplane will tend to turn into thewind. Proper control position, therefore, is essentialfor maintaining runway alignment. Also, it maybe necessary to retract the flaps upon positiveground contact.

The go-around is another factor to consider whenmaking a decision about degree of flap deflectionand about where in the landing pattern to extendflaps. Because of the nosedown pitching momentproduced with flap extension, trim is used to offsetthis pitching moment. Application of full power inthe go-around increases the airflow over the“flapped” wing. This produces additional liftcausing the nose to pitch up. The pitch-up tendencydoes not diminish completely with flap retractionbecause of the trim setting. Expedient retraction offlaps is desirable to eliminate drag, thereby allowingrapid increase in airspeed; however, flap retractionalso decreases lift so that the airplane sinks rapidly.

The degree of flap deflection combined with designconfiguration of the horizontal tail relative to thewing requires that the pilot carefully monitor pitchand airspeed, carefully control flap retraction tominimize altitude loss, and properly use the rudderfor coordination. Considering these factors, the pilotshould extend the same degree of deflection at thesame point in the landing pattern. This requires that aconsistent traffic pattern be used. Therefore, the pilotcan have a preplanned go-around sequence based onthe airplane’s position in the landing pattern.

There is no single formula to determine the degree offlap deflection to be used on landing, because alanding involves variables that are dependent on eachother. The AFM/POH for the particular airplane willcontain the manufacturer’s recommendations forsome landing situations. On the other hand,AFM/POH information on flap usage for takeoff ismore precise. The manufacturer’s requirements arebased on the climb performance produced by a givenflap design. Under no circumstances should a flapsetting given in the AFM/POH be exceededfor takeoff.

CONTROLLABLE-PITCH PROPELLERFixed-pitch propellers are designed for best efficiencyat one speed of rotation and forward speed. This typeof propeller will provide suitable performance ina narrow range of airspeeds; however, efficiencywould suffer considerably outside this range. Toprovide high propeller efficiency through a widerange of operation, the propeller blade anglemust be controllable. The most convenient

Ch 11.qxd 5/7/04 8:50 AM Page 11-3

11-4

way of controlling the propeller blade angle is bymeans of a constant-speed governing system.

CONSTANT-SPEED PROPELLERThe constant-speed propeller keeps the blade angleadjusted for maximum efficiency for most conditionsof flight. When an engine is running at constantspeed, the torque (power) exerted by the engine at thepropeller shaft must equal the opposing load providedby the resistance of the air. The r.p.m. is controlled byregulating the torque absorbed by the propeller—inother words by increasing or decreasing theresistance offered by the air to the propeller. In thecase of a fixed-pitch propeller, the torque absorbedby the propeller is a function of speed, or r.p.m. If thepower output of the engine is changed, the engine willaccelerate or decelerate until an r.p.m. is reached atwhich the power delivered is equal to the powerabsorbed. In the case of a constant-speed propeller,the power absorbed is independent of the r.p.m., forby varying the pitch of the blades, the air resistanceand hence the torque or load, can be changed withoutreference to propeller speed. This is accomplishedwith a constant-speed propeller by means of agovernor. The governor, in most cases, is geared tothe engine crankshaft and thus is sensitive to changesin engine r.p.m.

The pilot controls the engine r.p.m. indirectly by meansof a propeller control in the cockpit, which isconnected to the governor. For maximum takeoffpower, the propeller control is moved all the wayforward to the low pitch/high r.p.m. position, and thethrottle is moved forward to the maximum allowablemanifold pressure position. To reduce power for climbor cruise, manifold pressure is reduced to the desiredvalue with the throttle, and the engine r.p.m. is reducedby moving the propeller control back toward the highpitch/low r.p.m. position until the desired r.p.m. isobserved on the tachometer. Pulling back on thepropeller control causes the propeller blades to moveto a higher angle. Increasing the propeller blade angle(of attack) results in an increase in the resistance of theair. This puts a load on the engine so it slows down. Inother words, the resistance of the air at the higher bladeangle is greater than the torque, or power, delivered tothe propeller by the engine, so it slows down to a pointwhere the two forces are in balance.

When an airplane is nosed up into a climb from levelflight, the engine will tend to slow down. Since thegovernor is sensitive to small changes in engine r.p.m.,it will decrease the blade angle just enough to keep theengine speed from falling off. If the airplane is noseddown into a dive, the governor will increase the bladeangle enough to prevent the engine from overspeeding.This allows the engine to maintain a constant r.p.m.,and thus maintain the power output. Changes in

airspeed and power can be obtained by changingr.p.m. at a constant manifold pressure; by changingthe manifold pressure at a constant r.p.m.; or bychanging both r.p.m. and manifold pressure. Thusthe constant-speed propeller makes it possible toobtain an infinite number of power settings.

TAKEOFF, CLIMB, AND CRUISEDuring takeoff, when the forward motion of theairplane is at low speeds and when maximum powerand thrust are required, the constant-speed propellersets up a low propeller blade angle (pitch). The lowblade angle keeps the angle of attack, with respect tothe relative wind, small and efficient at the low speed.[Figure 11-3]

At the same time, it allows the propeller to “slice itthin” and handle a smaller mass of air per revolution.This light load allows the engine to turn at maximumr.p.m. and develop maximum power. Although themass of air per revolution is small, the number ofrevolutions per minute is high. Thrust is maximum atthe beginning of the takeoff and then decreases as theairplane gains speed and the airplane drag increases.Due to the high slipstream velocity during takeoff,the effective lift of the wing behind the propeller(s)is increased.

As the airspeed increases after lift-off, the load on theengine is lightened because of the small blade angle.The governor senses this and increases the blade angleslightly. Again, the higher blade angle, with the higherspeeds, keeps the angle of attack with respect to therelative wind small and efficient.

Angle of Attack

ChordLine

Plane ofPropellerRotation

Angle of Attack

Chord Line(Blade Face)

STATIONARY FORWARD MOTION

Plane of PropellerRotation

Forward Airspeed

RelativeWind

RelativeWind

Figure 11-3. Propeller blade angle.

Ch 11.qxd 5/7/04 8:50 AM Page 11-4

11-5

For climb after takeoff, the power output of the engineis reduced to climb power by decreasing the manifoldpressure and lowering r.p.m. by increasing the bladeangle. At the higher (climb) airspeed and the higherblade angle, the propeller is handling a greater mass ofair per second at a lower slipstream velocity. Thisreduction in power is offset by the increase in propellerefficiency. The angle of attack is again kept small bythe increase in the blade angle with an increasein airspeed.

At cruising altitude, when the airplane is in level flight,less power is required to produce a higher airspeedthan is used in climb. Consequently, engine power isagain reduced by lowering the manifold pressure andincreasing the blade angle (to decrease r.p.m.). Thehigher airspeed and higher blade angle enable thepropeller to handle a still greater mass of air persecond at still smaller slipstream velocity. At normalcruising speeds, propeller efficiency is at, or nearmaximum efficiency. Due to the increase in bladeangle and airspeed, the angle of attack is still smalland efficient.

BLADE ANGLE CONTROLOnce the pilot selects the r.p.m. settings for thepropeller, the propeller governor automatically adjuststhe blade angle to maintain the selected r.p.m. It doesthis by using oil pressure. Generally, the oil pressureused for pitch change comes directly from the enginelubricating system. When a governor is employed,engine oil is used and the oil pressure is usuallyboosted by a pump, which is integrated with thegovernor. The higher pressure provides a quicker bladeangle change. The r.p.m. at which the propeller is tooperate is adjusted in the governor head. The pilotchanges this setting by changing the position of thegovernor rack through the cockpit propeller control.

On some constant-speed propellers, changes in pitchare obtained by the use of an inherent centrifugaltwisting moment of the blades that tends to flatten theblades toward low pitch, and oil pressure applied to ahydraulic piston connected to the propeller bladeswhich moves them toward high pitch. Another type ofconstant-speed propeller uses counterweights attachedto the blade shanks in the hub. Governor oil pressure

and the blade twisting moment move the blades towardthe low pitch position, and centrifugal force acting onthe counterweights moves them (and the blades)toward the high pitch position. In the first case above,governor oil pressure moves the blades towards highpitch, and in the second case, governor oil pressure andthe blade twisting moment move the blades toward lowpitch. A loss of governor oil pressure, therefore, willaffect each differently.

GOVERNING RANGEThe blade angle range for constant-speed propellersvaries from about 11 1/2 to 40°. The higher the speedof the airplane, the greater the blade angle range.[Figure 11-4]

The range of possible blade angles is termed thepropeller’s governing range. The governing range isdefined by the limits of the propeller blade’s travelbetween high and low blade angle pitch stops. As longas the propeller blade angle is within the governingrange and not against either pitch stop, a constantengine r.p.m. will be maintained. However, once thepropeller blade reaches its pitch-stop limit, the enginer.p.m. will increase or decrease with changes inairspeed and propeller load similar to a fixed-pitchpropeller. For example, once a specific r.p.m. isselected, if the airspeed decreases enough, thepropeller blades will reduce pitch, in an attempt tomaintain the selected r.p.m., until they contact theirlow pitch stops. From that point, any furtherreduction in airspeed will cause the engine r.p.m.to decrease. Conversely, if the airspeed increases,the propeller blade angle will increase until thehigh pitch stop is reached. The engine r.p.m. willthen begin to increase.

CONSTANT-SPEEDPROPELLER OPERATIONThe engine is started with the propeller control in thelow pitch/high r.p.m. position. This position reducesthe load or drag of the propeller and the result is easierstarting and warm-up of the engine. During warm-up,the propeller blade changing mechanism should beoperated slowly and smoothly through a full cycle.This is done by moving the propeller control (with the

Fixed Gear

Retractable

Turbo Retractable

Turbine Retractable

Transport Retractable

Aircraft Type Design Speed(m.p.h.)

Blade AngleRange

PitchLow High

160

180

225/240

250/300

325

111/2°

15°

20°

30°

40°

101/2°

11°

14°

10°

10/15°

22°

26°

34°

40°

50/55°

Figure 11-4. Blade angle range (values are approximate).

Ch 11.qxd 5/7/04 8:50 AM Page 11-5

11-6

manifold pressure set to produce about 1,600 r.p.m.)to the high pitch/low r.p.m. position, allowing ther.p.m. to stabilize, and then moving the propellercontrol back to the low pitch takeoff position. Thisshould be done for two reasons: to determinewhether the system is operating correctly, and tocirculate fresh warm oil through the propellergovernor system. It should be remembered that theoil has been trapped in the propeller cylinder sincethe last time the engine was shut down. There is acertain amount of leakage from the propellercylinder, and the oil tends to congeal, especially ifthe outside air temperature is low. Consequently, ifthe propeller isn’t exercised before takeoff, there isa possibility that the engine may overspeedon takeoff.

An airplane equipped with a constant-speed propellerhas better takeoff performance than a similarly poweredairplane equipped with a fixed-pitch propeller. This isbecause with a constant-speed propeller, an airplane candevelop its maximum rated horsepower (red line on thetachometer) while motionless. An airplane with a fixed-pitch propeller, on the other hand, must accelerate downthe runway to increase airspeed and aerodynamicallyunload the propeller so that r.p.m. and horsepower cansteadily build up to their maximum. With a constant-speed propeller, the tachometer reading should come upto within 40 r.p.m. of the red line as soon as full power isapplied, and should remain there for the entire takeoff.

Excessive manifold pressure raises the cylindercompression pressure, resulting in high stresses withinthe engine. Excessive pressure also produces highengine temperatures. A combination of high manifoldpressure and low r.p.m. can induce damagingdetonation. In order to avoid these situations, thefollowing sequence should be followed when makingpower changes.

• When increasing power, increase the r.p.m. first,and then the manifold pressure.

• When decreasing power, decrease the manifoldpressure first, and then decrease the r.p.m.

It is a fallacy that (in non-turbocharged engines) themanifold pressure in inches of mercury (inches Hg)should never exceed r.p.m. in hundreds for cruisepower settings. The cruise power charts in theAFM/POH should be consulted when selecting cruisepower settings. Whatever the combinations of r.p.m.and manifold pressure listed in these charts—they havebeen flight tested and approved by the airframe andpowerplant engineers for the respective airframe andengine manufacturer. Therefore, if there are powersettings such as 2,100 r.p.m. and 24 inches manifoldpressure in the power chart, they are approved for use.

With a constant-speed propeller, a power descent canbe made without overspeeding the engine. The systemcompensates for the increased airspeed of the descentby increasing the propeller blade angles. If the descentis too rapid, or is being made from a high altitude, themaximum blade angle limit of the blades is notsufficient to hold the r.p.m. constant. When thisoccurs, the r.p.m. is responsive to any changein throttle setting.

Some pilots consider it advisable to set the propellercontrol for maximum r.p.m. during the approach tohave full horsepower available in case of emergency.If the governor is set for this higher r.p.m. early in theapproach when the blades have not yet reached theirminimum angle stops, the r.p.m. may increase tounsafe limits. However, if the propeller control is notreadjusted for the takeoff r.p.m. until the approach isalmost completed, the blades will be against, or verynear their minimum angle stops and there will be littleif any change in r.p.m. In case of emergency, boththrottle and propeller controls should be moved totakeoff positions.

Many pilots prefer to feel the airplane respondimmediately when they give short bursts of thethrottle during approach. By making the approachunder a little power and having the propeller controlset at or near cruising r.p.m., this result canbe obtained.

Although the governor responds quickly to any changein throttle setting, a sudden and large increase in thethrottle setting will cause a momentary overspeedingof the engine until the blades become adjusted toabsorb the increased power. If an emergencydemanding full power should arise during approach,the sudden advancing of the throttle will causemomentary overspeeding of the engine beyond ther.p.m. for which the governor is adjusted. Thistemporary increase in engine speed acts as anemergency power reserve.

Some important points to remember concerningconstant-speed propeller operation are:

• The red line on the tachometer not only indicatesmaximum allowable r.p.m.; it also indicatesthe r.p.m. required to obtain the engine’srated horsepower.

• A momentary propeller overspeed may occurwhen the throttle is advanced rapidly for takeoff.This is usually not serious if the rated r.p.m. isnot exceeded by 10 percent for more than3 seconds.

• The green arc on the tachometer indicates thenormal operating range. When developing

Ch 11.qxd 5/7/04 8:50 AM Page 11-6

11-7

power in this range, the engine drives the pro-peller. Below the green arc, however, it is usuallythe windmilling propeller that powers theengine. Prolonged operation below the green arccan be detrimental to the engine.

• On takeoffs from low elevation airports, themanifold pressure in inches of mercury mayexceed the r.p.m. This is normal in most cases.The pilot should consult the AFM/POHfor limitations.

• All power changes should be made smoothlyand slowly to avoid overboosting and/oroverspeeding.

TURBOCHARGINGThe turbocharged engine allows the pilot to maintainsufficient cruise power at high altitudes where there isless drag, which means faster true airspeeds andincreased range with fuel economy. At the same time,the powerplant has flexibility and can be flown at a lowaltitude without the increased fuel consumption of aturbine engine. When attached to the standardpowerplant, the turbocharger does not take anyhorsepower from the powerplant to operate; it isrelatively simple mechanically, and some models canpressurize the cabin as well.

The turbocharger is an exhaust-driven device, whichraises the pressure and density of the induction airdelivered to the engine. It consists of two separatecomponents: a compressor and a turbine connected bya common shaft. The compressor supplies pressurizedair to the engine for high altitude operation. Thecompressor and its housing are between the ambientair intake and the induction air manifold. The turbineand its housing are part of the exhaust system andutilize the flow of exhaust gases to drive thecompressor. [Figure 11-5]

The turbine has the capability of producing manifoldpressure in excess of the maximum allowable for theparticular engine. In order not to exceed the maximumallowable manifold pressure, a bypass or waste gate isused so that some of the exhaust will be divertedoverboard before it passes through the turbine.

The position of the waste gate regulates the output ofthe turbine and therefore, the compressed air availableto the engine. When the waste gate is closed, all of theexhaust gases pass through and drive the turbine. Asthe waste gate opens, some of the exhaust gases arerouted around the turbine, through the exhaust bypassand overboard through the exhaust pipe.

The waste gate actuator is a spring-loaded piston,operated by engine oil pressure. The actuator, whichadjusts the waste gate position, is connected to thewaste gate by a mechanical linkage.

The control center of the turbocharger system isthe pressure controller. This device simplifiesturbocharging to one control: the throttle. Once thepilot has set the desired manifold pressure, virtually nothrottle adjustment is required with changes in altitude.The controller senses compressor dischargerequirements for various altitudes and controls the oilpressure to the waste gate actuator which adjusts thewaste gate accordingly. Thus the turbochargermaintains only the manifold pressure called for by thethrottle setting.

GROUND BOOSTING VS. ALTITUDETURBOCHARGINGAltitude turbocharging (sometimes called “normal-izing”) is accomplished by using a turbocharger thatwill maintain maximum allowable sea level manifoldpressure (normally 29 – 30 inches Hg) up to a certainaltitude. This altitude is specified by the airplanemanufacturer and is referred to as the airplane’scritical altitude. Above the critical altitude,

EXHAUST GASDISCHARGE

WASTE GATEThis controls the amount of exhaust through the turbine. Waste gate position is actuated by engine oil pressure.

TURBOCHARGERThe turbocharger incorporates a turbine, which is driven by exhaust gases, and a compressor that pressurizes the incoming air.

THROTTLE BODYThis regulates airflow to the engine.

INTAKE MANIFOLDPressurized air from the turbocharger is supplied to the cylinders.

EXHAUST MANIFOLDExhaust gas is ducted through the exhaust manifold and is used to turn the turbine which drives the compressor.

AIR INTAKEIntake air is ducted to the turbocharger where it is compressed.

Figure 11-5.Turbocharging system.

Ch 11.qxd 5/7/04 8:50 AM Page 11-7

11-8

the manifold pressure decreases as additional altitudeis gained. Ground boosting, on the other hand, is anapplication of turbocharging where more than thestandard 29 inches of manifold pressure is used inflight. In various airplanes using ground boosting,takeoff manifold pressures may go as high as 45inches of mercury.

Although a sea level power setting and maximumr.p.m. can be maintained up to the critical altitude,this does not mean that the engine is developing sealevel power. Engine power is not determined just bymanifold pressure and r.p.m. Induction airtemperature is also a factor. Turbocharged inductionair is heated by compression. This temperature risedecreases induction air density which causes apower loss. Maintaining the equivalent horsepoweroutput will require a somewhat higher manifoldpressure at a given altitude than if the induction airwere not compressed by turbocharging. If, on theother hand, the system incorporates an automaticdensity controller which, instead of maintaining aconstant manifold pressure, automatically positionsthe waste gate so as to maintain constant air densityto the engine, a near constant horsepower outputwill result.

OPERATING CHARACTERISTICSFirst and foremost, all movements of the powercontrols on turbocharged engines should be slow andgentle. Aggressive and/or abrupt throttle movementsincrease the possibility of overboosting. The pilotshould carefully monitor engine indications whenmaking power changes.

When the waste gate is open, the turbocharged enginewill react the same as a normally aspirated enginewhen the r.p.m. is varied. That is, when the r.p.m. isincreased, the manifold pressure will decrease slightly.When the engine r.p.m. is decreased, the manifoldpressure will increase slightly. However, when thewaste gate is closed, manifold pressure variation withengine r.p.m. is just the opposite of the normallyaspirated engine. An increase in engine r.p.m. willresult in an increase in manifold pressure, and adecrease in engine r.p.m. will result in a decrease inmanifold pressure.

Above the critical altitude, where the waste gateis closed, any change in airspeed will result in acorresponding change in manifold pressure. This istrue because the increase in ram air pressure with anincrease in airspeed is magnified by the compressorresulting in an increase in manifold pressure. Theincrease in manifold pressure creates a higher massflow through the engine, causing higher turbine speedsand thus further increasing manifold pressure.

When running at high altitudes, aviation gasoline maytend to vaporize prior to reaching the cylinder. If thisoccurs in the portion of the fuel system between thefuel tank and the engine-driven fuel pump, anauxiliary positive pressure pump may be needed in thetank. Since engine-driven pumps pull fuel, they areeasily vapor locked. A boost pump provides positivepressure—pushes the fuel—reducing the tendency tovaporize.

HEAT MANAGEMENTTurbocharged engines must be thoughtfully andcarefully operated, with continuous monitoring ofpressures and temperatures. There are two tempera-tures that are especially important—turbine inlettemperature (TIT) or in some installations exhaust gastemperature (EGT), and cylinder head temperature.TIT or EGT limits are set to protect the elements in thehot section of the turbocharger, while cylinder headtemperature limits protect the engine’s internal parts.

Due to the heat of compression of the induction air, aturbocharged engine runs at higher operatingtemperatures than a non-turbocharged engine. Becauseturbocharged engines operate at high altitudes, theirenvironment is less efficient for cooling. At altitudethe air is less dense and therefore, cools lessefficiently. Also, the less dense air causes thecompressor to work harder. Compressor turbinespeeds can reach 80,000 – 100,000 r.p.m., addingto the overall engine operating temperatures.Turbocharged engines are also operated at higherpower settings a greater portion of the time.

High heat is detrimental to piston engine operation. Itscumulative effects can lead to piston, ring, andcylinder head failure, and place thermal stress on otheroperating components. Excessive cylinder headtemperature can lead to detonation, which in turn cancause catastrophic engine failure. Turbochargedengines are especially heat sensitive. The key toturbocharger operation, therefore, is effective heatmanagement.

The pilot monitors the condition of a turbochargedengine with manifold pressure gauge, tachometer,exhaust gas temperature/turbine inlet temperaturegauge, and cylinder head temperature. The pilotmanages the “heat system” with the throttle, propellerr.p.m., mixture, and cowl flaps. At any given cruisepower, the mixture is the most influential control overthe exhaust gas/turbine inlet temperature. The throttleregulates total fuel flow, but the mixture governs thefuel to air ratio. The mixture, therefore, controlstemperature.

Exceeding temperature limits in an after takeoff climbis usually not a problem since a full rich mixture cools

Ch 11.qxd 5/7/04 8:50 AM Page 11-8

11-9

with excess fuel. At cruise, however, the pilot normallyreduces power to 75 percent or less and simultaneouslyadjusts the mixture. Under cruise conditions,temperature limits should be monitored most closelybecause it’s there that the temperatures are most likelyto reach the maximum, even though the engine isproducing less power. Overheating in an enrouteclimb, however, may require fully open cowl flaps anda higher airspeed.

Since turbocharged engines operate hotter at altitudethan do normally aspirated engines, they are moreprone to damage from cooling stress. Gradualreductions in power, and careful monitoring oftemperatures are essential in the descent phase. Thepilot may find it helpful to lower the landing gear togive the engine something to work against while poweris reduced and provide time for a slow cool down. Itmay also be necessary to lean the mixture slightly toeliminate roughness at the lower power settings.

TURBOCHARGER FAILUREBecause of the high temperatures and pressuresproduced in the turbine exhaust systems, anymalfunction of the turbocharger must be treated withextreme caution. In all cases of turbocharger operation,the manufacturer’s recommended procedures shouldbe followed. This is especially so in the case ofturbocharger malfunction. However, in those instanceswhere the manufacturer’s procedures do notadequately describe the actions to be taken in the eventof a turbocharger failure, the following proceduresshould be used.

OVERBOOST CONDITIONIf an excessive rise in manifold pressure occurs duringnormal advancement of the throttle (possibly owing tofaulty operation of the waste gate):

• Immediately retard the throttle smoothly to limitthe manifold pressure below the maximum forthe r.p.m. and mixture setting.

• Operate the engine in such a manner as to avoid afurther overboost condition.

LOW MANIFOLD PRESSUREAlthough this condition may be caused by a minorfault, it is quite possible that a serious exhaust leak hasoccurred creating a potentially hazardous situation:

• Shut down the engine in accordance with therecommended engine failure procedures, unlessa greater emergency exists that warrants contin-ued engine operation.

• If continuing to operate the engine, use the low-est power setting demanded by the situation andland as soon as practicable.

It is very important to ensure that correctivemaintenance is undertaken following anyturbocharger malfunction.

RETRACTABLE LANDING GEARThe primary benefits of being able to retract thelanding gear are increased climb performance andhigher cruise airspeeds due to the resulting decrease indrag. Retractable landing gear systems may beoperated either hydraulically or electrically, or mayemploy a combination of the two systems. Warningindicators are provided in the cockpit to show the pilotwhen the wheels are down and locked and when theyare up and locked or if they are in intermediatepositions. Systems for emergency operation are alsoprovided. The complexity of the retractable landinggear system requires that specific operating proceduresbe adhered to and that certain operating limitations notbe exceeded.

LANDING GEAR SYSTEMSAn electrical landing gear retraction system utilizes anelectrically driven motor for gear operation. Thesystem is basically an electrically driven jack forraising and lowering the gear. When a switch in thecockpit is moved to the UP position, the electric motoroperates. Through a system of shafts, gears, adapters,an actuator screw, and a torque tube, a force istransmitted to the drag strut linkages. Thus, the gearretracts and locks. Struts are also activated that openand close the gear doors. If the switch is moved to theDOWN position, the motor reverses and the gearmoves down and locks. Once activated the gear motorwill continue to operate until an up or down limitswitch on the motor’s gearbox is tripped.

A hydraulic landing gear retraction system utilizespressurized hydraulic fluid to actuate linkages to raiseand lower the gear. When a switch in the cockpit ismoved to the UP position, hydraulic fluid is directedinto the gear up line. The fluid flows throughsequenced valves and downlocks to the gearactuating cylinders. A similar process occurs duringgear extension. The pump which pressurizes the fluidin the system can be either engine driven orelectrically powered. If an electrically powered pumpis used to pressurize the fluid, the system is referredto as an electrohydraulic system. The system alsoincorporates a hydraulic reservoir to contain excessfluid, and to provide a means of determining systemfluid level.

Regardless of its power source, the hydraulic pump isdesigned to operate within a specific range. When asensor detects excessive pressure, a relief valve withinthe pump opens, and hydraulic pressure is routed backto the reservoir. Another type of relief valve preventsexcessive pressure that may result from thermal expan-sion. Hydraulic pressure is also regulated by limit

Ch 11.qxd 5/7/04 8:50 AM Page 11-9

11-10

switches. Each gear has two limit switches—onededicated to extension and one dedicated to retraction.These switches de-energize the hydraulic pump afterthe landing gear has completed its gear cycle. In theevent of limit switch failure, a backup pressure reliefvalve activates to relieve excess system pressure.

CONTROLS AND POSITION INDICATORSLanding gear position is controlled by a switch in thecockpit. In most airplanes, the gear switch is shapedlike a wheel in order to facilitate positive identificationand to differentiate it from other cockpit controls.[Figure 11-6]

Landing gear position indicators vary with differentmake and model airplanes. The most common types oflanding gear position indicators utilize a group oflights. One type consists of a group of three greenlights, which illuminate when the landing gear is downand locked. [Figure 11-6] Another type consists of onegreen light to indicate when the landing gear is downand an amber light to indicate when the gear is up. Stillother systems incorporate a red or amber light toindicate when the gear is in transit or unsafe forlanding. [Figure 11-7] The lights are usually of the“press to test” type, and the bulbs are interchangeable.[Figure 11-6]

Other types of landing gear position indicators consistof tab-type indicators with markings “UP” to indicatethe gear is up and locked, a display of red and whitediagonal stripes to show when the gear is unlocked, ora silhouette of each gear to indicate when it locks inthe DOWN position.

LANDING GEAR SAFETY DEVICESMost airplanes with a retractable landing gear have agear warning horn that will sound when the airplane isconfigured for landing and the landing gear is notdown and locked. Normally, the horn is linked to thethrottle or flap position, and/or the airspeed indicatorso that when the airplane is below a certain airspeed,

configuration, or power setting with the gear retracted,the warning horn will sound.

Accidental retraction of a landing gear may beprevented by such devices as mechanical downlocks,safety switches, and ground locks. Mechanicaldownlocks are built-in components of a gear retractionsystem and are operated automatically by the gearretraction system. To prevent accidental operation ofthe downlocks, and inadvertent landing gear retractionwhile the airplane is on the ground, electricallyoperated safety switches are installed.

A landing gear safety switch, sometimes referred to asa squat switch, is usually mounted in a bracket on oneof the main gear shock struts. [Figure 11-8] When thestrut is compressed by the weight of the airplane, theswitch opens the electrical circuit to the motor ormechanism that powers retraction. In this way, if thelanding gear switch in the cockpit is placed in theRETRACT position when weight is on the gear, thegear will remain extended, and the warning horn maysound as an alert to the unsafe condition. Once theweight is off the gear, however, such as on takeoff, thesafety switch will release and the gear will retract.

Many airplanes are equipped with additional safetydevices to prevent collapse of the gear when theairplane is on the ground. These devices are calledground locks. One common type is a pin installed inaligned holes drilled in two or more units of thelanding gear support structure. Another type is aspring-loaded clip designed to fit around and hold twoor more units of the support structure together. Alltypes of ground locks usually have red streamerspermanently attached to them to readily indicatewhether or not they are installed.

EMERGENCY GEAR EXTENSION SYSTEMSThe emergency extension system lowers the landinggear if the main power system fails. Some airplanes

Figure 11-6. Typical landing gear switches and positionindicators.

Figure 11-7. Typical landing gear switches and positionindicators.

Ch 11.qxd 5/7/04 8:50 AM Page 11-10

11-11

have an emergency release handle in the cockpit,which is connected through a mechanical linkage tothe gear uplocks. When the handle is operated, it

releases the uplocks and allows the gears to free fall, orextend under their own weight. [Figure 11-9]

Safety Switch

Landing GearSelector Valve

Lock ReleaseSolenoid

Lock-Pin

28V DCBus Bar

Figure 11-8. Landing gear safety switch.

Hand Pump Compressed Gas

Hand Crank

Figure 11-9.Typical emergency gear extension systems.

Ch 11.qxd 5/7/04 8:50 AM Page 11-11

11-12

should then turn on the battery master switch andensure that the landing gear position indicators showthat the gear is down and locked.

External inspection of the landing gear shouldconsist of checking individual system components.[Figure 11-10] The landing gear, wheel well, andadjacent areas should be clean and free of mud anddebris. Dirty switches and valves may cause falsesafe light indications or interrupt the extension cyclebefore the landing gear is completely down andlocked. The wheel wells should be clear of anyobstructions, as foreign objects may damage the gearor interfere with its operation. Bent gear doors may

Figure 11-10. Retractable landing gear inspectioncheckpoints.

On other airplanes, release of the uplock isaccomplished using compressed gas, which is directedto uplock release cylinders.

In some airplanes, design configurations makeemergency extension of the landing gear by gravityand air loads alone impossible or impractical. In theseairplanes, provisions are included for forceful gearextension in an emergency. Some installations aredesigned so that either hydraulic fluid or compressedgas provides the necessary pressure, while others use amanual system such as a hand crank for emergencygear extension. [Figure 11-9] Hydraulic pressure foremergency operation of the landing gear may beprovided by an auxiliary hand pump, an accumulator,or an electrically powered hydraulic pump dependingon the design of the airplane.

OPERATIONAL PROCEDURESPREFLIGHTBecause of their complexity, retractable landing gearsdemand a close inspection prior to every flight. Theinspection should begin inside the cockpit. The pilotshould first make certain that the landing gear selectorswitch is in the GEAR DOWN position. The pilot

Ch 11.qxd 5/7/04 8:50 AM Page 11-12

11-13

be an indication of possible problems with normalgear operation.

Shock struts should be properly inflated and thepistons clean. Main gear and nose gear uplock anddownlock mechanisms should be checked for generalcondition. Power sources and retracting mechanismsshould be checked for general condition, obviousdefects, and security of attachment. Hydraulic linesshould be checked for signs of chafing, and leakageat attach points. Warning system micro switches(squat switches) should be checked for cleanlinessand security of attachment. Actuating cylinders,sprockets, universals, drive gears, linkages and anyother accessible components should be checked forcondition and obvious defects. The airplane structureto which the landing gear is attached should bechecked for distortion, cracks, and general condition.All bolts and rivets should be intact and secure.

TAKEOFF AND CLIMBNormally, the landing gear should be retracted afterlift-off when the airplane has reached an altitudewhere, in the event of an engine failure or otheremergency requiring an aborted takeoff, the airplanecould no longer be landed on the runway. This proce-dure, however, may not apply to all situations. Landinggear retraction should be preplanned, taking intoaccount the length of the runway, climb gradient,obstacle clearance requirements, the characteristics ofthe terrain beyond the departure end of the runway, andthe climb characteristics of the particular airplane. Forexample, in some situations it may be preferable, in theevent of an engine failure, to make an off airport forcedlanding with the gear extended in order to takeadvantage of the energy absorbing qualities of terrain(see Chapter 16). In which case, a delay in retractingthe landing gear after takeoff from a short runway maybe warranted. In other situations, obstacles in the climbpath may warrant a timely gear retraction after takeoff.Also, in some airplanes the initial climb pitch attitudeis such that any view of the runway remaining isblocked, making an assessment of the feasibility oftouching down on the remaining runway difficult.

Premature landing gear retraction should be avoided.The landing gear should not be retracted until apositive rate of climb is indicated on the flightinstruments. If the airplane has not attained a positiverate of climb, there is always the chance it may settleback onto the runway with the gear retracted. This isespecially so in cases of premature lift-off. The pilotshould also remember that leaning forward to reach thelanding gear selector may result in inadvertent forwardpressure on the yoke, which will cause the airplane todescend.

As the landing gear retracts, airspeed will increase andthe airplane’s pitch attitude may change. The gear may

take several seconds to retract. Gear retraction andlocking (and gear extension and locking) isaccompanied by sound and feel that are unique to thespecific make and model airplane. The pilot shouldbecome familiar with the sounds and feel of normalgear retraction so that any abnormal gear operation canbe readily discernable. Abnormal landing gearretraction is most often a clear sign that the gearextension cycle will also be abnormal.

APPROACH AND LANDING The operating loads placed on the landing gear athigher airspeeds may cause structural damage due tothe forces of the airstream. Limiting speeds, therefore,are established for gear operation to protect the gearcomponents from becoming overstressed during flight.These speeds are not found on the airspeed indicator.They are published in the AFM/POH for the particularairplane and are usually listed on placards in thecockpit. [Figure 11-11] The maximum landingextended speed (VLE ) is the maximum speed at whichthe airplane can be flown with the landing gearextended. The maximum landing gear operating speed(VLO) is the maximum speed at which the landing gearmay be operated through its cycle.

The landing gear is extended by placing the gearselector switch in the GEAR DOWN position. As thelanding gear extends, the airspeed will decrease andthe pitch attitude may increase. During the severalseconds it takes for the gear to extend, the pilotshould be attentive to any abnormal sounds or feel.The pilot should confirm that the landing gear hasextended and locked by the normal sound and feel ofthe system operation as well as by the gear positionindicators in the cockpit. Unless the landing gear hasbeen previously extended to aid in a descent to trafficpattern altitude, the landing gear should be extendedby the time the airplane reaches a point on the down-wind leg that is opposite the point of intendedlanding. The pilot should establish a standardprocedure consisting of a specific position on thedownwind leg at which to lower the landing gear.Strict adherence to this procedure will aid the pilot inavoiding unintentional gear up landings.

Figure 11-11. Placarded gear speeds in the cockpit.

Ch 11.qxd 5/7/04 8:50 AM Page 11-13

11-14

Operation of an airplane equipped with a retractablelanding gear requires the deliberate, careful, andcontinued use of an appropriate checklist. When onthe downwind leg, the pilot should make it a habit tocomplete the landing gear checklist for that airplane.This accomplishes two purposes. It ensures thataction has been taken to lower the gear, and itincreases the pilot’s awareness so that the gear downindicators can be rechecked prior to landing.

Unless good operating practices dictate otherwise, thelanding roll should be completed and the airplaneclear of the runway before any levers or switches areoperated. This will accomplish the following: Thelanding gear strut safety switches will be actuated,deactivating the landing gear retract system. Afterrollout and clearing the runway, the pilot will be ableto focus attention on the after landing checklist and toidentify the proper controls.

Pilots transitioning to retractable gear airplanes shouldbe aware that the most common pilot operationalfactors involved in retractable gear airplane accidentsare:

• Neglected to extend landing gear.

• Inadvertently retracted landing gear.

• Activated gear, but failed to check gear position.

• Misused emergency gear system.

• Retracted gear prematurely on takeoff.

• Extended gear too late.

In order to minimize the chances of a landing gearrelated mishap, the pilot should:

• Use an appropriate checklist. (A condensedchecklist mounted in view of the pilot as areminder for its use and easy reference can beespecially helpful.)

• Be familiar with, and periodically review, thelanding gear emergency extension procedures forthe particular airplane.

• Be familiar with the landing gear warning hornand warning light systems for the particularairplane. Use the horn system to cross-check thewarning light system when an unsafe conditionis noted.

• Review the procedure for replacing light bulbsin the landing gear warning light displays for theparticular airplane, so that you can properlyreplace a bulb to determine if the bulb(s) in thedisplay is good. Check to see if spare bulbs areavailable in the airplane spare bulb supply as partof the preflight inspection.

• Be familiar with and aware of the sounds andfeel of a properly operating landing gear system.

TRANSITION TRAININGTransition to a complex airplane or a highperformance airplane should be accomplished througha structured course of training administered by acompetent and qualified flight instructor. The trainingshould be accomplished in accordance with a groundand flight training syllabus. [Figure 11-12]

This sample syllabus for transition training is to beconsidered flexible. The arrangement of the subjectmatter may be changed and the emphasis may beshifted to fit the qualifications of the transitioningpilot, the airplane involved, and the circumstances ofthe training situation, provided the prescribedproficiency standards are achieved. These standardsare contained in the practical test standardsappropriate for the certificate that the transitioningpilot holds or is working towards.

The training times indicated in the syllabus are basedon the capabilities of a pilot who is currently activeand fully meets the present requirements for theissuance of at least a private pilot certificate. The timeperiods may be reduced for pilots with higherqualifications or increased for pilots who do not meetthe current certification requirements or who have hadlittle recent flight experience.

Ch 11.qxd 5/7/04 8:50 AM Page 11-14

11-15

1. Operations sections of flight manual2. Line inspection3. Cockpit familiarization

1. Flight training maneuvers2. Takeoffs, landings and go-arounds

1. Aircraft loading, limitations and servicing2. Instruments, radio and special equipment3. Aircraft systems

1. Emergency operations2. Control by reference to instruments3. Use of radio and autopilot

As assigned by flight instructor

1. Performance section of flight manual2. Cruise control3. Review

1. Short and soft-field takeoffs and landings2. Maximum performance operations

As assigned by flight instructor

Ground Instruction Flight Instruction Directed Practice*

1 Hour—CHECKOUT

1 Hour 1 Hour

1 Hour 1 Hour 1 Hour

1 Hour 1 Hour 1 Hour

* The directed practice indicated may be conducted solo or with a safety pilot at the discretion of the instructor.

Figure 11-12.Transition training syllabus.

Ch 11.qxd 5/7/04 8:50 AM Page 11-15

11-16

Ch 11.qxd 5/7/04 8:50 AM Page 11-16

MULTIENGINE FLIGHTThis chapter is devoted to the factors associated withthe operation of small multiengine airplanes. For thepurpose of this handbook, a “small” multiengine air-plane is a reciprocating or turbopropeller-poweredairplane with a maximum certificated takeoff weightof 12,500 pounds or less. This discussion assumes aconventional design with two engines—one mountedon each wing. Reciprocating engines are assumedunless otherwise noted. The term “light-twin,”although not formally defined in the regulations, isused herein as a small multiengine airplane with amaximum certificated takeoff weight of 6,000 poundsor less.

There are several unique characteristics of multiengineairplanes that make them worthy of a separate class rat-ing. Knowledge of these factors and proficient flightskills are a key to safe flight in these airplanes. Thischapter deals extensively with the numerous aspects ofone engine inoperative (OEI) flight. However, pilotsare strongly cautioned not to place undue emphasison mastery of OEI flight as the sole key to flyingmultiengine airplanes safely. The inoperative engineinformation that follows is extensive only becausethis chapter emphasizes the differences between flyingmultiengine airplanes as contrasted to single-engineairplanes.

The modern, well-equipped multiengine airplane canbe remarkably capable under many circumstances. But,as with single-engine airplanes, it must be flown pru-dently by a current and competent pilot to achieve thehighest possible level of safety.

This chapter contains information and guidance on theperformance of certain maneuvers and procedures insmall multiengine airplanes for the purposes of flighttraining and pilot certification testing. The finalauthority on the operation of a particular make andmodel airplane, however, is the airplane manufacturer.Both the flight instructor and the student should beaware that if any of the guidance in this handbook con-flicts with the airplane manufacturer’s recommendedprocedures and guidance as contained in the FAA-approved Airplane Flight Manual and/or Pilot’sOperating Handbook (AFM/POH), it is the airplanemanufacturer’s guidance and procedures that takeprecedence.

GENERALThe basic difference between operating a multiengineairplane and a single-engine airplane is the potentialproblem involving an engine failure. The penalties forloss of an engine are twofold: performance and control.The most obvious problem is the loss of 50 percentof power, which reduces climb performance 80 to 90percent, sometimes even more. The other is the con-trol problem caused by the remaining thrust, whichis now asymmetrical. Attention to both these factorsis crucial to safe OEI flight. The performance andsystems redundancy of a multiengine airplane is asafety advantage only to a trained and proficientpilot.

TERMS AND DEFINITIONSPilots of single-engine airplanes are already familiarwith many performance “V” speeds and their defini-tions. Twin-engine airplanes have several additionalV speeds unique to OEI operation. These speeds aredifferentiated by the notation “SE”, for single engine.A review of some key V speeds and several new Vspeeds unique to twin-engine airplanes follows.

• VR – Rotation speed. The speed at which backpressure is applied to rotate the airplane to a take-off attitude.

• VLOF – Lift-off speed. The speed at which theairplane leaves the surface. (Note: some manu-facturers reference takeoff performance data toVR, others to VLOF.)

• VX – Best angle of climb speed. The speed atwhich the airplane will gain the greatest altitudefor a given distance of forward travel.

• VXSE – Best angle-of-climb speed with oneengine inoperative.

• VY – Best rate of climb speed. The speed atwhich the airplane will gain the most altitude fora given unit of time.

• VYSE – Best rate-of-climb speed with one engineinoperative. Marked with a blue radial line onmost airspeed indicators. Above the single-engineabsolute ceiling, VYSE yields the minimum rate ofsink.

• VSSE – Safe, intentional one-engine-inoperativespeed. Originally known as safe single-engine

12-1

Ch 12.qxd 5/7/04 9:54 AM Page 12-1

speed. Now formally defined in Title 14 of theCode of Federal Regulations (14 CFR) part 23,Airworthiness Standards, and required to beestablished and published in the AFM/POH. It isthe minimum speed to intentionally render thecritical engine inoperative.

• VMC – Minimum control speed with the criticalengine inoperative. Marked with a red radial lineon most airspeed indicators. The minimum speedat which directional control can be maintainedunder a very specific set of circumstances outlinedin 14 CFR part 23, Airworthiness Standards.Under the small airplane certification regulationscurrently in effect, the flight test pilot must be ableto (1) stop the turn that results when the criticalengine is suddenly made inoperative within 20°of the original heading, using maximum rudderdeflection and a maximum of 5° bank, and (2)thereafter, maintain straight flight with notmore than a 5° bank. There is no requirement inthis determination that the airplane be capableof climbing at this airspeed. VMC onlyaddresses directional control. Further discus-sion of VMC as determined during airplane cer-tification and demonstrated in pilot trainingfollows in minimum control airspeed (VMC)demonstration. [Figure 12-1]

Figure 12-1. Airspeed indicator markings for a multiengineairplane.

Unless otherwise noted, when V speeds are given inthe AFM/POH, they apply to sea level, standard dayconditions at maximum takeoff weight. Performancespeeds vary with aircraft weight, configuration, andatmospheric conditions. The speeds may be stated instatute miles per hour (m.p.h.) or knots (kts), and theymay be given as calibrated airspeeds (CAS) or indi-cated airspeeds (IAS). As a general rule, the newer

AFM/POHs show V speeds in knots indicated airspeed(KIAS). Some V speeds are also stated in knots cali-brated airspeed (KCAS) to meet certain regulatoryrequirements. Whenever available, pilots should oper-ate the airplane from published indicated airspeeds.

With regard to climb performance, the multiengineairplane, particularly in the takeoff or landing con-figuration, may be considered to be a single-engineairplane with its powerplant divided into two units.There is nothing in 14 CFR part 23 that requires amultiengine airplane to maintain altitude while inthe takeoff or landing configuration with one engineinoperative. In fact, many twins are not required todo this in any configuration, even at sea level.

The current 14 CFR part 23 single-engine climbperformance requirements for reciprocating engine-powered multiengine airplanes are as follows.

• More than 6,000 pounds maximum weightand/or VSO more than 61 knots: the single-engine rate of climb in feet per minute (f.p.m.) at5,000 feet MSL must be equal to at least .027VSO

2. For airplanes type certificated February 4,1991, or thereafter, the climb requirement isexpressed in terms of a climb gradient, 1.5 per-cent. The climb gradient is not a direct equiva-lent of the .027 VSO

2 formula. Do not confuse thedate of type certification with the airplane’smodel year. The type certification basis of manymultiengine airplanes dates back to CAR 3 (theCivil Aviation Regulations, forerunner of today’sCode of Federal Regulations).

• 6,000 pounds or less maximum weight and VSO61 knots or less: the single-engine rate of climbat 5,000 feet MSL must simply be determined.The rate of climb could be a negative number.There is no requirement for a single-enginepositive rate of climb at 5,000 feet or any otheraltitude. For light-twins type certificatedFebruary 4, 1991, or thereafter, the single-engine climb gradient (positive or negative) issimply determined.

Rate of climb is the altitude gain per unit of time, whileclimb gradient is the actual measure of altitude gainedper 100 feet of horizontal travel, expressed as a per-centage. An altitude gain of 1.5 feet per 100 feet oftravel (or 15 feet per 1,000, or 150 feet per 10,000) is aclimb gradient of 1.5 percent.

There is a dramatic performance loss associated withthe loss of an engine, particularly just after takeoff.Any airplane’s climb performance is a function ofthrust horsepower which is in excess of that required

12-2

Ch 12.qxd 5/7/04 9:54 AM Page 12-2

for level flight. In a hypothetical twin with each engineproducing 200 thrust horsepower, assume that the totallevel-flight thrust horsepower required is 175. In thissituation, the airplane would ordinarily have a reserveof 225 thrust horsepower available for climb. Loss ofone engine would leave only 25 (200 minus 175) thrusthorsepower available for climb, a drastic reduction.Sea level rate-of-climb performance losses of at least80 to 90 percent, even under ideal circumstances, aretypical for multiengine airplanes in OEI flight.

OPERATION OF SYSTEMSThis section will deal with systems that are generallyfound on multiengine airplanes. Multiengine airplanesshare many features with complex single-engine air-planes. There are certain systems and features coveredhere, however, that are generally unique to airplaneswith two or more engines.

PROPELLERSThe propellers of the multiengine airplane may out-wardly appear to be identical in operation to theconstant-speed propellers of many single-engineairplanes, but this is not the case. The propellers ofmultiengine airplanes are featherable, to minimizedrag in the event of an engine failure. Dependingupon single-engine performance, this feature oftenpermits continued flight to a suitable airport followingan engine failure. To feather a propeller is to stopengine rotation with the propeller blades streamlinedwith the airplane’s relative wind, thus to minimizedrag. [Figure 12-2]

Feathering is necessary because of the change in para-site drag with propeller blade angle. [Figure 12-3]When the propeller blade angle is in the featheredposition, the change in parasite drag is at a minimumand, in the case of a typical multiengine airplane, theadded parasite drag from a single feathered propelleris a relatively small contribution to the airplane totaldrag.

At the smaller blade angles near the flat pitch position,the drag added by the propeller is very large. At thesesmall blade angles, the propeller windmilling at highr.p.m. can create such a tremendous amount of drag thatthe airplane may be uncontrollable. The propeller wind-milling at high speed in the low range of blade anglescan produce an increase in parasite drag which may beas great as the parasite drag of the basic airplane.

As a review, the constant-speed propellers on almostall single-engine airplanes are of the non-feathering,oil-pressure-to-increase-pitch design. In this design,increased oil pressure from the propeller governordrives the blade angle towards high pitch, low r.p.m.

In contrast, the constant-speed propellers installedon most multiengine airplanes are full feathering,

counterweighted, oil-pressure-to-decrease-pitchdesigns. In this design, increased oil pressure from thepropeller governor drives the blade angle towards lowpitch, high r.p.m.—away from the feather blade angle.In effect, the only thing that keeps these propellersfrom feathering is a constant supply of high pressureengine oil. This is a necessity to enable propeller feath-ering in the event of a loss of oil pressure or a propellergovernor failure.

FullFeathered

90°HighPitch

LowPitch

Figure 12-2. Feathered propeller.

Change inEquivalentParasite

Drag

Propeller Blade Angle

0 15 30 45 60 90

PROPELLER DRAG CONTRIBUTION

WindmillingPropeller

StationaryPropeller Feathered

Position

Flat Blade Position

Figure 12-3. Propeller drag contribution.

12-3

Ch 12.qxd 5/7/04 9:54 AM Page 12-3

The aerodynamic forces alone acting upon a wind-milling propeller tend to drive the blades to low pitch,high r.p.m. Counterweights attached to the shank ofeach blade tend to drive the blades to high pitch, lowr.p.m. Inertia, or apparent force called centrifugal forceacting through the counterweights is generally slightlygreater than the aerodynamic forces. Oil pressure fromthe propeller governor is used to counteract the coun-terweights and drives the blade angles to low pitch,high r.p.m. A reduction in oil pressure causes the r.p.m.to be reduced from the influence of the counterweights.[Figure 12-4]

To feather the propeller, the propeller control isbrought fully aft. All oil pressure is dumped from thegovernor, and the counterweights drive the propellerblades towards feather. As centrifugal force acting onthe counterweights decays from decreasing r.p.m.,additional forces are needed to completely feather theblades. This additional force comes from either aspring or high pressure air stored in the propellerdome, which forces the blades into the feathered posi-tion. The entire process may take up to 10 seconds.

Feathering a propeller only alters blade angle and stopsengine rotation. To completely secure the engine, thepilot must still turn off the fuel (mixture, electric boostpump, and fuel selector), ignition, alternator/generator,and close the cowl flaps. If the airplane is pressurized,

there may also be an air bleed to close for the failedengine. Some airplanes are equipped with firewallshutoff valves that secure several of these systemswith a single switch.

Completely securing a failed engine may not be neces-sary or even desirable depending upon the failuremode, altitude, and time available. The position of thefuel controls, ignition, and alternator/generatorswitches of the failed engine has no effect on aircraftperformance. There is always the distinct possibilityof manipulating the incorrect switch under conditionsof haste or pressure.

To unfeather a propeller, the engine must be rotatedso that oil pressure can be generated to move thepropeller blades from the feathered position. Theignition is turned on prior to engine rotation with thethrottle at low idle and the mixture rich. With thepropeller control in a high r.p.m. position, the starteris engaged. The engine will begin to windmill, start,and run as oil pressure moves the blades out offeather. As the engine starts, the propeller r.p.m.should be immediately reduced until the engine hashad several minutes to warm up; the pilot shouldmonitor cylinder head and oil temperatures.

Should the r.p.m. obtained with the starter be insuffi-cient to unfeather the propeller, an increase in airspeed

CounterweightAction

Aerodynamic Force

Hydraulic Force

High-pressure oil enters the cylinder through the center of the propeller shaft and piston rod. The propeller control regulates the flow of high-pressure oil from a governor.

A hydraulic piston in the hub of the propeller is connected to each blade by a piston rod. This rod is attached to forks that slide over the pitch-change pin mounted in the root of each blade.

The oil pressure moves the piston toward the front of the cylinder, moving the piston rod and forks forward.

The forks push the pitch-change pin of each blade toward the front of the hub, causing the blades to twist toward the low-pitch position.

A nitrogen pressure charge or mechanical spring in the front of the hub opposes the oil pressure, and causes the propeller to move toward high-pitch.

Counterweights also cause the blades to move toward the high-pitch and feather positions. The counter-weights counteract the aerodynamic twisting force that tries to move the blades toward a low-pitch angle.

Nitrogen Pressure or SpringForce, and Counterweight Action

Figure 12-4. Pitch change forces.

12-4

Ch 12.qxd 5/7/04 9:54 AM Page 12-4

from a shallow dive will usually help. In any event, theAFM/POH procedures should be followed for theexact unfeathering procedure. Both feathering andstarting a feathered reciprocating engine on the groundare strongly discouraged by manufacturers due to theexcessive stress and vibrations generated.

As just described, a loss of oil pressure from the pro-peller governor allows the counterweights, springand/or dome charge to drive the blades to feather.Logically then, the propeller blades should featherevery time an engine is shut down as oil pressure fallsto zero. Yet, this does not occur. Preventing this is asmall pin in the pitch changing mechanism of thepropeller hub that will not allow the propeller bladesto feather once r.p.m. drops below approximately800. The pin senses a lack of centrifugal force frompropeller rotation and falls into place, preventing theblades from feathering. Therefore, if a propeller is tobe feathered, it must be done before engine r.p.m.decays below approximately 800. On one popularmodel of turboprop engine, the propeller blades do,in fact, feather with each shutdown. This propeller isnot equipped with such centrifugally-operated pins,due to a unique engine design.

An unfeathering accumulator is an optional device thatpermits starting a feathered engine in flight without theuse of the electric starter. An accumulator is any devicethat stores a reserve of high pressure. On multiengineairplanes, the unfeathering accumulator stores a smallreserve of engine oil under pressure from compressedair or nitrogen. To start a feathered engine in flight,the pilot moves the propeller control out of thefeather position to release the accumulator pressure.The oil flows under pressure to the propeller hub anddrives the blades toward the high r.p.m., low pitchposition, whereupon the propeller will usually beginto windmill. (On some airplanes, an assist from theelectric starter may be necessary to initiate rotationand completely unfeather the propeller.) If fuel andignition are present, the engine will start and run.For airplanes used in training, this saves much elec-tric starter and battery wear. High oil pressure fromthe propeller governor recharges the accumulatorjust moments after engine rotation begins.

PROPELLER SYNCHRONIZATIONMany multiengine airplanes have a propeller synchro-nizer (prop sync) installed to eliminate the annoying“drumming” or “beat” of propellers whose r.p.m. areclose, but not precisely the same. To use prop sync, thepropeller r.p.m. are coarsely matched by the pilot andthe system is engaged. The prop sync adjusts the r.p.m.of the “slave” engine to precisely match the r.p.m. ofthe “master” engine, and then maintains that relation-ship. The prop sync should be disengaged when thepilot selects a new propeller r.p.m., then re-engaged

after the new r.p.m. is set. The prop sync should alwaysbe off for takeoff, landing, and single-engine opera-tion. The AFM/POH should be consulted for systemdescription and limitations.

A variation on the propeller synchronizer is the pro-peller synchrophaser. Prop sychrophase acts muchlike a synchronizer to precisely match r.p.m., but thesynchrophaser goes one step further. It not onlymatches r.p.m. but actually compares and adjusts thepositions of the individual blades of the propellers intheir arcs. There can be significant propeller noise andvibration reductions with a propeller synchrophaser.From the pilot’s perspective, operation of a propellersynchronizer and a propeller syncrophaser are verysimilar. A synchrophaser is also commonly referred toas prop sync, although that is not entirely correctnomenclature from a technical standpoint.

As a pilot aid to manually synchronizing thepropellers, some twins have a small gauge mountedin or by the tachometer(s) with a propeller symbolon a disk that spins. The pilot manually fine tunesthe engine r.p.m. so as to stop disk rotation, therebysynchronizing the propellers. This is a useful backupto synchronizing engine r.p.m. using the audiblepropeller beat. This gauge is also found installedwith most propeller synchronizer and synchrophasesystems. Some synchrophase systems use a knob forthe pilot to control the phase angle.

FUEL CROSSFEEDFuel crossfeed systems are also unique to multiengineairplanes. Using crossfeed, an engine can draw fuelfrom a fuel tank located in the opposite wing.

On most multiengine airplanes, operation in the cross-feed mode is an emergency procedure used to extendairplane range and endurance in OEI flight. There area few models that permit crossfeed as a normal, fuelbalancing technique in normal operation, but these arenot common. The AFM/POH will describe crossfeedlimitations and procedures, which vary significantlyamong multiengine airplanes.

Checking crossfeed operation on the ground with aquick repositioning of the fuel selectors does nothingmore than ensure freedom of motion of the handle. Toactually check crossfeed operation, a complete, func-tional crossfeed system check should be accomplished.To do this, each engine should be operated from itscrossfeed position during the runup. The enginesshould be checked individually, and allowed to run atmoderate power (1,500 r.p.m. minimum) for at least 1minute to ensure that fuel flow can be established fromthe crossfeed source. Upon completion of the check,each engine should be operated for at least 1 minute atmoderate power from the main (takeoff) fuel tanks toreconfirm fuel flow prior to takeoff.

12-5

Ch 12.qxd 5/7/04 9:54 AM Page 12-5

12-6

This suggested check is not required prior to everyflight. Infrequently used, however, crossfeed lines areideal places for water and debris to accumulate unlessthey are used from time to time and drained using theirexternal drains during preflight. Crossfeed is ordinar-ily not used for completing single-engine flights whenan alternate airport is readily at hand, and it is neverused during takeoff or landings.

COMBUSTION HEATERCombustion heaters are common on multiengineairplanes. A combustion heater is best described asa small furnace that burns gasoline to produceheated air for occupant comfort and windshielddefogging. Most are thermostatically operated, andhave a separate hour meter to record time in servicefor maintenance purposes. Automatic overtemperatureprotection is provided by a thermal switch mounted onthe unit, which cannot be accessed in flight. Thisrequires the pilot or mechanic to actually visuallyinspect the unit for possible heat damage in order toreset the switch.

When finished with the combustion heater, a cooldown period is required. Most heaters require that out-side air be permitted to circulate through the unit for atleast 15 seconds in flight, or that the ventilation fan beoperated for at least 2 minutes on the ground. Failureto provide an adequate cool down will usually trip thethermal switch and render the heater inoperative untilthe switch is reset.

FLIGHT DIRECTOR/AUTOPILOTFlight director/autopilot (FD/AP) systems are commonon the better-equipped multiengine airplanes. Thesystem integrates pitch, roll, heading, altitude, andradio navigation signals in a computer. The outputs,called computed commands, are displayed on a flightcommand indicator, or FCI. The FCI replaces theconventional attitude indicator on the instrumentpanel. The FCI is occasionally referred to as a flightdirector indicator (FDI), or as an attitude directorindicator (ADI). The entire flight director/autopilotsystem is sometimes called an integrated flight con-trol system (IFCS) by some manufacturers. Othersmay use the term “automatic flight control system(AFCS).”

The FD/AP system may be employed at three differentlevels.

• Off (raw data).

• Flight director (computed commands).

• Autopilot.

With the system off, the FCI operates as an ordinaryattitude indicator. On most FCIs, the command barsare biased out of view when the flight director is off.

The pilot maneuvers the airplane as though the systemwere not installed.

To maneuver the airplane using the flight director, thepilot enters the desired modes of operation (heading,altitude, nav intercept, and tracking) on the FD/APmode controller. The computed flight commands arethen displayed to the pilot through either a single-cueor dual-cue system in the FCI. On a single-cue system,the commands are indicated by “V” bars. On adual-cue system, the commands are displayed ontwo separate command bars, one for pitch and onefor roll. To maneuver the airplane using computedcommands, the pilot “flies” the symbolic airplaneof the FCI to match the steering cues presented.

On most systems, to engage the autopilot the flightdirector must first be operating. At any time thereafter,the pilot may engage the autopilot through the modecontroller. The autopilot then maneuvers the airplaneto satisfy the computed commands of the flightdirector.

Like any computer, the FD/AP system will only dowhat it is told. The pilot must ensure that it has beenproperly programmed for the particular phase of flightdesired. The armed and/or engaged modes are usuallydisplayed on the mode controller or separate annunci-ator lights. When the airplane is being hand-flown, ifthe flight director is not being used at any particularmoment, it should be off so that the command bars arepulled from view.

Prior to system engagement, all FD/AP computer andtrim checks should be accomplished. Many newersystems cannot be engaged without the completion ofa self-test. The pilot must also be very familiar withvarious methods of disengagement, both normal andemergency. System details, including approvals andlimitations, can be found in the supplements sectionof the AFM/POH. Additionally, many avionics manu-facturers can provide informative pilot operatingguides upon request.

YAW DAMPERThe yaw damper is a servo that moves the rudder inresponse to inputs from a gyroscope or accelerometerthat detects yaw rate. The yaw damper minimizesmotion about the vertical axis caused by turbulence.(Yaw dampers on sweptwing airplanes provideanother, more vital function of damping dutch rollcharacteristics.) Occupants will feel a smoother ride,particularly if seated in the rear of the airplane, whenthe yaw damper is engaged. The yaw damper shouldbe off for takeoff and landing. There may be additionalrestrictions against its use during single-engine opera-tion. Most yaw dampers can be engaged independentlyof the autopilot.

Ch 12.qxd 5/7/04 9:54 AM Page 12-6

12-7

ALTERNATOR/GENERATORAlternator or generator paralleling circuitry matchesthe output of each engine’s alternator/generator so thatthe electrical system load is shared equally betweenthem. In the event of an alternator/generator failure,the inoperative unit can be isolated and the entireelectrical system powered from the remaining one.Depending upon the electrical capacity of the alter-nator/generator, the pilot may need to reduce theelectrical load (referred to as load shedding) whenoperating on a single unit. The AFM/POH will containsystem description and limitations.

NOSE BAGGAGE COMPARTMENTNose baggage compartments are common on multiengineairplanes (and are even found on a few single-engineairplanes). There is nothing strange or exotic about anose baggage compartment, and the usual guidanceconcerning observation of load limits applies. Theyare mentioned here in that pilots occasionally neglectto secure the latches properly, and therein lies thedanger. When improperly secured, the door will openand the contents may be drawn out, usually into thepropeller arc, and usually just after takeoff. Even whenthe nose baggage compartment is empty, airplaneshave been lost when the pilot became distracted by theopen door. Security of the nose baggage compartmentlatches and locks is a vital preflight item.

Most airplanes will continue to fly with a nose bag-gage door open. There may be some buffeting fromthe disturbed airflow and there will be an increase innoise. Pilots should never become so preoccupiedwith an open door (of any kind) that they fail to flythe airplane.

Inspection of the compartment interior is also animportant preflight item. More than one pilot has beensurprised to find a supposedly empty compartmentpacked to capacity or loaded with ballast. The towbars, engine inlet covers, windshield sun screens, oilcontainers, spare chocks, and miscellaneous smallhand tools that find their way into baggage compart-ments should be secured to prevent damage fromshifting in flight.

ANTI-ICING/DEICINGAnti-icing/deicing equipment is frequently installed onmultiengine airplanes and consists of a combination ofdifferent systems. These may be classified as eitheranti-icing or deicing, depending upon function. Thepresence of anti-icing and deicing equipment, eventhough it may appear elaborate and complete, does notnecessarily mean that the airplane is approved forflight in icing conditions. The AFM/POH, placards,and even the manufacturer should be consulted forspecific determination of approvals and limitations.

Anti-icing equipment is provided to prevent ice fromforming on certain protected surfaces. Anti-icingequipment includes heated pitot tubes, heated or non-icing static ports and fuel vents, propeller blades withelectrothermal boots or alcohol slingers, windshieldswith alcohol spray or electrical resistance heating,windshield defoggers, and heated stall warning liftdetectors. On many turboprop engines, the “lip”surrounding the air intake is heated either electricallyor with bleed air. In the absence of AFM/POH guidanceto the contrary, anti-icing equipment is actuated prior toflight into known or suspected icing conditions.

Deicing equipment is generally limited to pneumaticboots on wing and tail leading edges. Deicing equip-ment is installed to remove ice that has already formedon protected surfaces. Upon pilot actuation, the bootsinflate with air from the pneumatic pumps to break offaccumulated ice. After a few seconds of inflation, theyare deflated back to their normal position with theassistance of a vacuum. The pilot monitors the buildupof ice and cycles the boots as directed in theAFM/POH. An ice light on the left engine nacelleallows the pilot to monitor wing ice accumulation atnight.

Other airframe equipment necessary for flight in icingconditions includes an alternate induction air sourceand an alternate static system source. Ice tolerantantennas will also be installed.

In the event of impact ice accumulating over normalengine air induction sources, carburetor heat (carbu-reted engines) or alternate air (fuel injected engines)should be selected. Ice buildup on normal inductionsources can be detected by a loss of engine r.p.m. withfixed-pitch propellers and a loss of manifold pressurewith constant-speed propellers. On some fuel injectedengines, an alternate air source is automaticallyactivated with blockage of the normal air source.

An alternate static system provides an alternate sourceof static air for the pitot-static system in the unlikelyevent that the primary static source becomes blocked.In non-pressurized airplanes, most alternate staticsources are plumbed to the cabin. On pressurized air-planes, they are usually plumbed to a non-pressurizedbaggage compartment. The pilot must activate thealternate static source by opening a valve or a fitting inthe cockpit. Upon activation, the airspeed indicator,altimeter, and the vertical speed indicator (VSI) will beaffected and will read somewhat in error. A correctiontable is frequently provided in the AFM/POH.

Anti-icing/deicing equipment only eliminates ice fromthe protected surfaces. Significant ice accumulationsmay form on unprotected areas, even with proper useof anti-ice and deice systems. Flight at high angles of

Ch 12.qxd 5/7/04 9:54 AM Page 12-7

12-8

attack or even normal climb speeds will permit signifi-cant ice accumulations on lower wing surfaces, whichare unprotected. Many AFM/POHs mandate minimumspeeds to be maintained in icing conditions. Degradationof all flight characteristics and large performance lossescan be expected with ice accumulations. Pilots shouldnot rely upon the stall warning devices for adequate stallwarning with ice accumulations.

Ice will accumulate unevenly on the airplane. It willadd weight and drag (primarily drag), and decreasethrust and lift. Even wing shape affects ice accumu-lation; thin airfoil sections are more prone to iceaccumulation than thick, highly-cambered sections.For this reason certain surfaces, such as the horizontalstabilizer, are more prone to icing than the wing. Withice accumulations, landing approaches should be madewith a minimum wing flap setting (flap extensionincreases the angle of attack of the horizontal stabilizer)and with an added margin of airspeed. Sudden and largeconfiguration and airspeed changes should be avoided.

Unless otherwise recommended in the AFM/POH, theautopilot should not be used in icing conditions.Continuous use of the autopilot will mask trim andhandling changes that will occur with ice accumula-tion. Without this control feedback, the pilot may notbe aware of ice accumulation building to hazardouslevels. The autopilot will suddenly disconnect when itreaches design limits and the pilot may find the airplanehas assumed unsatisfactory handling characteristics.

The installation of anti-ice/deice equipment on air-planes without AFM/POH approval for flight into icingconditions is to facilitate escape when such conditionsare inadvertently encountered. Even with AFM/POHapproval, the prudent pilot will avoid icing conditionsto the maximum extent practicable, and avoid extendedflight in any icing conditions. No multiengine airplaneis approved for flight into severe icing conditions, andnone are intended for indefinite flight in continuousicing conditions.

PERFORMANCE AND LIMITATIONSDiscussion of performance and limitations requires thedefinition of several terms.

• Accelerate-stop distance is the runway lengthrequired to accelerate to a specified speed (eitherVR or VLOF, as specified by the manufacturer),experience an engine failure, and bring the air-plane to a complete stop.

• Accelerate-go distance is the horizontal dis-tance required to continue the takeoff and climbto 50 feet, assuming an engine failure at VR orVLOF, as specified by the manufacturer.

• Climb gradient is a slope most frequentlyexpressed in terms of altitude gain per 100 feetof horizontal distance, whereupon it is stated asa percentage. A 1.5 percent climb gradient is analtitude gain of one and one-half feet per 100 feetof horizontal travel. Climb gradient may also beexpressed as a function of altitude gain per nau-tical mile, or as a ratio of the horizontal distanceto the vertical distance (50:1, for example).Unlike rate of climb, climb gradient is affectedby wind. Climb gradient is improved with aheadwind component, and reduced with a tail-wind component. [Figure 12-5]

• The all-engine service ceiling of multiengineairplanes is the highest altitude at which the air-plane can maintain a steady rate of climb of 100f.p.m. with both engines operating. The airplanehas reached its absolute ceiling when climb isno longer possible.

• The single-engine service ceiling is reachedwhen the multiengine airplane can no longermaintain a 50 f.p.m. rate of climb with one engineinoperative, and its single-engine absolute ceil-ing when climb is no longer possible.

The takeoff in a multiengine airplane should beplanned in sufficient detail so that the appropriateaction is taken in the event of an engine failure. Thepilot should be thoroughly familiar with the airplane’sperformance capabilities and limitations in order tomake an informed takeoff decision as part of the pre-flight planning. That decision should be reviewed asthe last item of the “before takeoff” checklist.

In the event of an engine failure shortly after takeoff,the decision is basically one of continuing flight orlanding, even off-airport. If single-engine climbperformance is adequate for continued flight, andthe airplane has been promptly and correctly con-figured, the climb after takeoff may be continued. Ifsingle-engine climb performance is such that climbis unlikely or impossible, a landing will have to bemade in the most suitable area. To be avoided aboveall is attempting to continue flight when it is notwithin the airplane’s performance capability to doso. [Figure 12-6]

Takeoff planning factors include weight and balance,airplane performance (both single and multiengine),runway length, slope and contamination, terrain andobstacles in the area, weather conditions, and pilotproficiency. Most multiengine airplanes haveAFM/POH performance charts and the pilot shouldbe highly proficient in their use. Prior to takeoff, themultiengine pilot should ensure that the weight andbalance limitations have been observed, the runway

Ch 12.qxd 5/7/04 9:54 AM Page 12-8

length is adequate, the normal flightpath will clear obsta-cles and terrain, and that a definitive course of action hasbeen planned in the event of an engine failure.

The regulations do not specifically require that therunway length be equal to or greater than the accel-erate-stop distance. Most AFM/POHs publishaccelerate-stop distances only as an advisory. It

becomes a limitation only when published in thelimitations section of the AFM/POH. Experiencedmultiengine pilots, however, recognize the safetymargin of runway lengths in excess of the bare min-imum required for normal takeoff. They will insiston runway lengths of at least accelerate-stop dis-tance as a matter of safety and good operatingpractice.

50 ftVR / VLOFBrake

Release

Accelerate-Stop Distance

Accelerate-Go Distance

500 ft

VLOFBrakeRelease

5,000 ft

10:1 or 10 Percent Climb Gradient

Figure 12-5. Accelerate-stop distance, accelerate-go distance, and climb gradient.

Figure 12-6. Area of decision.

12-9

VXSEVYSE

Gear Up and Loss of One Engine

Best Rate of ClimbBest Angle of Climb

Decision Area

VR / VLOF

BrakeRelease

ENGINE FAILURE AFTER LIFT-OFF

Ch 12.qxd 5/7/04 9:54 AM Page 12-9

The multiengine pilot must keep in mind that theaccelerate-go distance, as long as it is, has onlybrought the airplane, under ideal circumstances, to apoint a mere 50 feet above the takeoff elevation. Toachieve even this meager climb, the pilot had to instan-taneously recognize and react to an unanticipatedengine failure, retract the landing gear, identify andfeather the correct engine, all the while maintainingprecise airspeed control and bank angle as the airspeedis nursed to VYSE. Assuming flawless airmanship thusfar, the airplane has now arrived at a point little morethan one wingspan above the terrain, assuming it wasabsolutely level and without obstructions.

With (for the purpose of illustration) a net 150 f.p.m.rate of climb at a 90-knot VYSE, it will take approxi-mately 3 minutes to climb an additional 450 feet to reach500 feet AGL. In doing so, the airplane will havetraveled an additional 5 nautical miles beyond theoriginal accelerate-go distance, with a climb gradientof about 1.6 percent. A turn of any consequence, suchas to return to the airport, will seriously degrade thealready marginal climb performance.

Not all multiengine airplanes have published acceler-ate-go distances in their AFM/POH, and fewer stillpublish climb gradients. When such information ispublished, the figures will have been determined underideal flight testing conditions. It is unlikely that thisperformance will be duplicated in service conditions.

The point of the foregoing is to illustrate the marginalclimb performance of a multiengine airplane thatsuffers an engine failure shortly after takeoff, evenunder ideal conditions. The prudent multienginepilot should pick a point in the takeoff and climbsequence in advance. If an engine fails before this point,the takeoff should be rejected, even if airborne, for alanding on whatever runway or surface lies essentiallyahead. If an engine fails after this point, the pilot shouldpromptly execute the appropriate engine failure proce-dure and continue the climb, assuming the performancecapability exists. As a general recommendation, if thelanding gear has not been selected up, the takeoffshould be rejected, even if airborne.

As a practical matter for planning purposes, the optionof continuing the takeoff probably does not exist unlessthe published single-engine rate-of-climb performanceis at least 100 to 200 f.p.m. Thermal turbulence, windgusts, engine and propeller wear, or poor technique inairspeed, bank angle, and rudder control can easilynegate even a 200 f.p.m. rate of climb.

WEIGHT AND BALANCEThe weight and balance concept is no different thanthat of a single-engine airplane. The actual execution,however, is almost invariably more complex due to a

number of new loading areas, including nose and aftbaggage compartments, nacelle lockers, main fueltanks, aux fuel tanks, nacelle fuel tanks, and numerousseating options in a variety of interior configurations.The flexibility in loading offered by the multiengineairplane places a responsibility on the pilot to addressweight and balance prior to each flight.

The terms “empty weight, licensed empty weight,standard empty weight, and basic empty weight” asthey appear on the manufacturer’s original weight andbalance documents are sometimes confused by pilots.

In 1975, the General Aviation ManufacturersAssociation (GAMA) adopted a standardized formatfor AFM/POHs. It was implemented by mostmanufacturers in model year 1976. Airplanes whosemanufacturers conform to the GAMA standards utilizethe following terminology for weight and balance:

Standard empty weight+ Optional equipment= Basic empty weight

Standard empty weight is the weight of the standardairplane, full hydraulic fluid, unusable fuel, and fulloil. Optional equipment includes the weight of allequipment installed beyond standard. Basic emptyweight is the standard empty weight plus optionalequipment. Note that basic empty weight includes nousable fuel, but full oil.

Airplanes manufactured prior to the GAMA formatgenerally utilize the following terminology for weightand balance, although the exact terms may vary some-what:

Empty weight+ Unusable fuel= Standard empty weight

Standard empty weight+ Optional equipment= Licensed empty weight

Empty weight is the weight of the standard airplane,full hydraulic fluid and undrainable oil. Unusable fuelis the fuel remaining in the airplane not available tothe engines. Standard empty weight is the emptyweight plus unusable fuel. When optional equipmentis added to the standard empty weight, the result islicensed empty weight. Licensed empty weight,therefore, includes the standard airplane, optionalequipment, full hydraulic fluid, unusable fuel, andundrainable oil.

The major difference between the two formats(GAMA and the old) is that basic empty weightincludes full oil, and licensed empty weight does not.

12-10

Ch 12.qxd 5/7/04 9:54 AM Page 12-10

Oil must always be added to any weight and balanceutilizing a licensed empty weight.

When the airplane is placed in service, amendedweight and balance documents are prepared by appro-priately rated maintenance personnel to reflect changesin installed equipment. The old weight and balancedocuments are customarily marked “superseded” andretained in the AFM/POH. Maintenance personnel areunder no regulatory obligation to utilize the GAMAterminology, so weight and balance documentssubsequent to the original may use a variety ofterms. Pilots should use care to determine whetheror not oil has to be added to the weight and balancecalculations or if it is already included in the figuresprovided.

The multiengine airplane is where most pilotsencounter the term “zero fuel weight” for the first time.Not all multiengine airplanes have a zero fuel weightlimitation published in their AFM/POH, but many do.Zero fuel weight is simply the maximum allowableweight of the airplane and payload, assuming there isno usable fuel on board. The actual airplane is notdevoid of fuel at the time of loading, of course. This ismerely a calculation that assumes it was. If a zero fuelweight limitation is published, then all weight inexcess of that figure must consist of usable fuel. Thepurpose of a zero fuel weight is to limit load forces onthe wing spars with heavy fuselage loads.

Assume a hypothetical multiengine airplane with thefollowing weights and capacities:

Basic empty weight . . . . . . . . . . . . . . . . .3,200 lb.

Zero fuel weight . . . . . . . . . . . . . . . . . . . .4,400 lb.

Maximum takeoff weight . . . . . . . . . . . . .5,200 lb.

Maximum usable fuel . . . . . . . . . . . . . . . .180 gal.

1. Calculate the useful load:

Maximum takeoff weight . . . . . . . . . . . . .5,200 lb.

Basic empty weight . . . . . . . . . . . . . . . . .-3,200 lb.

Useful load . . . . . . . . . . . . . . . . . . . . . . . .2,000 lb.

The useful load is the maximum combination of usablefuel, passengers, baggage, and cargo that the airplaneis capable of carrying.

2. Calculate the payload:

Zero fuel weight . . . . . . . . . . . . . . . . . . . . 4,400 lb.

Basic empty weight . . . . . . . . . . . . . . . . . -3,200 lb.Payload . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,200 lb.

The payload is the maximum combination of passen-gers, baggage, and cargo that the airplane is capableof carrying. A zero fuel weight, if published, is thelimiting weight.

3. Calculate the fuel capacity at maximum payload(1,200 lb.):

Maximum takeoff weight . . . . . . . . . . . . .5,200 lb.

Zero fuel weight . . . . . . . . . . . . . . . . . . .-4,400 lb.

Fuel allowed . . . . . . . . . . . . . . . . . . . . . . . .800 lb.

Assuming maximum payload, the only weight permit-ted in excess of the zero fuel weight must consist ofusable fuel. In this case, 133.3 gallons.

4. Calculate the payload at maximum fuel capacity(180 gal.):

Basic empty weight . . . . . . . . . . . . . . . . .3,200 lb.

Maximum usable fuel . . . . . . . . . . . . . . .+1,080 lb.

Weight with max. fuel . . . . . . . . . . . . . . .4,280 lb.

Maximum takeoff weight . . . . . . . . . . . . .5,200 lb.

Weight with max. fuel . . . . . . . . . . . . . . .-4,280 lb.

Payload allowed . . . . . . . . . . . . . . . . . . . . .920 lb.

Assuming maximum fuel, the payload is the differencebetween the weight of the fueled airplane and the max-imum takeoff weight.

Some multiengine airplanes have a ramp weight,which is in excess of the maximum takeoff weight. Theramp weight is an allowance for fuel that would beburned during taxi and runup, permitting a takeoff atfull maximum takeoff weight. The airplane mustweigh no more than maximum takeoff weight at thebeginning of the takeoff roll.

A maximum landing weight is a limitation againstlanding at a weight in excess of the published value.This requires preflight planning of fuel burn to ensurethat the airplane weight upon arrival at destination willbe at or below the maximum landing weight. In theevent of an emergency requiring an immediate land-ing, the pilot should recognize that the structuralmargins designed into the airplane are not fullyavailable when over landing weight. An overweightlanding inspection may be advisable—the servicemanual or manufacturer should be consulted.

12-11

Ch 12.qxd 5/7/04 9:54 AM Page 12-11

Although the foregoing problems only dealt withweight, the balance portion of weight and balanceis equally vital. The flight characteristics of themultiengine airplane will vary significantly withshifts of the center of gravity (CG) within theapproved envelope.

At forward CGs, the airplane will be more stable, witha slightly higher stalling speed, a slightly slowercruising speed, and favorable stall characteristics.At aft CGs, the airplane will be less stable, with aslightly lower stalling speed, a slightly faster cruisingspeed, and less desirable stall characteristics. ForwardCG limits are usually determined in certification byelevator/stabilator authority in the landing round-out. Aft CG limits are determined by the minimumacceptable longitudinal stability. It is contrary to theairplane’s operating limitations and the Code ofFederal Regulations (CFR) to exceed any weightand balance parameter.

Some multiengine airplanes may require ballast toremain within CG limits under certain loading condi-tions. Several models require ballast in the aft baggagecompartment with only a student and instructor onboard to avoid exceeding the forward CG limit.When passengers are seated in the aft-most seats ofsome models, ballast or baggage may be required inthe nose baggage compartment to avoid exceedingthe aft CG limit. The pilot must direct the seating ofpassengers and placement of baggage and cargo toachieve a center of gravity within the approvedenvelope. Most multiengine airplanes have generalloading recommendations in the weight and balancesection of the AFM/POH. When ballast is added, itmust be securely tied down and it must not exceedthe maximum allowable floor loading.

Some airplanes make use of a special weight andbalance plotter. It consists of several movable partsthat can be adjusted over a plotting board on whichthe CG envelope is printed. The reverse side of thetypical plotter contains general loading recommen-dations for the particular airplane. A pencil line plotcan be made directly on the CG envelope imprintedon the working side of the plotting board. This plotcan easily be erased and recalculated anew for eachflight. This plotter is to be used only for the makeand model airplane for which it was designed.

GROUND OPERATIONGood habits learned with single-engine airplanes aredirectly applicable to multiengine airplanes for pre-flight and engine start. Upon placing the airplane inmotion to taxi, the new multiengine pilot will noticeseveral differences, however. The most obvious isthe increased wingspan and the need for even

greater vigilance while taxiing in close quarters.Ground handling may seem somewhat ponderousand the multiengine airplane will not be as nimbleas the typical two- or four-place single-engine airplane.As always, use care not to ride the brakes by keepingengine power to a minimum. One ground handlingadvantage of the multiengine airplane over single-engine airplanes is the differential power capability.Turning with an assist from differential power mini-mizes both the need for brakes during turns and theturning radius.

The pilot should be aware, however, that making asharp turn assisted by brakes and differential powercan cause the airplane to pivot about a stationaryinboard wheel and landing gear. This is abuse forwhich the airplane was not designed and should beguarded against.

Unless otherwise directed by the AFM/POH, allground operations should be conducted with the cowlflaps fully open. The use of strobe lights is normallydeferred until taxiing onto the active runway.

NORMAL AND CROSSWIND TAKEOFF AND CLIMBWith the “before takeoff” checklist complete andair traffic control (ATC) clearance received, the air-plane should be taxied into position on the runwaycenterline. If departing from an airport without anoperating control tower, a careful check forapproaching aircraft should be made along with aradio advisory on the appropriate frequency. Sharpturns onto the runway combined with a rollingtakeoff are not a good operating practice and maybe prohibited by the AFM/POH due to the possibilityof “unporting” a fuel tank pickup. (The takeoff itselfmay be prohibited by the AFM/POH under any circum-stances below certain fuel levels.) The flight controlsshould be positioned for a crosswind, if present.Exterior lights such as landing and taxi lights, andwingtip strobes should be illuminated immediatelyprior to initiating the takeoff roll, day or night. Ifholding in takeoff position for any length of time,particularly at night, the pilot should activate allexterior lights upon taxiing into position.

Takeoff power should be set as recommended in theAFM/POH. With normally aspirated (non-tur-bocharged) engines, this will be full throttle. Fullthrottle is also used in most turbocharged engines.There are some turbocharged engines, however,that require the pilot to set a specific power setting,usually just below red line manifold pressure. Thisyields takeoff power with less than full throttle travel.

12-12

Ch 12.qxd 5/7/04 9:54 AM Page 12-12

Turbocharged engines often require special consid-eration. Throttle motion with turbocharged enginesshould be exceptionally smooth and deliberate. It isacceptable, and may even be desirable, to hold theairplane in position with brakes as the throttles areadvanced. Brake release customarily occurs after sig-nificant boost from the turbocharger is established. Thisprevents wasting runway with slow, partial throttleacceleration as the engine power is increased. If runwaylength or obstacle clearance is critical, full power shouldbe set before brake release, as specified in the perform-ance charts.

As takeoff power is established, initial attention shouldbe divided between tracking the runway centerline andmonitoring the engine gauges. Many novice multi-engine pilots tend to fixate on the airspeed indicatorjust as soon as the airplane begins its takeoff roll.Instead, the pilot should confirm that both enginesare developing full-rated manifold pressure andr.p.m., and that the fuel flows, fuel pressures, exhaustgas temperatures (EGTs), and oil pressures are matchedin their normal ranges. A directed and purposeful scanof the engine gauges can be accomplished well beforethe airplane approaches rotation speed. If a crosswind ispresent, the aileron displacement in the direction of thecrosswind may be reduced as the airplane accelerates.The elevator/stabilator control should be held neutralthroughout.

Full rated takeoff power should be used for every take-off. Partial power takeoffs are not recommended.There is no evidence to suggest that the life of modernreciprocating engines is prolonged by partial powertakeoffs. Paradoxically, excessive heat and enginewear can occur with partial power as the fuel meteringsystem will fail to deliver the slightly over-richmixture vital for engine cooling during takeoff.

There are several key airspeeds to be noted during thetakeoff and climb sequence in any twin. The first speedto consider is VMC. If an engine fails below VMC whilethe airplane is on the ground, the takeoff must berejected. Directional control can only be maintained bypromptly closing both throttles and using rudder andbrakes as required. If an engine fails below VMC whileairborne, directional control is not possible with theremaining engine producing takeoff power. On take-offs, therefore, the airplane should never be airbornebefore the airspeed reaches and exceeds VMC. Pilotsshould use the manufacturer’s recommended rotationspeed (VR) or lift-off speed (VLOF). If no such speedsare published, a minimum of VMC plus 5 knots shouldbe used for VR.

The rotation to a takeoff pitch attitude is donesmoothly. With a crosswind, the pilot should ensure

that the landing gear does not momentarily touch therunway after the airplane has lifted off, as a side driftwill be present. The rotation may be accomplishedmore positively and/or at a higher speed under theseconditions. However, the pilot should keep in mindthat the AFM/POH performance figures for accelerate-stop distance, takeoff ground roll, and distance to clearan obstacle were calculated at the recommended VRand/or VLOF speed.

After lift-off, the next consideration is to gain alti-tude as rapidly as possible. After leaving the ground,altitude gain is more important than achieving anexcess of airspeed. Experience has shown thatexcessive speed cannot be effectively converted intoaltitude in the event of an engine failure. Altitudegives the pilot time to think and react. Therefore, theairplane should be allowed to accelerate in a shallowclimb to attain VY, the best all-engine rate-of-climbspeed. VY should then be maintained until a safesingle-engine maneuvering altitude, consideringterrain and obstructions, is achieved.

To assist the pilot in takeoff and initial climb profile,some AFM/POHs give a “50-foot” or “50-foot barrier”speed to use as a target during rotation, lift-off, andacceleration to VY.

Landing gear retraction should normally occur after apositive rate of climb is established. SomeAFM/POHs direct the pilot to apply the wheel brakesmomentarily after lift-off to stop wheel rotation priorto landing gear retraction. If flaps were extended fortakeoff, they should be retracted as recommended inthe AFM/POH.

Once a safe single-engine maneuvering altitude hasbeen reached, typically a minimum of 400-500 feetAGL, the transition to an enroute climb speed shouldbe made. This speed is higher than VY and is usuallymaintained to cruising altitude. Enroute climb speedgives better visibility, increased engine cooling, and ahigher groundspeed. Takeoff power can be reduced, ifdesired, as the transition to enroute climb speed ismade.

Some airplanes have a climb power setting publishedin the AFM/POH as a recommendation (or sometimesas a limitation), which should then be set for enrouteclimb. If there is no climb power setting published, it iscustomary, but not a requirement, to reduce manifoldpressure and r.p.m. somewhat for enroute climb. Thepropellers are usually synchronized after the firstpower reduction and the yaw damper, if installed,engaged. The AFM/POH may also recommend leaning

12-13

Ch 12.qxd 5/7/04 9:54 AM Page 12-13

12-14

the mixtures during climb. The “climb” checklistshould be accomplished as traffic and work load allow.[Figure 12-7]

LEVEL OFF AND CRUISEUpon leveling off at cruising altitude, the pilot shouldallow the airplane to accelerate at climb power untilcruising airspeed is achieved, then cruise power andr.p.m. should be set. To extract the maximum cruiseperformance from any airplane, the power settingtables provided by the manufacturer should be closelyfollowed. If the cylinder head and oil temperatures arewithin their normal ranges, the cowl flaps may beclosed. When the engine temperatures have stabilized,the mixtures may be leaned per AFM/POH recommen-dations. The remainder of the “cruise” checklist shouldbe completed by this point.

Fuel management in multiengine airplanes is oftenmore complex than in single-engine airplanes.Depending upon system design, the pilot may need toselect between main tanks and auxiliary tanks, oreven employ fuel transfer from one tank to another.In complex fuel systems, limitations are often foundrestricting the use of some tanks to level flight only,or requiring a reserve of fuel in the main tanks fordescent and landing. Electric fuel pump operation canvary widely among different models also, particularlyduring tank switching or fuel transfer. Some fuelpumps are to be on for takeoff and landing; others areto be off. There is simply no substitute for thorough

systems and AFM/POH knowledge when operatingcomplex aircraft.

NORMAL APPROACH AND LANDINGGiven the higher cruising speed (and frequently, alti-tude) of multiengine airplanes over most single-engineairplanes, the descent must be planned in advance. Ahurried, last minute descent with power at or near idleis inefficient and can cause excessive engine cooling.It may also lead to passenger discomfort, particularlyif the airplane is unpressurized. As a rule of thumb, ifterrain and passenger conditions permit, a maximumof a 500 f.p.m. rate of descent should be planned.Pressurized airplanes can plan for higher descent rates,if desired.

In a descent, some airplanes require a minimum EGT,or may have a minimum power setting or cylinderhead temperature to observe. In any case, combi-nations of very low manifold pressure and highr.p.m. settings are strongly discouraged by enginemanufacturers. If higher descent rates are necessary,the pilot should consider extending partial flaps orlowering the landing gear before retarding the powerexcessively. The “descent” checklist should be initiatedupon leaving cruising altitude and completed beforearrival in the terminal area. Upon arrival in the terminalarea, pilots are encouraged to turn on their landingand recognition lights when operating below10,000 feet, day or night, and especially whenoperating within 10 miles of any airport or in conditionsof reduced visibility.

Figure 12-7.Takeoff and climb profile.

Lift-offPublished VR or VLOF

if not Published,VMC + 5 Knots

Positive Rate - Gear Up Climb at VY

500 ft1. Accelerate to Cruise Climb2. Set Climb Power3. Climb Checklist

Ch 12.qxd 5/7/04 9:54 AM Page 12-14

The traffic pattern and approach are typically flown atsomewhat higher indicated airspeeds in a multiengineairplane contrasted to most single-engine airplanes.The pilot may allow for this through an early start onthe “before landing” checklist. This provides time forproper planning, spacing, and thinking well ahead ofthe airplane. Many multiengine airplanes have partialflap extension speeds above VFE, and partial flaps canbe deployed prior to traffic pattern entry. Normally, thelanding gear should be selected and confirmed downwhen abeam the intended point of landing as the down-wind leg is flown. [Figure 12-8]

The Federal Aviation Administration (FAA) recom-mends a stabilized approach concept. To the greatestextent practical, on final approach and within 500 feetAGL, the airplane should be on speed, in trim, con-figured for landing, tracking the extended centerlineof the runway, and established in a constant angle ofdescent towards an aim point in the touchdownzone. Absent unusual flight conditions, only minorcorrections will be required to maintain this approachto the roundout and touchdown.

The final approach should be made with power andat a speed recommended by the manufacturer; if a rec-ommended speed is not furnished, the speed should beno slower than the single-engine best rate-of-climbspeed (VYSE) until short final with the landing assured,but in no case less than critical engine-out minimumcontrol speed (VMC). Some multiengine pilots preferto delay full flap extension to short final with the land-ing assured. This is an acceptable technique with appro-priate experience and familiarity with the airplane.

In the roundout for landing, residual power is gradu-ally reduced to idle. With the higher wing loading ofmultiengine airplanes and with the drag from twowindmilling propellers, there will be minimal float.

Full stall landings are generally undesirable in twins. Theairplane should be held off as with a high performancesingle-engine model, allowing touchdown of the mainwheels prior to a full stall.

Under favorable wind and runway conditions, thenosewheel can be held off for best aerodynamic brak-ing. Even as the nosewheel is gently lowered to therunway centerline, continued elevator back pressurewill greatly assist the wheel brakes in stopping theairplane.

If runway length is critical, or with a strong crosswind,or if the surface is contaminated with water, ice orsnow, it is undesirable to rely solely on aerodynamicbraking after touchdown. The full weight of the air-plane should be placed on the wheels as soon aspracticable. The wheel brakes will be more effectivethan aerodynamic braking alone in decelerating theairplane.

Once on the ground, elevator back pressure should beused to place additional weight on the main wheels andto add additional drag. When necessary, wing flapretraction will also add additional weight to the wheelsand improve braking effectivity. Flap retraction duringthe landing rollout is discouraged, however, unlessthere is a clear, operational need. It should not beaccomplished as routine with each landing.

Some multiengine airplanes, particularly those of thecabin class variety, can be flown through the roundoutand touchdown with a small amount of power. This isan acceptable technique to prevent high sink rates andto cushion the touchdown. The pilot should keep inmind, however, that the primary purpose in landing isto get the airplane down and stopped. This techniqueshould only be attempted when there is a generous

Approaching Traffic Pattern1. Descent Checklist2. Reduce to Traffic Pattern Airspeed and Altitude

Downwind1. Flaps - Approach Position2. Gear Down3. Before Landing Checklist

Base Leg1. Gear-Check Down2. Check for Conflicting Traffic

Final1. Gear-Check Down2. Flaps-Landing Position

Airspeed- 1.3 Vs0 orManufacturers Recommended

Figure 12-8. Normal two-engine approach and landing.

12-15

Ch 12.qxd 5/7/04 9:54 AM Page 12-15

12-16

margin of runway length. As propeller blast flowsdirectly over the wings, lift as well as thrust is produced.The pilot should taxi clear of the runway as soon asspeed and safety permit, and then accomplish the “afterlanding” checklist. Ordinarily, no attempt should bemade to retract the wing flaps or perform other check-list duties until the airplane has been brought to a haltwhen clear of the active runway. Exceptions to thiswould be the rare operational needs discussed above,to relieve the weight from the wings and place it on thewheels. In these cases, AFM/POH guidance should befollowed. The pilot should not indiscriminately reachout for any switch or control on landing rollout. Aninadvertent landing gear retraction while meaning toretract the wing flaps may result.

CROSSWIND APPROACH AND LANDINGThe multiengine airplane is often easier to land in acrosswind than a single-engine airplane due to itshigher approach and landing speed. In any event, theprinciples are no different between singles and twins.Prior to touchdown, the longitudinal axis must bealigned with the runway centerline to avoid landinggear side loads.

The two primary methods, crab and wing-low, aretypically used in conjunction with each other. Assoon as the airplane rolls out onto final approach, thecrab angle to track the extended runway centerline isestablished. This is coordinated flight with adjust-ments to heading to compensate for wind drift eitherleft or right. Prior to touchdown, the transition to asideslip is made with the upwind wing lowered andopposite rudder applied to prevent a turn. The airplanetouches down on the landing gear of the upwind wingfirst, followed by that of the downwind wing, andthen the nose gear. Follow-through with the flightcontrols involves an increasing application of aileroninto the wind until full control deflection is reached.

The point at which the transition from the crab to thesideslip is made is dependent upon pilot familiaritywith the airplane and experience. With high skill andexperience levels, the transition can be made duringthe roundout just before touchdown. With lesser skill

and experience levels, the transition is made atincreasing distances from the runway. Some multi-engine airplanes (as some single-engine airplanes)have AFM/POH limitations against slips in excess ofa certain time period; 30 seconds, for example. This isto prevent engine power loss from fuel starvation asthe fuel in the tank of the lowered wing flows towardsthe wingtip, away from the fuel pickup point. Thistime limit must be observed if the wing-low methodis utilized.

Some multiengine pilots prefer to use differentialpower to assist in crosswind landings. The asym-metrical thrust produces a yawing moment littledifferent from that produced by the rudder. Whenthe upwind wing is lowered, power on the upwindengine is increased to prevent the airplane fromturning. This alternate technique is completelyacceptable, but most pilots feel they can react tochanging wind conditions quicker with rudder andaileron than throttle movement. This is especiallytrue with turbocharged engines where the throttleresponse may lag momentarily. The differentialpower technique should be practiced with aninstructor familiar with it before being attemptedalone.

SHORT-FIELD TAKEOFF AND CLIMBThe short-field takeoff and climb differs from thenormal takeoff and climb in the airspeeds and initialclimb profile. Some AFM/POHs give separateshort-field takeoff procedures and performancecharts that recommend specific flap settings and air-speeds. Other AFM/POHs do not provide separateshort-field procedures. In the absence of such specificprocedures, the airplane should be operated only asrecommended in the AFM/POH. No operations shouldbe conducted contrary to the recommendations in theAFM/POH.

On short-field takeoffs in general, just after rotationand lift-off, the airplane should be allowed to acceler-ate to VX, making the initial climb over obstacles atVX and transitioning to VY as obstacles are cleared.[Figure 12-9]

Figure 12-9. Short-field takeoff and climb.

VX

VY

50 ft

Ch 12.qxd 5/7/04 9:54 AM Page 12-16

12-17

When partial flaps are recommended for short-fieldtakeoffs, many light-twins have a strong tendency tobecome airborne prior to VMC plus 5 knots. Attemptingto prevent premature lift-off with forward elevatorpressure results in wheelbarrowing. To prevent this,allow the airplane to become airborne, but only a fewinches above the runway. The pilot should be preparedto promptly abort the takeoff and land in the event ofengine failure on takeoff with landing gear and flapsextended at airspeeds below VX.

Engine failure on takeoff, particularly with obstruc-tions, is compounded by the low airspeeds and steepclimb attitudes utilized in short-field takeoffs. VX andVXSE are often perilously close to VMC, leaving scantmargin for error in the event of engine failure as VXSEis assumed. If flaps were used for takeoff, the enginefailure situation becomes even more critical due to theadditional drag incurred. If VX is less than 5 knotshigher than VMC, give strong consideration to reducinguseful load or using another runway in order toincrease the takeoff margins so that a short-fieldtechnique will not be required.

SHORT-FIELD APPROACH AND LANDINGThe primary elements of a short-field approach andlanding do not differ significantly from a normalapproach and landing. Many manufacturers do notpublish short-field landing techniques or performancecharts in the AFM/POH. In the absence of specificshort-field approach and landing procedures, theairplane should be operated as recommended in theAFM/POH. No operations should be conductedcontrary to the AFM/POH recommendations.

The emphasis in a short-field approach is on configu-ration (full flaps), a stabilized approach with a constantangle of descent, and precise airspeed control. As partof a short-field approach and landing procedure,some AFM/POHs recommend a slightly slower thannormal approach airspeed. If no such slower speed ispublished, use the AFM/POH-recommended normalapproach speed.

Full flaps are used to provide the steepest approachangle. If obstacles are present, the approach should beplanned so that no drastic power reductions arerequired after they are cleared. The power should besmoothly reduced to idle in the roundout prior totouchdown. Pilots should keep in mind that the pro-peller blast blows over the wings, providing some liftin addition to thrust. Significantly reducing power justafter obstacle clearance usually results in a sudden,high sink rate that may lead to a hard landing.

After the short-field touchdown, maximum stoppingeffort is achieved by retracting the wing flaps, addingback pressure to the elevator/stabilator, and applyingheavy braking. However, if the runway length permits,the wing flaps should be left in the extended positionuntil the airplane has been stopped clear of the runway.There is always a significant risk of retracting the land-ing gear instead of the wing flaps when flap retractionis attempted on the landing rollout.

Landing conditions that involve either a short-field,high-winds or strong crosswinds are just about the onlysituations where flap retraction on the landing rolloutshould be considered. When there is an operationalneed to retract the flaps just after touchdown, it mustbe done deliberately, with the flap handle positivelyidentified before it is moved.

GO-AROUNDWhen the decision to go around is made, the throttlesshould be advanced to takeoff power. With adequateairspeed, the airplane should be placed in a climb pitchattitude. These actions, which are accomplishedsimultaneously, will arrest the sink rate and place theairplane in the proper attitude for transition to aclimb. The initial target airspeed will be VY, or VX ifobstructions are present. With sufficient airspeed, theflaps should be retracted from full to an intermediateposition and the landing gear retracted when there isa positive rate of climb and no chance of runwaycontact. The remaining flaps should then beretracted. [Figure 12-10]

Figure 12-10. Go-around procedure.

Retract RemainingFlaps

Positive Rateof Climb, Retract

Gear, Climbat VY

500'Cruise Climb

Timely Decision toMake Go-Around Apply Max Power

Adjust Pitch Attitudeto Arrest Sink Rate

Flaps toIntermediate

Ch 12.qxd 5/7/04 9:54 AM Page 12-17

12-18

If the go-around was initiated due to conflicting trafficon the ground or aloft, the pilot should maneuver to theside, so as to keep the conflicting traffic in sight. Thismay involve a shallow bank turn to offset and then par-allel the runway/landing area.

If the airplane was in trim for the landing approachwhen the go-around was commenced, it will soon requirea great deal of forward elevator/stabilator pressure as theairplane accelerates away in a climb. The pilot shouldapply appropriate forward pressure to maintain thedesired pitch attitude. Trim should be commenced imme-diately. The “balked landing” checklist should bereviewed as work load permits.

Flaps should be retracted before the landing gear fortwo reasons. First, on most airplanes, full flaps producemore drag than the extended landing gear. Secondly,the airplane will tend to settle somewhat with flapretraction, and the landing gear should be down in theevent of an inadvertent, momentary touchdown.

Many multiengine airplanes have a landing gear retrac-tion speed significantly less than the extension speed.Care should be exercised during the go-around not toexceed the retraction speed. If the pilot desires toreturn for a landing, it is essential to re-accomplish theentire “before landing” checklist. An interruption to apilot’s habit patterns, such as a go-around, is a classicscenario for a subsequent gear up landing.

The preceding discussion of go-arounds assumes thatthe maneuver was initiated from normal approachspeeds or faster. If the go-around was initiated from alow airspeed, the initial pitch up to a climb attitude mustbe tempered with the necessity of maintaining adequateflying speed throughout the maneuver. Examples ofwhere this applies include go-arounds initiated from thelanding roundout or recovery from a bad bounce as wellas a go-around initiated due to an inadvertent approachto a stall. The first priority is always to maintain controland obtain adequate flying speed. A few moments oflevel or near level flight may be required as the airplaneaccelerates up to climb speed.

REJECTED TAKEOFFA takeoff can be rejected for the same reasons a takeoffin a single-engine airplane would be rejected. Once thedecision to reject a takeoff is made, the pilot shouldpromptly close both throttles and maintain directionalcontrol with the rudder, nosewheel steering, andbrakes. Aggressive use of rudder, nosewheel steering,and brakes may be required to keep the airplane onthe runway. Particularly, if an engine failure is notimmediately recognized and accompanied byprompt closure of both throttles. However, the pri-mary objective is not necessarily to stop the airplanein the shortest distance, but to maintain control ofthe airplane as it decelerates. In some situations, it

may be preferable to continue into the overrun areaunder control, rather than risk directional control loss,landing gear collapse, or tire/brake failure in anattempt to stop the airplane in the shortest possibledistance.

ENGINE FAILURE AFTER LIFT-OFFA takeoff or go-around is the most critical time to suf-fer an engine failure. The airplane will be slow, closeto the ground, and may even have landing gear andflaps extended. Altitude and time will be minimal.Until feathered, the propeller of the failed engine willbe windmilling, producing a great deal of drag andyawing tendency. Airplane climb performance will bemarginal or even non-existent, and obstructions maylie ahead. Add the element of surprise and the need fora plan of action before every takeoff is obvious.

With loss of an engine, it is paramount to maintainairplane control and comply with the manufacturer’srecommended emergency procedures. Complete fail-ure of one engine shortly after takeoff can be broadlycategorized into one of three following scenarios.

1. Landing gear down. [Figure 12-11] If theengine failure occurs prior to selecting the land-ing gear to the UP position, close both throttlesand land on the remaining runway or overrun.Depending upon how quickly the pilot reacts tothe sudden yaw, the airplane may run off theside of the runway by the time action is taken.There are really no other practical options. Asdiscussed earlier, the chances of maintainingdirectional control while retracting the flaps (ifextended), landing gear, feathering the propeller,and accelerating are minimal. On some airplaneswith a single-engine-driven hydraulic pump,failure of that engine means the only way toraise the landing gear is to allow the engine towindmill or to use a hand pump. This is not aviable alternative during takeoff.

2. Landing gear control selected up, single-engine climb performance inadequate.[Figure 12-12] When operating near or abovethe single-engine ceiling and an engine failure isexperienced shortly after lift-off, a landing mustbe accomplished on whatever essentially liesahead. There is also the option of continuingahead, in a descent at VYSE with the remainingengine producing power, as long as the pilotis not tempted to remain airborne beyond theairplane’s performance capability. Remainingairborne, bleeding off airspeed in a futileattempt to maintain altitude is almost invariablyfatal. Landing under control is paramount. Thegreatest hazard in a single-engine takeoff isattempting to fly when it is not within the per-

Ch 12.qxd 5/7/04 9:54 AM Page 12-18

12-19

formance capability of the airplane to do so. Anaccident is inevitable.

Analysis of engine failures on takeoff reveals a veryhigh success rate of off-airport engine inoperativelandings when the airplane is landed under control.Analysis also reveals a very high fatality rate in stall-spin accidents when the pilot attempts flight beyondthe performance capability of the airplane.

As mentioned previously, if the airplane’s landing gearretraction mechanism is dependent upon hydraulicpressure from a certain engine-driven pump, failureof that engine can mean a loss of hundreds of feet ofaltitude as the pilot either windmills the engine toprovide hydraulic pressure to raise the gear or raisesit manually with a backup pump.

3. Landing gear control selected up, single-engine climb performance adequate. [Figure12-13] If the single-engine rate of climb isadequate, the procedures for continued flightshould be followed. There are four areas ofconcern: control, configuration, climb, andchecklist.

• CONTROL— The first consideration followingengine failure during takeoff is control of the air-plane. Upon detecting an engine failure, aileronshould be used to bank the airplane and rudderpressure applied, aggressively if necessary, tocounteract the yaw and roll from asymmetricalthrust. The control forces, particularly on therudder, may be high. The pitch attitude for VYSEwill have to be lowered from that of VY.

Figure 12-11. Engine failure on takeoff, landing gear down.

If Engine Failure Occurs ator Before Lift-off, Abort theTakeoff.

If Failure of Engine Occurs After Lift-off:1. Maintain Directional Control2. Close Both Throttles

Figure 12-12. Engine failure on takeoff, inadequate climb performance.

Liftoff

Engine FailureDescend at VYSE

Land Under ControlOn or Off Runway

Over Run Area

Ch 12.qxd 5/7/04 9:54 AM Page 12-19

At least 5° of bank should be used, if necessary,to stop the yaw and maintain directional control.This initial bank input is held only momentarily,just long enough to establish or ensure direc-tional control. Climb performance suffers whenbank angles exceed approximately 2 or 3°, butobtaining and maintaining VYSE and directionalcontrol are paramount. Trim should be adjustedto lower the control forces.

• CONFIGURATION—The memory items fromthe “engine failure after takeoff” checklist[Figure 12-14] should be promptly executed toconfigure the airplane for climb. The specificprocedures to follow will be found in theAFM/POH and checklist for the particular air-plane. Most will direct the pilot to assume VYSE,set takeoff power, retract the flaps and landinggear, identify, verify, and feather the failedengine. (On some airplanes, the landing gear isto be retracted before the flaps.)

The “identify” step is for the pilot to initiallyidentify the failed engine. Confirmation on theengine gauges may or may not be possible,depending upon the failure mode. Identificationshould be primarily through the control inputsrequired to maintain straight flight, not theengine gauges. The “verify” step directs the pilotto retard the throttle of the engine thought to havefailed. No change in performance when the sus-pected throttle is retarded is verification that thecorrect engine has been identified as failed. Thecorresponding propeller control should bebrought fully aft to feather the engine.

• CLIMB—As soon as directional control is estab-lished and the airplane configured for climb, thebank angle should be reduced to that producingbest climb performance. Without specificguidance for zero sideslip, a bank of 2° andone-third to one-half ball deflection on theslip/skid indicator is suggested. VYSE is main-tained with pitch control. As turning flightreduces climb performance, climb should bemade straight ahead, or with shallow turns toavoid obstacles, to an altitude of at least 400feet AGL before attempting a return tothe airport.

Obstruction ClearanceAltitude or Above

At 500' or Obstruction Clearance Altitude:7. Engine Failure Checklist Circle and Land

3. Drag - Reduce - Gear, Flaps4. Identify - Inoperative Engine5. Verify - Inoperative Engine6. Feather - Inoperative Engine

If Failure of Engine Occurs After Liftoff:1. Maintain Directional Control - VYSE, Heading, Bank into Operating Engine2. Power - Increase or Set for Takeoff

Figure 12-13. Landing gear up—adequate climb performance.

Figure 12-14.Typical “engine failure after takeoff” emergencychecklist.

12-20

ENGINE FAILURE AFTER TAKEOFF

Airspeed . . . . . . . . . . . . . . . . . . . Maintain VYSE

Mixtures . . . . . . . . . . . . . . . . . . . RICHPropellers . . . . . . . . . . . . . . . . . .HIGH RPMThrottles . . . . . . . . . . . . . . . . . . . FULL POWERFlaps . . . . . . . . . . . . . . . . . . . . . . . UPLanding Gear . . . . . . . . . . . . . . . UPIdentify . . . . . . . . . . . . . . . . . . . . Determine failed

engineVerify Close throttle of

failed enginePropeller . . . . . . . . . . . . . . . . . . . FEATHERTrim Tabs . . . . . . . . . . . . . . . . . . . ADJUSTFailed Engine . . . . . . . . . . . . . . . SECUREAs soon as practical . . . . . . . . . . LAND

Bold - faced items require immediate action and are to be accomplished from memory.

. . . . . . . . . . . . . . . . . . . . . . . .

Ch 12.qxd 5/7/04 9:55 AM Page 12-20

12-21

• CHECKLIST—Having accomplished thememory items from the “engine failure aftertakeoff” checklist, the printed copy should bereviewed as time permits. The “securing failedengine” checklist [Figure 12-15] should then beaccomplished. Unless the pilot suspects anengine fire, the remaining items should beaccomplished deliberately and without unduehaste. Airplane control should never be sacrificedto execute the remaining checklists. The priorityitems have already been accomplished frommemory.

Figure 12-15. Typical “securing failed engine” emergencychecklist.

Other than closing the cowl flap of the failed engine,none of these items, if left undone, adversely affectsairplane climb performance. There is a distinct possibilityof actuating an incorrect switch or control if the proce-dure is rushed. The pilot should concentrate on flyingthe airplane and extracting maximum performance. IfATC facilities are available, an emergency should bedeclared.

The memory items in the “engine failure after takeoff”checklist may be redundant with the airplane’s existingconfiguration. For example, in the third takeoff scenario,the gear and flaps were assumed to already be retracted,yet the memory items included gear and flaps. This isnot an oversight. The purpose of the memory items isto either initiate the appropriate action or to confirmthat a condition exists. Action on each item may notbe required in all cases. The memory items alsoapply to more than one circumstance. In an enginefailure from a go-around, for example, the landinggear and flaps would likely be extended when thefailure occurred.

The three preceding takeoff scenarios all include thelanding gear as a key element in the decision to land orcontinue. With the landing gear selector in the DOWNposition, for example, continued takeoff and climb isnot recommended. This situation, however, is not jus-tification to retract the landing gear the moment theairplane lifts off the surface on takeoff as a normal

procedure. The landing gear should remain selecteddown as long as there is usable runway or overrunavailable to land on. The use of wing flaps for takeoffvirtually eliminates the likelihood of a single-engineclimb until the flaps are retracted.

There are two time-tested memory aids the pilot mayfind useful in dealing with engine-out scenarios. Thefirst, “Dead foot–dead engine” is used to assist in iden-tifying the failed engine. Depending on the failuremode, the pilot won’t be able to consistently identifythe failed engine in a timely manner from the enginegauges. In maintaining directional control, however,rudder pressure will be exerted on the side (left or right)of the airplane with the operating engine. Thus, the“dead foot” is on the same side as the “dead engine.”Variations on this saying include “Idle foot–idleengine” and “Working foot–working engine.”

The second memory aid has to do with climb perform-ance. The phrase “Raise the dead” is a reminder thatthe best climb performance is obtained with a veryshallow bank, about 2° toward the operating engine.Therefore, the inoperative, or “dead” engine should be“raised” with a very slight bank.

Not all engine power losses are complete failures.Sometimes the failure mode is such that partial powermay be available. If there is a performance loss whenthe throttle of the affected engine is retarded, the pilotshould consider allowing it to run until altitude and air-speed permit safe single-engine flight, if this can bedone without compromising safety. Attempts to save amalfunctioning engine can lead to a loss of the entireairplane.

ENGINE FAILURE DURING FLIGHTEngine failures well above the ground are handleddifferently than those occurring at lower speeds andaltitudes. Cruise airspeed allows better airplane con-trol, and altitude may permit time for a possiblediagnosis and remedy of the failure. Maintainingairplane control, however, is still paramount.Airplanes have been lost at altitude due to apparentfixation on the engine problem to the detriment offlying the airplane.

Not all engine failures or malfunctions are catastrophicin nature (catastrophic meaning a major mechanicalfailure that damages the engine and precludes furtherengine operation). Many cases of power loss arerelated to fuel starvation, where restoration of powermay be made with the selection of another tank. Anorderly inventory of gauges and switches may revealthe problem. Carburetor heat or alternate air can beselected. The affected engine may run smoothly on justone magneto or at a lower power setting. Altering the

SECURING FAILED ENGINE

Mixture . . . . . . . . . . . . . . . . . . . . . . . IDLE CUT OFFMagnetos . . . . . . . . . . . . . . . . . . . . . OFFAlternator . . . . . . . . . . . . . . . . . . . . . OFFCowl Flap . . . . . . . . . . . . . . . . . . . . . CLOSEBoost Pump . . . . . . . . . . . . . . . . . . . . OFFFuel Selector . . . . . . . . . . . . . . . . . . OFFProp Sync . . . . . . . . . . . . . . . . . . . . . OFFElectrical Load . . . . . . . . . . . . . . . . . . . ReduceCrossfeed . . . . . . . . . . . . . . . . . . . . . Consider

Ch 12.qxd 5/7/04 9:55 AM Page 12-21

12-22

mixture may help. If fuel vapor formation is suspected,fuel boost pump operation may be used to eliminateflow and pressure fluctuations.

Although it is a natural desire among pilots to save anailing engine with a precautionary shutdown, theengine should be left running if there is any doubt as toneeding it for further safe flight. Catastrophic failureaccompanied by heavy vibration, smoke, blisteringpaint, or large trails of oil, on the other hand, indicatea critical situation. The affected engine should befeathered and the “securing failed engine” checklistcompleted. The pilot should divert to the nearest suit-able airport and declare an emergency with ATC forpriority handling.

Fuel crossfeed is a method of getting fuel from a tankon one side of the airplane to an operating engine onthe other. Crossfeed is used for extended single-engineoperation. If a suitable airport is close at hand, there isno need to consider crossfeed. If prolonged flight on asingle-engine is inevitable due to airport non-avail-ability, then crossfeed allows use of fuel that wouldotherwise be unavailable to the operating engine. Italso permits the pilot to balance the fuel consumptionto avoid an out-of-balance wing heaviness.

AFM/POH procedures for crossfeed vary widely.Thorough fuel system knowledge is essential if cross-feed is to be conducted. Fuel selector positions and fuelboost pump usage for crossfeed differ greatly amongmultiengine airplanes. Prior to landing, crossfeedshould be terminated and the operating engine returnedto its main tank fuel supply.

If the airplane is above its single-engine absoluteceiling at the time of engine failure, it will slowlylose altitude. The pilot should maintain VYSE to min-imize the rate of altitude loss. This “drift down” ratewill be greatest immediately following the failureand will decrease as the single-engine ceiling isapproached. Due to performance variations causedby engine and propeller wear, turbulence, and pilottechnique, the airplane may not maintain altitudeeven at its published single-engine ceiling. Any furtherrate of sink, however, would likely be modest.

An engine failure in a descent or other low powersetting can be deceiving. The dramatic yaw and per-formance loss will be absent. At very low powersettings, the pilot may not even be aware of a failure.If a failure is suspected, the pilot should advance bothengine mixtures, propellers, and throttles significantly,to the takeoff settings if necessary, to correctly identifythe failed engine. The power on the operative enginecan always be reduced later.

ENGINE INOPERATIVE APPROACHAND LANDINGThe approach and landing with one engine inoperativeis essentially the same as a two-engine approach andlanding. The traffic pattern should be flown at similaraltitudes, airspeeds, and key positions as a two-engineapproach. The differences will be the reduced poweravailable and the fact that the remaining thrust isasymmetrical. A higher-than-normal power settingwill be necessary on the operative engine.

With adequate airspeed and performance, the landinggear can still be extended on the downwind leg. Inwhich case it should be confirmed DOWN no laterthan abeam the intended point of landing. Performancepermitting, initial extension of wing flaps (10°, typi-cally) and a descent from pattern altitude can also beinitiated on the downwind leg. The airspeed should beno slower than VYSE. The direction of the traffic pat-tern, and therefore the turns, is of no consequence asfar as airplane controllability and performance areconcerned. It is perfectly acceptable to make turnstoward the failed engine.

On the base leg, if performance is adequate, the flapsmay be extended to an intermediate setting (25°, typi-cally). If the performance is inadequate, as measuredby a decay in airspeed or high sink rate, delay furtherflap extension until closer to the runway. VYSE is stillthe minimum airspeed to maintain.

On final approach, a normal, 3° glidepath to a landingis desirable. VASI or other vertical path lighting aidsshould be utilized if available. Slightly steeperapproaches may be acceptable. However, a long, flat,low approach should be avoided. Large, sudden powerapplications or reductions should also be avoided.Maintain VYSE until the landing is assured, then slowto 1.3 VSO or the AFM/POH recommended speed. Thefinal flap setting may be delayed until the landing isassured, or the airplane may be landed with partialflaps.

The airplane should remain in trim throughout. Thepilot must be prepared, however, for a rudder trimchange as the power of the operating engine is reducedto idle in the roundout just prior to touchdown. Withdrag from only one windmilling propeller, the airplanewill tend to float more than on a two-engine approach.Precise airspeed control therefore is essential, especiallywhen landing on a short, wet and/or slippery surface.

Some pilots favor resetting the rudder trim to neutralon final and compensating for yaw by holding rudderpressure for the remainder of the approach. This elim-inates the rudder trim change close to the ground as

Ch 12.qxd 5/7/04 9:55 AM Page 12-22

the throttle is closed during the roundout for landing.This technique eliminates the need for groping for therudder trim and manipulating it to neutral during finalapproach, which many pilots find to be highly dis-tracting. AFM/POH recommendations or personalpreference should be used.

Single-engine go-arounds must be avoided. As a prac-tical matter in single-engine approaches, once the air-plane is on final approach with landing gear and flapsextended, it is committed to land. If not on the intendedrunway, then on another runway, a taxiway, or grassyinfield. The light-twin does not have the performanceto climb on one engine with landing gear and flapsextended. Considerable altitude will be lost whilemaintaining VYSE and retracting landing gear andflaps. Losses of 500 feet or more are not unusual. If thelanding gear has been lowered with an alternate meansof extension, retraction may not be possible, virtuallynegating any climb capability.

ENGINE INOPERATIVE FLIGHT PRINCIPLESBest single-engine climb performance is obtained atVYSE with maximum available power and minimumdrag. After the flaps and landing gear have beenretracted and the propeller of the failed engine feath-ered, a key element in best climb performance isminimizing sideslip.

With a single-engine airplane or a multiengine airplanewith both engines operative, sideslip is eliminatedwhen the ball of the turn and bank instrument is cen-tered. This is a condition of zero sideslip, and theairplane is presenting its smallest possible profile tothe relative wind. As a result, drag is at its minimum.Pilots know this as coordinated flight.

In a multiengine airplane with an inoperative engine,the centered ball is no longer the indicator of zerosideslip due to asymmetrical thrust. In fact, there is noinstrument at all that will directly tell the pilot theflight conditions for zero sideslip. In the absence of ayaw string, minimizing sideslip is a matter of placingthe airplane at a predetermined bank angle and ballposition. The AFM/POH performance charts for sin-gle-engine flight were determined at zero sideslip. Ifthis performance is even to be approximated, the zerosideslip technique must be utilized.

There are two different control inputs that can be usedto counteract the asymmetrical thrust of a failedengine: (1) yaw from the rudder, and (2) the horizontalcomponent of lift that results from bank with theailerons. Used individually, neither is correct. Usedtogether in the proper combination, zero sideslip andbest climb performance are achieved.

Three different scenarios of airplane control inputs arepresented below. Neither of the first two is correct.They are presented to illustrate the reasons for the zerosideslip approach to best climb performance.

1. Engine inoperative flight with wings level andball centered requires large rudder input towardsthe operative engine. [Figure 12-16] The result isa moderate sideslip towards the inoperativeengine. Climb performance will be reduced bythe moderate sideslip. With wings level, VMC willbe significantly higher than published as there isno horizontal component of lift available to helpthe rudder combat asymmetrical thrust.

Figure 12-16. Wings level engine-out flight.

Rudder Force

YawString

Fin EffectDue to Sideslip

Slipstream

Wings level, ball centered, airplane slips toward dead engine.Results: high drag, large control surface deflections required,and rudder and fin in opposition due to sideslip.

12-23

Ch 12.qxd 5/7/04 9:55 AM Page 12-23

2. Engine inoperative flight using ailerons alonerequires an 8 - 10° bank angle towards the oper-ative engine. [Figure 12-17] This assumes norudder input. The ball will be displaced welltowards the operative engine. The result is alarge sideslip towards the operative engine.Climb performance will be greatly reduced bythe large sideslip.

3. Rudder and ailerons used together in the propercombination will result in a bank of approxi-mately 2° towards the operative engine. Theball will be displaced approximately one-thirdto one-half towards the operative engine. The

result is zero sideslip and maximum climb per-formance. [Figure 12-18] Any attitude otherthan zero sideslip increases drag, decreasingperformance. VMC under these circumstanceswill be higher than published, as less than the5° bank certification limit is employed.

The precise condition of zero sideslip (bank angle andball position) varies slightly from model to model, andwith available power and airspeed. If the airplane isnot equipped with counter-rotating propellers, it willalso vary slightly with the engine failed due to P-factor.The foregoing zero sideslip recommendations apply to

YawString

Excess bank toward operating engine, no rudder input.Result: large sideslip toward operating engine and greatlyreduced climb performance.

12-24

Rudder Force

YawString

Bank toward operating engine, no sideslip. Results: muchlower drag and smaller control surface deflections.

Figure 12-17. Excessive bank engine-out flight. Figure 12-18. Zero sideslip engine-out flight.

Ch 12.qxd 5/7/04 9:55 AM Page 12-24

12-25

reciprocating engine multiengine airplanes flown atVYSE with the inoperative engine feathered. The zerosideslip ball position for straight flight is also the zerosideslip position for turning flight.

When bank angle is plotted against climb performancefor a hypothetical twin, zero sideslip results in the best(however marginal) climb performance or the least rateof descent. Zero bank (all rudder to counteract yaw)degrades climb performance as a result of moderatesideslip. Using bank angle alone (no rudder) severelydegrades climb performance as a result of a largesideslip.

The actual bank angle for zero sideslip varies amongairplanes from one and one-half to two and one-halfdegrees. The position of the ball varies from one-thirdto one-half of a ball width from instrument center.

For any multiengine airplane, zero sideslip can be con-firmed through the use of a yaw string. A yaw string isa piece of string or yarn approximately 18 to 36 inchesin length, taped to the base of the windshield, or to thenose near the windshield, along the airplane centerline.In two-engine coordinated flight, the relative wind willcause the string to align itself with the longitudinal axisof the airplane, and it will position itself straight up thecenter of the windshield. This is zero sideslip.Experimentation with slips and skids will vividly displaythe location of the relative wind. Adequate altitude andflying speed must be maintained while accomplishingthese maneuvers.

With an engine set to zero thrust (or feathered) and theairplane slowed to VYSE, a climb with maximum poweron the remaining engine will reveal the precise bankangle and ball deflection required for zero sideslip andbest climb performance. Zero sideslip will again beindicated by the yaw string when it aligns itself ver-tically on the windshield. There will be very minorchanges from this attitude depending upon theengine failed (with noncounter-rotating propellers),power available, airspeed and weight; but withoutmore sensitive testing equipment, these changes aredifficult to detect. The only significant differencewould be the pitch attitude required to maintain VYSEunder different density altitude, power available, andweight conditions.

If a yaw string is attached to the airplane at the timeof a VMC demonstration, it will be noted that VMCoccurs under conditions of sideslip. VMC was notdetermined under conditions of zero sideslip duringaircraft certification and zero sideslip is not part of aVMC demonstration for pilot certification.

To review, there are two different sets of bank anglesused in one-engine-inoperative flight.

• To maintain directional control of a multiengineairplane suffering an engine failure at low speeds(such as climb), momentarily bank at least 5°,and a maximum of 10° towards the operativeengine as the pitch attitude for VYSE is set. Thismaneuver should be instinctive to the proficientmultiengine pilot and take only 1 to 2 seconds toattain. It is held just long enough to assure direc-tional control as the pitch attitude for VYSE isassumed.

• To obtain the best climb performance, the air-plane must be flown at VYSE and zero sideslip,with the failed engine feathered and maximumavailable power from the operating engine. Zerosideslip is approximately 2° of bank toward theoperating engine and a one-third to one-half balldeflection, also toward the operating engine. Theprecise bank angle and ball position will varysomewhat with make and model and poweravailable. If above the airplane’s single-engineceiling, this attitude and configuration will resultin the minimum rate of sink.

In OEI flight at low altitudes and airspeeds such as theinitial climb after takeoff, pilots must operate the airplaneso as to guard against the three major accident factors:(1) loss of directional control, (2) loss of performance,and (3) loss of flying speed. All have equal potential tobe lethal. Loss of flying speed will not be a factor,however, when the airplane is operated with due regardfor directional control and performance.

SLOW FLIGHTThere is nothing unusual about maneuvering duringslow flight in a multiengine airplane. Slow flight maybe conducted in straight-and-level flight, turns, in theclean configuration, landing configuration, or at anyother combination of landing gear and flaps. Pilotsshould closely monitor cylinder head and oil temper-atures during slow flight. Some high performancemultiengine airplanes tend to heat up fairly quicklyunder some conditions of slow flight, particularly inthe landing configuration.

Simulated engine failures should not be conducted dur-ing slow flight. The airplane will be well below VSSEand very close to VMC. Stability, stall warning or stallavoidance devices should not be disabled whilemaneuvering during slow flight.

STALLSStall characteristics vary among multiengine airplanesjust as they do with single-engine airplanes, andtherefore, it is important to be familiar with them. Theapplication of power upon stall recovery, however,has a significantly greater effect during stalls in a

Ch 12.qxd 5/7/04 9:55 AM Page 12-25

12-26

twin than a single-engine airplane. In the twin, anapplication of power blows large masses of air fromthe propellers directly over the wings, producing asignificant amount of lift in addition to the expectedthrust. The multiengine airplane, particularly at lightoperating weights, typically has a higher thrust-to-weight ratio, making it quicker to accelerate out of astalled condition.

In general, stall recognition and recovery training intwins is performed similar to any high performancesingle-engine airplane. However, for twins, all stallmaneuvers should be planned so as to be completed atleast 3,000 feet AGL.

Single-engine stalls or stalls with significantly morepower on one engine than the other should not beattempted due to the likelihood of a departure fromcontrolled flight and possible spin entry. Similarly,simulated engine failures should not be performed dur-ing stall entry and recovery.

POWER-OFF STALLS (APPROACH AND LANDING)Power-off stalls are practiced to simulate typicalapproach and landing scenarios. To initiate a power-offstall maneuver, the area surrounding the airplaneshould first be cleared for possible traffic. The airplaneshould then be slowed and configured for an approachand landing. A stabilized descent should be established(approximately 500 f.p.m.) and trim adjusted. The pilotshould then transition smoothly from the stabilizeddescent attitude, to a pitch attitude that will induce astall. Power is reduced further during this phase, andtrimming should cease at speeds slower than takeoff.

When the airplane reaches a stalled condition, therecovery is accomplished by simultaneously reducingthe angle of attack with coordinated use of the flightcontrols and smoothly applying takeoff or specifiedpower. The flap setting should be reduced from full toapproach, or as recommended by the manufacturer.Then with a positive rate of climb, the landing gear isselected up. The remaining flaps are then retracted as aclimb has commenced. This recovery process shouldbe completed with a minimum loss of altitude, appro-priate to the aircraft characteristics.

The airplane should be accelerated to VX (if simulatedobstacles are present) or VY during recovery and climb.Considerable forward elevator/stabilator pressure willbe required after the stall recovery as the airplane accel-erates to VX or VY. Appropriate trim input should beanticipated.

Power-off stalls may be performed with wings level, orfrom shallow and medium banked turns. When recov-ering from a stall performed from turning flight, the

angle of attack should be reduced prior to leveling thewings. Flight control inputs should be coordinated.

It is usually not advisable to execute full stalls inmultiengine airplanes because of their relatively highwing loading. Stall training should be limited toapproaches to stalls and when a stall condition occurs.Recoveries should be initiated at the onset, or decay ofcontrol effectiveness, or when the first physicalindication of the stall occurs.

POWER-ON STALLS (TAKEOFF AND DEPARTURE)Power-on stalls are practiced to simulate typicaltakeoff scenarios. To initiate a power-on stallmaneuver, the area surrounding the airplane shouldalways be cleared to look for potential traffic. Theairplane is slowed to the manufacturer’s recommendedlift-off speed. The airplane should be configured in thetakeoff configuration. Trim should be adjusted for thisspeed. Engine power is then increased to that recom-mended in the AFM/POH for the practice of power-onstalls. In the absence of a recommended setting, useapproximately 65 percent of maximum availablepower while placing the airplane in a pitch attitude thatwill induce a stall. Other specified (reduced) powersettings may be used to simulate performance at highergross weights and density altitudes.

When the airplane reaches a stalled condition, therecovery is made by simultaneously lowering theangle of attack with coordinated use of the flightcontrols and applying power as appropriate.

However, if simulating limited power available forhigh gross weight and density altitude situations, thepower during the recovery should be limited to thatspecified. The recovery should be completed with aminimum loss of altitude, appropriate to aircraft char-acteristics.

The landing gear should be retracted when a positiverate of climb is attained, and flaps retracted, if flapswere set for takeoff. The target airspeed on recovery isVX if (simulated) obstructions are present, or VY. Thepilot should anticipate the need for nosedown trim asthe airplane accelerates to VX or VY after recovery.

Power-on stalls may be performed from straight flightor from shallow and medium banked turns. Whenrecovering from a power-on stall performed from turn-ing flight, the angle of attack should be reduced priorto leveling the wings, and the flight control inputsshould be coordinated.

SPIN AWARENESSNo multiengine airplane is approved for spins, andtheir spin recovery characteristics are generally very

Ch 12.qxd 5/7/04 9:55 AM Page 12-26

12-27

poor. It is therefore necessary to practice spin avoid-ance and maintain a high awareness of situations thatcan result in an inadvertent spin.

In order to spin any airplane, it must first be stalled. Atthe stall, a yawing moment must be introduced. In amultiengine airplane, the yawing moment may begenerated by rudder input or asymmetrical thrust. Itfollows, then, that spin awareness be at its greatestduring VMC demonstrations, stall practice, slowflight, or any condition of high asymmetrical thrust,particularly at low speed/high angle of attack. Single-engine stalls are not part of any multiengine trainingcurriculum.

A situation that may inadvertently degrade into a spinentry is a simulated engine failure introduced at aninappropriately low speed. No engine failure shouldever be introduced below safe, intentional one-engine-inoperative speed (VSSE). If no VSSE is published, useVYSE. The “necessity” of simulating engine failuresat low airspeeds is erroneous. Other than trainingsituations, the multiengine airplane is only operatedbelow VSSE for mere seconds just after lift-off orduring the last few dozen feet of altitude in preparationfor landing.

For spin avoidance when practicing engine failures,the flight instructor should pay strict attention to themaintenance of proper airspeed and bank angle as thestudent executes the appropriate procedure. Theinstructor should also be particularly alert during stalland slow flight practice. Forward center-of-gravitypositions result in favorable stall and spin avoidancecharacteristics, but do not eliminate the hazard.

When performing a VMC demonstration, the instructorshould also be alert for any sign of an impending stall.The student may be highly focused on the directionalcontrol aspect of the maneuver to the extent thatimpending stall indications go unnoticed. If a VMCdemonstration cannot be accomplished under existingconditions of density altitude, it may, for training pur-poses, be done utilizing the rudder blocking techniquedescribed in the following section.

As very few twins have ever been spin-tested (noneare required to), the recommended spin recoverytechniques are based only on the best informationavailable. The departure from controlled flight maybe quite abrupt and possibly disorienting. The direc-tion of an upright spin can be confirmed from the turnneedle or the symbolic airplane of the turn coordinator,if necessary. Do not rely on the ball position or otherinstruments.

If a spin is entered, most manufacturers recommendimmediately retarding both throttles to idle, applying

full rudder opposite the direction of rotation, andapplying full forward elevator/stabilator pressure (withailerons neutral). These actions should be taken as nearsimultaneously as possible. The controls should thenbe held in that position. Recovery, if possible, will takeconsiderable altitude. The longer the delay from entryuntil taking corrective action, the less likely that recov-ery will be successful.

ENGINE INOPERATIVE—LOSS OFDIRECTIONAL CONTROL DEMONSTRATIONAn engine inoperative—loss of directional controldemonstration, often referred to as a “VMC demon-stration,” is a required task on the practical test for amultiengine class rating. A thorough knowledge ofthe factors that affect VMC, as well as its definition,is essential for multiengine pilots, and as such anessential part of that required task. VMC is a speedestablished by the manufacturer, published in theAFM/POH, and marked on most airspeed indicatorswith a red radial line. The multiengine pilot mustunderstand that VMC is not a fixed airspeed under allconditions. VMC is a fixed airspeed only for the veryspecific set of circumstances under which it wasdetermined during aircraft certification. [Figure 12-19]

In reality, VMC varies with a variety of factors asoutlined below. The VMC noted in practice anddemonstration, or in actual single-engine operation,could be less or even greater than the publishedvalue, depending upon conditions and technique.

In aircraft certification, VMC is the sea level calibratedairspeed at which, when the critical engine is suddenlymade inoperative, it is possible to maintain control ofthe airplane with that engine still inoperative and thenmaintain straight flight at the same speed with an angleof bank of not more than 5°.

The foregoing refers to the determination of VMC under“dynamic” conditions. This technique is only used byhighly experienced flight test pilots during aircraft cer-tification. It is never to be attempted outside of thesecircumstances.

In aircraft certification, there is also a determination ofVMC under “static,” or steady-state conditions. If thereis a difference between the dynamic and static speeds,the higher of the two is published as VMC. The staticdetermination is simply the ability to maintain straightflight at VMC with a bank angle of not more than 5°. Thismore closely resembles the VMC demonstration requiredin the practical test for a multiengine class rating.

The AFM/POH-published VMC is determined with the“critical” engine inoperative. The critical engine is the

Ch 12.qxd 5/7/04 9:55 AM Page 12-27

12-28

engine whose failure has the most adverse effect ondirectional control. On twins with each engine rotatingin conventional, clockwise rotation as viewed from thepilot’s seat, the critical engine will be the left engine.

Multiengine airplanes are subject to P-factor just assingle-engine airplanes are. The descending propellerblade of each engine will produce greater thrust thanthe ascending blade when the airplane is operatedunder power and at positive angles of attack. Thedescending propeller blade of the right engine is alsoa greater distance from the center of gravity, andtherefore has a longer moment arm than the descend-ing propeller blade of the left engine. As a result,failure of the left engine will result in the mostasymmetrical thrust (adverse yaw) as the rightengine will be providing the remaining thrust.[Figure 12-19]

Many twins are designed with a counter-rotating rightengine. With this design, the degree of asymmetricalthrust is the same with either engine inoperative. Noengine is more critical than the other, and a VMCdemonstration may be performed with either enginewindmilling.

In aircraft certification, dynamic VMC is determinedunder the following conditions.

• Maximum available takeoff power. VMCincreases as power is increased on the operatingengine. With normally aspirated engines, VMC ishighest at takeoff power and sea level, anddecreases with altitude. With turbochargedengines, takeoff power, and therefore VMC,remains constant with increases in altitude up tothe engine’s critical altitude (the altitude where

the engine can no longer maintain 100 percentpower). Above the critical altitude, VMCdecreases just as it would with a normally aspi-rated engine, whose critical altitude is sea level.VMC tests are conducted at a variety of altitudes.The results of those tests are then extrapolated toa single, sea level value.

• Windmilling propeller. VMC increases withincreased drag on the inoperative engine. VMC ishighest, therefore, when the critical engine pro-peller is windmilling at the low pitch, highr.p.m. blade angle. VMC is determined with thecritical engine propeller windmilling in thetakeoff position, unless the engine is equippedwith an autofeather system.

• Most unfavorable weight and center-of-gravityposition. VMC increases as the center of gravityis moved aft. The moment arm of the rudder isreduced, and therefore its effectivity is reduced,as the center of gravity is moved aft. At the sametime, the moment arm of the propeller blade isincreased, aggravating asymmetrical thrust.Invariably, the aft-most CG limit is the mostunfavorable CG position. Currently, 14 CFRpart 23 calls for VMC to be determined at themost unfavorable weight. For twins certifi-cated under CAR 3 or early 14 CFR part 23,the weight at which VMC was determined wasnot specified. VMC increases as weight isreduced. [Figure 12-20]

• Landing gear retracted. VMC increases whenthe landing gear is retracted. Extended landinggear aids directional stability, which tends todecrease VMC.

Figure 12-19. Forces created during single-engine operation.

C L C L

D2D1

ArmArm

InoperativeEngine

InoperativeEngine

OperativeEngine

OperativeEngine

(Critical Engine)

Ch 12.qxd 5/7/04 9:55 AM Page 12-28

12-29

• Wing flaps in the takeoff position. For mosttwins, this will be 0° of flaps.

• Cowl flaps in the takeoff position.

• Airplane trimmed for takeoff.

• Airplane airborne and the ground effect negli-gible.

• Maximum of 5° angle of bank. VMC is highlysensitive to bank angle. To prevent claims ofan unrealistically low VMC speed in aircraftcertification, the manufacturer is permitted touse a maximum of a 5° bank angle toward theoperative engine. The horizontal component oflift generated by the bank assists the rudder incounteracting the asymmetrical thrust of theoperative engine. The bank angle works in themanufacturer’s favor in lowering VMC.

VMC is reduced significantly with increases in bankangle. Conversely, VMC increases significantly withdecreases in bank angle. Tests have shown that VMCmay increase more than 3 knots for each degree ofbank angle less than 5°. Loss of directional controlmay be experienced at speeds almost 20 knots abovepublished VMC when the wings are held level.

The 5° bank angle maximum is a regulatory limitimposed upon manufacturers in aircraft certification.The 5° bank does not inherently establish zero sideslipor best single-engine climb performance. Zero sideslip,and therefore best single-engine climb performance,occurs at bank angles significantly less than 5°. Thedetermination of VMC in certification is solely con-cerned with the minimum speed for directional controlunder a very specific set of circumstances, and has

nothing to do with climb performance, nor is it theoptimum airplane attitude or configuration for climbperformance.

During dynamic VMC determination in aircraft certi-fication, cuts of the critical engine using the mixturecontrol are performed by flight test pilots whilegradually reducing the speed with each attempt. VMCis the minimum speed at which directional controlcould be maintained within 20° of the original entryheading when a cut of the critical engine was made.During such tests, the climb angle with both enginesoperating was high, and the pitch attitude followingthe engine cut had to be quickly lowered to regainthe initial speed. Pilots should never attempt todemonstrate VMC with an engine cut from highpower, and never intentionally fail an engine atspeeds less than VSSE.

The actual demonstration of VMC and recovery in flighttraining more closely resembles static VMC determi-nation in aircraft certification. For a demonstration,the pilot should select an altitude that will allowcompletion of the maneuver at least 3,000 feet AGL.The following description assumes a twin withnoncounter-rotating engines, where the left engineis critical.

With the landing gear retracted and the flaps set to thetakeoff position, the airplane should be slowed toapproximately 10 knots above VSSE or VYSE(whichever is higher) and trimmed for takeoff. For theremainder of the maneuver, the trim setting should notbe altered. An entry heading should be selected andhigh r.p.m. set on both propeller controls. Power on theleft engine should be throttled back to idle as the rightengine power is advanced to the takeoff setting. Thelanding gear warning horn will sound as long as a

Figure 12-20. Effect of CG location on yaw.

A

B

InoperativeEngine

OperativeEngine

B x R = A x T

InoperativeEngine

OperativeEngine

A

R

B

R

T T

Ch 12.qxd 5/7/04 9:55 AM Page 12-29

12-30

throttle is retarded. The pilots should continue to care-fully listen, however, for the stall warning horn, if soequipped, or watch for the stall warning light. The leftyawing and rolling moment of the asymmetrical thrustis counteracted primarily with right rudder. A bankangle of 5° (a right bank, in this case) should also beestablished.

While maintaining entry heading, the pitch attitude isslowly increased to decelerate at a rate of 1 knot persecond (no faster). As the airplane slows and controleffectivity decays, the increasing yawing tendencyshould be counteracted with additional rudder pres-sure. Aileron displacement will also increase in orderto maintain 5° of bank. An airspeed is soon reachedwhere full right rudder travel and a 5° right bank canno longer counteract the asymmetrical thrust, and theairplane will begin to yaw uncontrollably to the left.

The moment the pilot first recognizes the uncontrol-lable yaw, or experiences any symptom associatedwith a stall, the operating engine throttle should besufficiently retarded to stop the yaw as the pitchattitude is decreased. Recovery is made with a minimumloss of altitude to straight flight on the entry heading atVSSE or VYSE, before setting symmetrical power. Therecovery should not be attempted by increasing poweron the windmilling engine alone.

To keep the foregoing description simple, there wereseveral important background details that were notcovered. The rudder pressure during the demonstrationcan be quite high. In certification, 150 pounds of forceis permitted before the limiting factor becomes rudderpressure, not rudder travel. Most twins will run out ofrudder travel long before 150 pounds of pressure isrequired. Still, it will seem considerable.

Maintaining altitude is not a criterion in accom-plishing this maneuver. This is a demonstration ofcontrollability, not performance. Many airplanes willlose (or gain) altitude during the demonstration. Beginthe maneuver at an altitude sufficient to allow completionby 3,000 feet AGL.

As discussed earlier, with normally aspirated engines,VMC decreases with altitude. Stalling speed (VS),however, remains the same. Except for a few models,published VMC is almost always higher than VS. Atsea level, there is usually a margin of several knotsbetween VMC and VS, but the margin decreases withaltitude, and at some altitude, VMC and VS are thesame. [Figure 12-21]

Should a stall occur while the airplane is under asym-metrical power, particularly high asymmetrical power,a spin entry is likely. The yawing moment inducedfrom asymmetrical thrust is little different from that

induced by full rudder in an intentional spin in theappropriate model of single-engine airplane. In thiscase, however, the airplane will depart controlledflight in the direction of the idle engine, not in thedirection of the applied rudder. Twins are not requiredto demonstrate recoveries from spins, and their spinrecovery characteristics are generally very poor.

Where VS is encountered at or before VMC, the depar-ture from controlled flight may be quite sudden, withstrong yawing and rolling tendencies to the invertedposition, and a spin entry. Therefore, during a VMCdemonstration, if there are any symptoms of animpending stall such as a stall warning light or horn,airframe or elevator buffet, or rapid decay in controleffectiveness, the maneuver should be terminatedimmediately, the angle of attack reduced as the throttleis retarded, and the airplane returned to the entryairspeed. It should be noted that if the pilots arewearing headsets, the sound of a stall warning hornwill tend to be masked.

The VMC demonstration only shows the earliest onsetof a loss of directional control. It is not a loss of con-trol of the airplane when performed in accordance withthe foregoing procedures. A stalled condition shouldnever be allowed to develop. Stalls should never beperformed with asymmetrical thrust and the VMCdemonstration should never be allowed to degrade intoa single-engine stall. A VMC demonstration that isallowed to degrade into a single-engine stall with highasymmetrical thrust is very likely to result in a loss ofcontrol of the airplane.

An actual demonstration of VMC may not be possibleunder certain conditions of density altitude, or withairplanes whose VMC is equal to or less than VS. Underthose circumstances, as a training technique, a demon-stration of VMC may be safely conducted by artificiallylimiting rudder travel to simulate maximum availablerudder. Limiting rudder travel should be accomplishedat a speed well above VS (approximately 20 knots).

Den

sity

Alti

tude

Indicated Airspeed

StallOccurs

First

YawOccurs First

RecoveryMay BeDifficult

Altitude WhereVMC = Stall Speed

Engine-OutPower-OnStall Speed (VS)

VMC

Figure 12-21. Graph depicting relationship of VMC to VS.

Ch 12.qxd 5/7/04 9:55 AM Page 12-30

The rudder limiting technique avoids the hazards ofspinning as a result of stalling with high asymmetricalpower, yet is effective in demonstrating the loss ofdirectional control.

The VMC demonstration should never be performedfrom a high pitch attitude with both engines operatingand then reducing power on one engine. The precedingdiscussion should also give ample warning as to whyengine failures are never to be performed at low air-speeds. An unfortunate number of airplanes and pilotshave been lost from unwarranted simulated enginefailures at low airspeeds that degenerated into loss ofcontrol of the airplane. VSSE is the minimum airspeedat which any engine failure should be simulated.

MULTIENGINE TRAINING CONSIDERATIONSFlight training in a multiengine airplane can be safelyaccomplished if both the instructor and the student arecognizant of the following factors.

• No flight should ever begin without a thoroughpreflight briefing of the objectives, maneuvers,expected student actions, and completion stan-dards.

• A clear understanding must be reached as to howsimulated emergencies will be introduced, andwhat action the student is expected to take.

The introduction, practice, and testing of emergencyprocedures has always been a sensitive subject.Surprising a multiengine student with an emergencywithout a thorough briefing beforehand has no placein flight training. Effective training must be carefullybalanced with safety considerations. Simulated enginefailures, for example, can very quickly become actualemergencies or lead to loss of the airplane whenapproached carelessly. Pulling circuit breakers canlead to a subsequent gear up landing. Stall-spin acci-dents in training for emergencies rival the number ofstall-spin accidents from actual emergencies.

All normal, abnormal, and emergency procedures canand should be introduced and practiced in the airplaneas it sits on the ground, power off. In this respect, theairplane is used as a cockpit procedures trainer (CPT),ground trainer, or simulator. The value of this trainingshould never be underestimated. The engines do nothave to be operating for real learning to occur. Uponcompletion of a training session, care should be takento return items such as switches, valves, trim, fuel selec-tors, and circuit breakers to their normal positions.

Pilots who do not use a checklist effectively will be ata significant disadvantage in multiengine airplanes.Use of the checklist is essential to safe operation of

airplanes and no flight should be conducted withoutone. The manufacturer’s checklist or an aftermarketchecklist for the specific make, model, and model yearshould be used. If there is a procedural discrepancybetween the checklist and AFM/POH, then theAFM/POH always takes precedence.

Certain immediate action items (such as the responseto an engine failure in a critical phase of flight) shouldbe committed to memory. After they are accomplished,and as work load permits, the pilot should verify theaction taken with a printed checklist.

Simulated engine failures during the takeoff groundroll should be accomplished with the mixture control.The simulated failure should be introduced at a speedno greater than 50 percent of VMC. If the student doesnot react promptly by retarding both throttles, theinstructor can always pull the other mixture.

The FAA recommends that all in-flight simulatedengine failures below 3,000 feet AGL be introducedwith a smooth reduction of the throttle. Thus, theengine is kept running and is available for instant use,if necessary. Throttle reduction should be smoothrather than abrupt to avoid abusing the engine and pos-sibly causing damage. All inflight engine failures mustbe conducted at VSSE or above.

If the engines are equipped with dynamic crankshaftcounterweights, it is essential to make throttle reductionsfor simulated failures smoothly. Other areas leading todynamic counterweight damage include high r.p.m. andlow manifold pressure combinations, overboosting, andpropeller feathering. Severe damage or repetitive abuseto counterweights will eventually lead to engine failure.Dynamic counterweights are found on larger, morecomplex engines—instructors should check withmaintenance personnel or the engine manufacturer todetermine if their engines are so equipped.

When an instructor simulates an engine failure, thestudent should respond with the appropriate memoryitems and retard the propeller control towards theFEATHER position. Assuming zero thrust will be set,the instructor should promptly move the propellercontrol forward and set the appropriate manifoldpressure and r.p.m. It is vital that the student be keptinformed of the instructor’s intentions. At this pointthe instructor may state words to the effect, “I have theright engine; you have the left. I have set zero thrustand the right engine is simulated feathered.” Thereshould never be any ambiguity as to who is operatingwhat systems or controls.

Following a simulated engine failure, the instructorshould continue to care for the “failed” engine just asthe student cares for the operative engine. If zero thrust

12-31

Ch 12.qxd 5/7/04 9:55 AM Page 12-31

12-32

is set to simulate a feathered propeller, the cowl flapshould be closed and the mixture leaned. An occasionalclearing of the engine is also desirable. If possible,avoid high power applications immediately followinga prolonged cool-down at a zero-thrust power setting.The flight instructor must impress on the student mul-tiengine pilot the critical importance of feathering thepropeller in a timely manner should an actual enginefailure situation be encountered. Awindmilling propeller,in many cases, has given the improperly trainedmultiengine pilot the mistaken perception that thefailed engine is still developing useful thrust, resultingin a psychological reluctance to feather, as featheringresults in the cessation of propeller rotation. The flightinstructor should spend ample time demonstratingthe difference in the performance capabilities of theairplane with a simulated feathered propeller (zerothrust) as opposed to a windmilling propeller.

All actual propeller feathering should be performed ataltitudes and positions where safe landings on estab-lished airports could be readily accomplished.Feathering and restart should be planned so as to becompleted no lower than 3,000 feet AGL. At certainelevations and with many popular multiengine trainingairplanes, this may be above the single-engine serviceceiling, and level flight will not be possible.

Repeated feathering and unfeathering is hard on theengine and airframe, and should be done only asabsolutely necessary to ensure adequate training. TheFAA’s practical test standards for a multiengine classrating requires the feathering and unfeathering of onepropeller during flight in airplanes in which it is safe todo so.

While much of this chapter has been devoted to theunique flight characteristics of the multiengine air-plane with one engine inoperative, the modern,well-maintained reciprocating engine is remarkablyreliable. Simulated engine failures at extremely lowaltitudes (such as immediately after lift-off) and/orbelow VSSE are undesirable in view of the non-existentsafety margins involved. The high risk of simulatingan engine failure below 200 feet AGL does not warrantpracticing such maneuvers.

For training in maneuvers that would be hazardous inflight, or for initial and recurrent qualification in anadvanced multiengine airplane, a simulator trainingcenter or manufacturer’s training course should be

given consideration. Comprehensive training manualsand classroom instruction are available along with sys-tem training aids, audio/visuals, and flight trainingdevices and simulators. Training under a wide varietyof environmental and aircraft conditions is availablethrough simulation. Emergency procedures that wouldbe either dangerous or impossible to accomplish in anairplane can be done safely and effectively in a flighttraining device or simulator. The flight training deviceor simulator need not necessarily duplicate the spe-cific make and model of airplane to be useful. Highlyeffective instruction can be obtained in trainingdevices for other makes and models as well as generictraining devices.

The majority of multiengine training is conducted infour to six-place airplanes at weights significantly lessthan maximum. Single-engine performance, particu-larly at low density altitudes, may be deceptively good.To experience the performance expected at higherweights, altitudes, and temperatures, the instructorshould occasionally artificially limit the amount ofmanifold pressure available on the operative engine.Airport operations above the single-engine ceiling canalso be simulated in this manner. Loading the airplanewith passengers to practice emergencies at maximumtakeoff weight is not appropriate.

The use of the touch-and-go landing and takeoff inflight training has always been somewhat controversial.The value of the learning experience must be weighedagainst the hazards of reconfiguring the airplane fortakeoff in an extremely limited time as well as the lossof the follow-through ordinarily experienced in a fullstop landing. Touch and goes are not recommendedduring initial aircraft familiarization in multiengineairplanes.

If touch and goes are to be performed at all, the studentand instructor responsibilities need to be carefullybriefed prior to each flight. Following touchdown, thestudent will ordinarily maintain directional controlwhile keeping the left hand on the yoke and the righthand on the throttles. The instructor resets the flapsand trim and announces when the airplane has beenreconfigured. The multiengine airplane needs consid-erably more runway to perform a touch and go than asingle-engine airplane. A full stop-taxi back landing ispreferable during initial familiarization. Solo touchand goes in twins are strongly discouraged.

Ch 12.qxd 5/7/04 9:55 AM Page 12-32

13-1

TAILWHEEL AIRPLANESTailwheel airplanes are often referred to as conventional gear airplanes. Due to their design andstructure, tailwheel airplanes exhibit operational andhandling characteristics that are different from those oftricycle gear airplanes. Tailwheel airplanes are not necessarily more difficult to takeoff, land, and/or taxithan tricycle gear airplanes; in fact under certain conditions, they may even handle with less difficulty.This chapter will focus on the operational differencesthat occur during ground operations, takeoffs, and landings.

LANDING GEARThe main landing gear forms the principal support ofthe airplane on the ground. The tailwheel also supportsthe airplane, but steering and directional control are itsprimary functions. With the tailwheel-type airplane, thetwo main struts are attached to the airplane slightlyahead of the airplane’s center of gravity (CG).

The rudder pedals are the primary directional controlswhile taxiing. Steering with the pedals may be accomplished through the forces of airflow or propellerslipstream acting on the rudder surface, or through amechanical linkage to the steerable tailwheel. Initially,the pilot should taxi with the heels of the feet resting onthe cockpit floor and the balls of the feet on the bottomof the rudder pedals. The feet should be slid up onto thebrake pedals only when it is necessary to depress thebrakes. This permits the simultaneous application ofrudder and brake whenever needed. Some models oftailwheel airplanes are equipped with heel brakes ratherthan toe brakes. In either configuration the brakes areused primarily to stop the airplane at a desired point, toslow the airplane, or as an aid in making a sharp controlled turn. Whenever used, they must be appliedsmoothly, evenly, and cautiously at all times.

TAXIINGWhen beginning to taxi, the brakes should be testedimmediately for proper operation. This is done by firstapplying power to start the airplane moving slowly forward, then retarding the throttle and simultaneouslyapplying pressure smoothly to both brakes. If brakingaction is unsatisfactory, the engine should be shut downimmediately.

To turn the airplane on the ground, the pilot shouldapply rudder in the desired direction of turn and usewhatever power or brake that is necessary to controlthe taxi speed. The rudder should be held in the direction of the turn until just short of the point wherethe turn is to be stopped, then the rudder pressurereleased or slight opposite pressure applied as needed.While taxiing, the pilot will have to anticipate themovements of the airplane and adjust rudder pressureaccordingly. Since the airplane will continue to turnslightly even as the rudder pressure is being released,the stopping of the turn must be anticipated and the rudder pedals neutralized before the desired heading isreached. In some cases, it may be necessary to applyopposite rudder to stop the turn, depending on the taxispeed.

The presence of moderate to strong headwinds and/or astrong propeller slipstream makes the use of the elevator necessary to maintain control of the pitch attitude while taxiing. This becomes apparent whenconsidering the lifting action that may be created onthe horizontal tail surfaces by either of those two factors. The elevator control should be held in the aftposition (stick or yoke back) to hold the tail down.

When taxiing in a quartering headwind, the wing onthe upwind side will usually tend to be lifted by thewind unless the aileron control is held in that direction(upwind aileron UP). Moving the aileron into the UPposition reduces the effect of wind striking that wing,thus reducing the lifting action. This control movementwill also cause the opposite aileron to be placed in theDOWN position, thus creating drag and possibly somelift on the downwind wing, further reducing the tendency of the upwind wing to rise.

When taxiing with a quartering tailwind, the elevatorshould be held in the full DOWN position (stick oryoke full forward), and the upwind aileron down. Sincethe wind is striking the airplane from behind, thesecontrol positions reduce the tendency of the wind to getunder the tail and the wing possibly causing the airplane to nose over. The application of these crosswind taxi corrections also helps to minimize theweathervaning tendency and ultimately results inincreased controllability.

Ch 13.qxd 5/7/04 10:04 AM Page 13-1

13-2

An airplane with a tailwheel has a tendency to weathervane or turn into the wind while it is being taxied. The tendency of the airplane to weathervane isgreatest while taxiing directly crosswind; consequently, directional control is somewhat difficult.Without brakes, it is almost impossible to keep the airplane from turning into any wind of considerablevelocity since the airplane’s rudder control capabilitymay be inadequate to counteract the crosswind. In taxiing downwind, the tendency to weathervane isincreased, due to the tailwind decreasing the effectiveness of the flight controls. This requires amore positive use of the rudder and the brakes, particularly if the wind velocity is above that of a lightbreeze.

Unless the field is soft, or very rough, it is best whentaxiing downwind to hold the elevator control in theforward position. Even on soft fields, the elevatorshould be raised only as much as is absolutely necessary to maintain a safe margin of control in casethere is a tendency of the airplane to nose over.

On most tailwheel-type airplanes, directional controlwhile taxiing is facilitated by the use of a steerable tailwheel, which operates along with the rudder. Thetailwheel steering mechanism remains engaged whenthe tailwheel is operated through an arc of about 16 to18° each side of neutral and then automaticallybecomes full swiveling when turned to a greater angle.On some models the tailwheel may also be locked inplace. The airplane may be pivoted within its ownlength, if desired, yet is fully steerable for slight turnswhile taxiing forward. While taxiing, the steerable tailwheel should be used for making normal turns andthe pilot’s feet kept off the brake pedals to avoid unnecessary wear on the brakes.

Since a tailwheel-type airplane rests on the tailwheelas well as the main landing wheels, it assumes a nose-high attitude when on the ground. In most casesthis places the engine cowling high enough to restrictthe pilot’s vision of the area directly ahead of the airplane. Consequently, objects directly ahead of theairplane are difficult, if not impossible, to see. Toobserve and avoid colliding with any objects or hazardous surface conditions, the pilot should alternately turn the nose from one side to the other—that is zigzag, or make a series of short S-turnswhile taxiing forward. This should be done slowly,smoothly, positively, and cautiously.

NORMAL TAKEOFF ROLLAfter taxiing onto the runway, the airplane should becarefully aligned with the intended takeoff direction,and the tailwheel positioned straight, or centered. Inairplanes equipped with a locking device, the tailwheelshould be locked in the centered position. After

releasing the brakes, the throttle should be smoothlyand continuously advanced to takeoff power. As theairplane starts to roll forward, the pilot should slideboth feet down on the rudder pedals so that the toes orballs of the feet are on the rudder portions, not on thebrake portions.

An abrupt application of power may cause the airplaneto yaw sharply to the left because of the torque effectsof the engine and propeller. Also, precession will beparticularly noticeable during takeoff in a tailwheel-type airplane if the tail is rapidly raised from a threepoint to a level flight attitude. The abrupt change ofattitude tilts the horizontal axis of the propeller, andthe resulting precession produces a forward force onthe right side (90° ahead in the direction of rotation),yawing the airplane’s nose to the left. The amount offorce created by this precession is directly related tothe rate the propeller axis is tilted when the tail israised. With this in mind, the throttle should always beadvanced smoothly and continuously to prevent anysudden swerving.

Smooth, gradual advancement of the throttle is veryimportant in tailwheel-type airplanes, since peculiarities in their takeoff characteristics are accentuated in proportion to how rapidly the takeoffpower is applied.

As speed is gained, the elevator control will tend toassume a neutral position if the airplane is correctlytrimmed. At the same time, directional control shouldbe maintained with smooth, prompt, positive ruddercorrections throughout the takeoff roll. The effects oftorque and P-factor at the initial speeds tend to pull thenose to the left. The pilot must use what rudder pressure is needed to correct for these effects or forexisting wind conditions to keep the nose of the airplane headed straight down the runway. The use ofbrakes for steering purposes should be avoided, sincethey will cause slower acceleration of the airplane’sspeed, lengthen the takeoff distance, and possiblyresult in severe swerving.

When the elevator trim is set for takeoff, on application of maximum allowable power, the airplanewill (when sufficient speed has been attained) normally assume the correct takeoff pitch attitude onits own—the tail will rise slightly. This attitude canthen be maintained by applying slight back-elevatorpressure. If the elevator control is pushed forward during the takeoff roll to prematurely raise the tail, itseffectiveness will rapidly build up as the speedincreases, making it necessary to apply back-elevatorpressure to lower the tail to the proper takeoff attitude.This erratic change in attitude will delay the takeoffand lead to directional control problems. Rudder pressure must be used promptly and smoothly to

Ch 13.qxd 5/7/04 10:04 AM Page 13-2

13-3

counteract yawing forces so that the airplane continuesstraight down the runway.

While the speed of the takeoff roll increases, more andmore pressure will be felt on the flight controls, particularly the elevators and rudder. Since the tail surfaces receive the full effect of the propeller slipstream, they become effective first. As the speedcontinues to increase, all of the flight controls willgradually become effective enough to maneuver theairplane about its three axes. It is at this point, in thetaxi to flight transition, that the airplane is being flownmore than taxied. As this occurs, progressively smallerrudder deflections are needed to maintain direction.

TAKEOFFSince a good takeoff depends on the proper takeoffattitude, it is important to know how this attitudeappears and how it is attained. The ideal takeoff attitude requires only minimum pitch adjustmentsshortly after the airplane lifts off to attain the speed forthe best rate of climb.

The tail should first be allowed to rise off the groundslightly to permit the airplane to accelerate more rapidly. At this point, the position of the nose in relation to the horizon should be noted, then elevatorpressure applied as necessary to hold this attitude. Thewings are kept level by applying aileron pressure asnecessary.

The airplane may be allowed to fly off the groundwhile in normal takeoff attitude. Forcing it into the airby applying excessive back-elevator pressure wouldresult in an excessively high pitch attitude and maydelay the takeoff. As discussed earlier, excessive andrapid changes in pitch attitude result in proportionatechanges in the effects of torque, making the airplanemore difficult to control.

Although the airplane can be forced into the air, this isconsidered an unsafe practice and should be avoidedunder normal circumstances. If the airplane is forcedto leave the ground by using too much back-elevatorpressure before adequate flying speed is attained, thewing’s angle of attack may be excessive, causing theairplane to settle back to the runway or even to stall.On the other hand, if sufficient back-elevator pressureis not held to maintain the correct takeoff attitude afterbecoming airborne, or the nose is allowed to lowerexcessively, the airplane may also settle back to therunway. This occurs because the angle of attack isdecreased and lift is diminished to the degree where itwill not support the airplane. It is important to hold theattitude constant after rotation or lift-off.

As the airplane leaves the ground, the pilot must continue to maintain straight flight, as well as holding

the proper pitch attitude. During takeoffs in strong,gusty wind, it is advisable that an extra margin of speedbe obtained before the airplane is allowed to leave theground. A takeoff at the normal takeoff speed mayresult in a lack of positive control, or a stall, when theairplane encounters a sudden lull in strong, gusty wind,or other turbulent air currents. In this case, the pilotshould hold the airplane on the ground longer to attainmore speed, then make a smooth, positive rotation toleave the ground.

CROSSWIND TAKEOFFIt is important to establish and maintain the properamount of crosswind correction prior to lift-off; that is,apply aileron pressure toward the wind to keep theupwind wing from rising and apply rudder pressure asneeded to prevent weathervaning.

As the tailwheel is raised off the runway, the holdingof aileron control into the wind may result in the downwind wing rising and the downwind main wheellifting off the runway first, with the remainder of thetakeoff roll being made on one main wheel. This isacceptable and is preferable to side-skipping.

If a significant crosswind exists, the main wheelsshould be held on the ground slightly longer than in anormal takeoff so that a smooth but definite lift-off canbe made. This procedure will allow the airplane toleave the ground under more positive control so that itwill definitely remain airborne while the properamount of drift correction is being established. Moreimportantly, it will avoid imposing excessive sideloads on the landing gear and prevent possible damagethat would result from the airplane settling back to therunway while drifting.

As both main wheels leave the runway, and groundfriction no longer resists drifting, the airplane will beslowly carried sideways with the wind until adequatedrift correction is maintained.

SHORT-FIELD TAKEOFFWing flaps should be lowered prior to takeoff if recommended by the manufacturer. Takeoff powershould be applied smoothly and continuously, (thereshould be no hesitation) to accelerate the airplane asrapidly as possible. As the takeoff roll progresses, theairplane’s pitch attitude and angle of attack should beadjusted to that which results in the minimum amountof drag and the quickest acceleration. The tail shouldbe allowed to rise off the ground slightly, then held inthis tail-low flight attitude until the proper lift-off orrotation airspeed is attained. For the steepest climb-outand best obstacle clearance, the airplane should beallowed to roll with its full weight on the main wheelsand accelerated to the lift-off speed.

Ch 13.qxd 5/7/04 10:04 AM Page 13-3

13-4

SOFT-FIELD TAKEOFFWing flaps may be lowered prior to starting the takeoff(if recommended by the manufacturer) to provide additional lift and transfer the airplane’s weight fromthe wheels to the wings as early as possible. The airplane should be taxied onto the takeoff surface without stopping on a soft surface. Stopping on a softsurface, such as mud or snow, might bog the airplane down. The airplane should be kept incontinuous motion with sufficient power while liningup for the takeoff roll.

As the airplane is aligned with the proposed takeoffpath, takeoff power is applied smoothly and as rapidlyas the powerplant will accept it without faltering. Thetail should be kept low to maintain the inherent positive angle of attack and to avoid any tendency ofthe airplane to nose over as a result of soft spots, tallgrass, or deep snow.

When the airplane is held at a nose-high attitudethroughout the takeoff run, the wings will, as speedincreases and lift develops, progressively relieve thewheels of more and more of the airplane’s weight,thereby minimizing the drag caused by surface irregularities or adhesion. If this attitude is accuratelymaintained, the airplane will virtually fly itself off theground. The airplane should be allowed to accelerateto climb speed in ground effect.

TOUCHDOWNThe touchdown is the gentle settling of the airplaneonto the landing surface. The roundout and touchdownshould be made with the engine idling, and the airplaneat minimum controllable airspeed, so that the airplanewill touch down at approximately stalling speed. Asthe airplane settles, the proper landing attitude must beattained by applying whatever back-elevator pressureis necessary. The roundout and touchdown should betimed so that the wheels of the main landing gear andtailwheel touch down simultaneously (three-pointlanding). This requires proper timing, technique, andjudgment of distance and altitude. [Figure 13-1]

When the wheels make contact with the ground, theelevator control should be carefully eased fully backto hold the tail down and to keep the tailwheel on theground. This provides more positive directional control of the airplane equipped with a steerable tailwheel, and prevents any tendency for the airplaneto nose over. If the tailwheel is not on the ground, easing back on the elevator control may cause the airplane to become airborne again because the changein attitude will increase the angle of attack and produce enough lift for the airplane to fly.

It is extremely important that the touchdown occurwith the airplane’s longitudinal axis exactly parallel tothe direction the airplane is moving along the runway.Failure to accomplish this not only imposes severeside loads on the landing gear, but imparts groundlooping (swerving) tendencies. To avoid theseside stresses or a ground loop, the pilot must neverallow the airplane to touch down while in a crab orwhile drifting.

AFTER-LANDING ROLLThe landing process must never be considered complete until the airplane decelerates to the normaltaxi speed during the landing roll or has been broughtto a complete stop when clear of the landing area. Thepilot must be alert for directional control difficultiesimmediately upon and after touchdown due to theground friction on the wheels. The friction creates apivot point on which a moment arm can act. This isbecause the CG is behind the main wheels. [Figure 13-2]

Any difference between the direction the airplane istraveling and the direction it is headed will produce amoment about the pivot point of the wheels, and theairplane will tend to swerve. Loss of directional control may lead to an aggravated, uncontrolled, tightturn on the ground, or a ground loop. The combinationof inertia acting on the CG and ground friction of themain wheels resisting it during the ground loop maycause the airplane to tip or lean enough for the outside

Main Gear and TailwheelTouch Down Simultaneously

Hold ElevatorFull Up

NormalGlide

Start Roundoutto Landing Attitude

Figure 13-1.Tailwheel touchdown.

Ch 13.qxd 5/7/04 10:04 AM Page 13-4

13-5

wingtip to contact the ground, and may even impose asideward force that could collapse the landing gear.The airplane can ground loop late in the after-landingroll because rudder effectiveness decreases with thedecreasing flow of air along the rudder surface as theairplane slows. As the airplane speed decreases and thetailwheel has been lowered to the ground, the steerabletailwheel provides more positive directional control.

To use the brakes, the pilot should slide the toes or feetup from the rudder pedals to the brake pedals (or applyheel pressure in airplanes equipped with heel brakes).If rudder pressure is being held at the time brakingaction is needed, that pressure should not be releasedas the feet or toes are being slid up to the brake pedals,because control may be lost before brakes can beapplied. During the ground roll, the airplane’s direction of movement may be changed by carefullyapplying pressure on one brake or uneven pressures oneach brake in the desired direction. Caution must beexercised, when applying brakes to avoid overcontrolling.

If a wing starts to rise, aileron control should beapplied toward that wing to lower it. The amountrequired will depend on speed because as the forwardspeed of the airplane decreases, the ailerons willbecome less effective.

The elevator control should be held back as far as possible and as firmly as possible, until the airplanestops. This provides more positive control with tailwheel steering, tends to shorten the after-landingroll, and prevents bouncing and skipping.

If available runway permits, the speed of the airplaneshould be allowed to dissipate in a normal manner by

the friction and drag of the wheels on the ground.Brakes may be used if needed to help slow the airplane.After the airplane has been slowed sufficiently and hasbeen turned onto a taxiway or clear of the landing area,it should be brought to a complete stop. Only after thisis done should the pilot retract the flaps and performother checklist items.

CROSSWIND LANDINGIf the crab method of drift correction has been usedthroughout the final approach and roundout, the crabmust be removed before touchdown by applying rudder to align the airplane’s longitudinal axis with itsdirection of movement. This requires timely and accurate action. Failure to accomplish this results insevere side loads being imposed on the landing gearand imparts ground looping tendencies.

If the wing-low method is used, the crosswind correction (aileron into the wind and opposite rudder)should be maintained throughout the roundout, and thetouchdown made on the upwind main wheel.

During gusty or high-wind conditions, prompt adjustments must be made in the crosswind correctionto assure that the airplane does not drift as it touchesdown.

As the forward speed decreases after initial contact,the weight of the airplane will cause the downwindmain wheel to gradually settle onto the runway.

An adequate amount of power should be used to maintain the proper airspeed throughout the approach,and the throttle should be retarded to idling positionafter the main wheels contact the landing surface. Caremust be exercised in closing the throttle before thepilot is ready for touchdown, because the sudden orpremature closing of the throttle may cause a suddenincrease in the descent rate that could result in a hardlanding.

CROSSWIND AFTER-LANDING ROLLParticularly during the after-landing roll, special attention must be given to maintaining directional control by the use of rudder and tailwheel steering,while keeping the upwind wing from rising by the useof aileron. Characteristically, an airplane has a greaterprofile, or side area, behind the main landing gear thanforward of it. [Figure 13-3] With the main wheels acting as a pivot point and the greater surface areaexposed to the crosswind behind that pivot point, theairplane will tend to turn or weathervane into the wind.This weathervaning tendency is more prevalent in thetailwheel-type because the airplane’s surface areabehind the main landing gear is greater than in nosewheel-type airplanes.

Point ofWheel Pivoting

C.G.

Figure 13-2. Effect of CG on directional control.

Ch 13.qxd 5/7/04 10:04 AM Page 13-5

13-6

Pilots should be familiar with the crosswind componentof each airplane they fly, and avoid operations inwind conditions that exceed the capability of the airplane, as well as their own limitations.

While the airplane is decelerating during the after-landing roll, more aileron must be applied to keepthe upwind wing from rising. Since the airplane isslowing down, there is less airflow around the aileronsand they become less effective. At the same time, therelative wind is becoming more of a crosswind andexerting a greater lifting force on the upwind wing.Consequently, when the airplane is coming to a stop,the aileron control must be held fully toward the wind.

WHEEL LANDINGLandings from power approaches in turbulence or incrosswinds should be such that the touchdown is madewith the airplane in approximately level flight attitude.The touchdown should be made smoothly on the mainwheels, with the tailwheel held clear of the runway.This is called a “wheel landing” and requires carefultiming and control usage to prevent bouncing. Thesewheel landings can be best accomplished by holdingthe airplane in level flight attitude until the mainwheels touch, then immediately but smoothly retarding the throttle, and holding sufficient forwardelevator pressure to hold the main wheels on theground. The airplane should never be forced onto theground by excessive forward pressure.

If the touchdown is made at too high a rate of descentas the main wheels strike the landing surface, the tail isforced down by its own weight. In turn, when the tail isforced down, the wing’s angle of attack increasesresulting in a sudden increase in lift and the airplanemay become airborne again. Then as the airplane’sspeed continues to decrease, the tail may again loweronto the runway. If the tail is allowed to settle tooquickly, the airplane may again become airborne. Thisprocess, often called “porpoising,” usually intensifieseven though the pilot tries to stop it. The best corrective action is to execute a go-around procedure.

SHORT-FIELD LANDINGUpon touchdown, the airplane should be firmly held ina three-point attitude. This will provide aerodynamicbraking by the wings. Immediately upon touchdown,and closing the throttle, the brakes should be appliedevenly and firmly to minimize the after-landing roll.The airplane should be stopped within the shortestpossible distance consistent with safety.

SOFT-FIELD LANDINGThe tailwheel should touch down simultaneously withor just before the main wheels, and should then be helddown by maintaining firm back-elevator pressurethroughout the landing roll. This will minimize anytendency for the airplane to nose over and will provideaerodynamic braking. The use of brakes on a soft fieldis not needed because the soft or rough surface itselfwill provide sufficient reduction in the airplane’s forward speed. Often it will be found that upon landing on a very soft field, the pilot will need toincrease power to keep the airplane moving and frombecoming stuck in the soft surface.

GROUND LOOPA ground loop is an uncontrolled turn during groundoperation that may occur while taxiing or taking off,but especially during the after-landing roll. It is notalways caused by drift or weathervaning, althoughthese things may cause the initial swerve. Careless useof the rudder, an uneven ground surface, or a soft spotthat retards one main wheel of the airplane may alsocause a swerve. In any case, the initial swerve tends tocause the airplane to ground loop.

Due to the characteristics of an airplane equipped witha tailwheel, the forces that cause a ground loopincrease as the swerve increases. The initial swervedevelops inertia and this, acting at the CG (which islocated behind the main wheels), swerves the airplaneeven more. If allowed to develop, the force producedmay become great enough to tip the airplane until onewing strikes the ground.

If the airplane touches down while drifting or in a crab,the pilot should apply aileron toward the high wingand stop the swerve with the rudder. Brakes should beused to correct for turns or swerves only when the rudder is inadequate. The pilot must exercise cautionwhen applying corrective brake action because it isvery easy to overcontrol and aggravate the situation. Ifbrakes are used, sufficient brake should be applied onthe low-wing wheel (outside of the turn) to stop theswerve. When the wings are approximately level, thenew direction must be maintained until the airplanehas slowed to taxi speed or has stopped.

Figure 13-3. Weathervaning tendency.

ProfileBehind Pivot Point

N

SW

E

Ch 13.qxd 5/7/04 10:04 AM Page 13-6

14-1

GENERALThe turbopropeller-powered airplane flies and handlesjust like any other airplane of comparable size andweight. The aerodynamics are the same. The majordifferences between flying a turboprop and othernon-turbine-powered airplanes are found in the power-plant and systems. The powerplant is different andrequires operating procedures that are unique to gasturbine engines. But so, too, are other systems such asthe electrical system, hydraulics, environmental, flightcontrol, rain and ice protection, and avionics. Theturbopropeller-powered airplane also has the advantageof being equipped with a constant speed, full featheringand reversing propeller—something normally notfound on piston-powered airplanes.

THE GAS TURBINE ENGINEBoth piston (reciprocating) engines and gas turbineengines are internal combustion engines. They have asimilar cycle of operation that consists of induction,compression, combustion, expansion, and exhaust. In apiston engine, each of these events is a separate distinctoccurrence in each cylinder. Also, in a piston engine anignition event must occur during each cycle, in each

cylinder. Unlike reciprocating engines, in gas turbineengines these phases of power occur simultaneouslyand continuously instead of one cycle at a time.Additionally, ignition occurs during the starting cycleand is continuous thereafter.

The basic gas turbine engine contains four sections:intake, compression, combustion, and exhaust.[Figure 14-1]

To start the engine, the compressor section is rotated byan electrical starter on small engines or an air drivenstarter on large engines. As compressor r.p.m.accelerates, air is brought in through the inlet duct,compressed to a high pressure, and delivered to thecombustion section (combustion chambers). Fuel isthen injected by a fuel controller through spraynozzles and ignited by igniter plugs. (Not all of thecompressed air is used to support combustion. Some ofthe compressed air bypasses the burner section and circu-lates within the engine to provide internal cooling.) Thefuel/air mixture in the combustion chamber is then burnedin a continuous combustion process and produces a veryhigh temperature, typically around 4,000°F, which heats

INTAKE COMPRESSION COMBUSTION EXHAUST

Air Inlet Compression Combustion Chambers Turbine Exhaust

Cold Section Hot Section

Figure 14-1. Basic components of a gas turbine engine.

Ch 14.qxd 5/7/04 10:08 AM Page 14-1

14-2

the entire air mass to 1,600 – 2,400°F. The mixture ofhot air and gases expands and is directed to the turbineblades forcing the turbine section to rotate, which inturn drives the compressor by means of a direct shaft.After powering the turbine section, the high velocityexcess exhaust exits the tail pipe or exhaust section.Once the turbine section is powered by gases from theburner section, the starter is disengaged, and theigniters are turned off. Combustion continues until theengine is shut down by turning off the fuel supply.

High-pressure exhaust gases can be used to providejet thrust as in a turbojet engine. Or, the gasescan be directed through an additional turbine to drive apropeller through reduction gearing, as in aturbopropeller (turboprop) engine.

TURBOPROP ENGINESThe turbojet engine excels the reciprocating engine intop speed and altitude performance. On the other hand,the turbojet engine has limited takeoff and initial climbperformance, as compared to that of a reciprocatingengine. In the matter of takeoff and initial climbperformance, the reciprocating engine is superior tothe turbojet engine. Turbojet engines are most efficientat high speeds and high altitudes, while propellers aremost efficient at slow and medium speeds (less than400 m.p.h.). Propellers also improve takeoff and climbperformance. The development of the turbopropengine was an attempt to combine in one engine thebest characteristics of both the turbojet, and propellerdriven reciprocating engine.

The turboprop engine offers several advantages overother types of engines such as:

• Light weight.

• Mechanical reliability due to relatively fewmoving parts.

• Simplicity of operation.

• Minimum vibration.

• High power per unit of weight.

• Use of propeller for takeoff and landing.

Turboprop engines are most efficient at speedsbetween 250 and 400 m.p.h. and altitudes between18,000 and 30,000 feet. They also perform well at theslow speeds required for takeoff and landing, and arefuel efficient. The minimum specific fuel consumptionof the turboprop engine is normally available in thealtitude range of 25,000 feet up to the tropopause.

The power output of a piston engine is measured inhorsepower and is determined primarily by r.p.m. andmanifold pressure. The power of a turboprop engine,however, is measured in shaft horsepower (shp). Shaft

horsepower is determined by the r.p.m. and the torque(twisting moment) applied to the propeller shaft. Sinceturboprop engines are gas turbine engines, some jetthrust is produced by exhaust leaving the engine. Thisthrust is added to the shaft horsepower to determinethe total engine power, or equivalent shaft horsepower(eshp). Jet thrust usually accounts for less than10 percent of the total engine power.

Although the turboprop engine is more complicatedand heavier than a turbojet engine of equivalent sizeand power, it will deliver more thrust at low subsonicairspeeds. However, the advantages decrease as flightspeed increases. In normal cruising speed ranges, thepropulsive efficiency (output divided by input) of aturboprop decreases as speed increases.

The propeller of a typical turboprop engine isresponsible for roughly 90 percent of the total thrustunder sea level conditions on a standard day. Theexcellent performance of a turboprop during takeoffand climb is the result of the ability of the propeller toaccelerate a large mass of air while the airplane ismoving at a relatively low ground and flight speed.“Turboprop,” however, should not be confused with“turbosupercharged” or similar terminology. Allturbine engines have a similarity to normally aspirated(non-supercharged) reciprocating engines in thatmaximum available power decreases almost as a directfunction of increased altitude.

Although power will decrease as the airplane climbsto higher altitudes, engine efficiency in terms ofspecific fuel consumption (expressed as pounds of fuelconsumed per horsepower per hour) will be increased.Decreased specific fuel consumption plus theincreased true airspeed at higher altitudes is a definiteadvantage of a turboprop engine.

All turbine engines, turboprop or turbojet, are definedby limiting temperatures, rotational speeds, and (in thecase of turboprops) torque. Depending on theinstallation, the primary parameter for power settingmight be temperature, torque, fuel flow or r.p.m.(either propeller r.p.m., gas generator (compressor)r.p.m. or both). In cold weather conditions, torquelimits can be exceeded while temperature limits arestill within acceptable range. While in hot weatherconditions, temperature limits may be exceededwithout exceeding torque limits. In any weather, themaximum power setting of a turbine engine is usuallyobtained with the throttles positioned somewhat aft ofthe full forward position. The transitioning pilot mustunderstand the importance of knowing and observinglimits on turbine engines. An overtemp or overtorquecondition that lasts for more than a very few secondscan literally destroy internal engine components.

Ch 14.qxd 5/7/04 10:08 AM Page 14-2

14-3

TURBOPROP ENGINE TYPES

FIXED SHAFTOne type of turboprop engine is the fixed shaftconstant speed type such as the Garrett TPE331.[Figure 14-2] In this type engine, ambient air isdirected to the compressor section through the engineinlet. An acceleration/diffusion process in the two-stage compressor increases air pressure and directs itrearward to a combustor. The combustor is made up ofa combustion chamber, a transition liner, and a turbineplenum. Atomized fuel is added to the air in thecombustion chamber. Air also surrounds thecombustion chamber to provide for cooling andinsulation of the combustor.

The gas mixture is initially ignited by high-energyigniter plugs, and the expanding combustion gasesflow to the turbine. The energy of the hot, highvelocity gases is converted to torque on the main shaftby the turbine rotors. The reduction gear converts thehigh r.p.m.—low torque of the main shaft to lowr.p.m.—high torque to drive the accessories and thepropeller. The spent gases leaving the turbine aredirected to the atmosphere by the exhaust pipe.

Only about 10 percent of the air which passes throughthe engine is actually used in the combustion process.Up to approximately 20 percent of the compressed airmay be bled off for the purpose of heating, cooling,cabin pressurization, and pneumatic systems. Over

half the engine power is devoted to driving thecompressor, and it is the compressor which canpotentially produce very high drag in the case of afailed, windmilling engine.

In the fixed shaft constant-speed engine, the enginer.p.m. may be varied within a narrow range of 96percent to 100 percent. During ground operation, ther.p.m. may be reduced to 70 percent. In flight, theengine operates at a constant speed, which ismaintained by the governing section of the propeller.Power changes are made by increasing fuel flow andpropeller blade angle rather than engine speed. Anincrease in fuel flow causes an increase in temperatureand a corresponding increase in energy available to theturbine. The turbine absorbs more energy andtransmits it to the propeller in the form of torque. Theincreased torque forces the propeller blade angle to beincreased to maintain the constant speed. Turbinetemperature is a very important factor to be consideredin power production. It is directly related to fuel flowand thus to the power produced. It must be limitedbecause of strength and durability of the material in thecombustion and turbine section. The control systemschedules fuel flow to produce specific temperaturesand to limit those temperatures so that the temperaturetolerances of the combustion and turbine sections arenot exceeded. The engine is designed to operate for itsentire life at 100 percent. All of its components, suchas compressors and turbines, are most efficient whenoperated at or near the r.p.m. design point.

PlanetaryReduction Gears

AirInlet

First-StageCentrifugal

Compressor

Second-StageCentrifugal

Compressor

Reverse-FlowAnnular Combustion

Chamber

Three-StageAxial Turbine

FuelNozzle

Igniter

ExhaustOutlet

Figure 14-2. Fixed shaft turboprop engine.

Ch 14.qxd 5/7/04 10:08 AM Page 14-3

14-4

Powerplant (engine and propeller) control is achievedby means of a power lever and a condition lever foreach engine. [Figure 14-3] There is no mixture controland/or r.p.m. lever as found on piston engine airplanes.On the fixed shaft constant-speed turboprop engine,the power lever is advanced or retarded to increase ordecrease forward thrust. The power lever is also usedto provide reverse thrust. The condition lever sets thedesired engine r.p.m. within a narrow range betweenthat appropriate for ground operations and flight.

Powerplant instrumentation in a fixed shaft turbopropengine typically consists of the following basicindicator. [Figure 14-4]

• Torque or horsepower.

• ITT – interturbine temperature.

• Fuel flow.

• RPM.

Torque developed by the turbine section is measuredby a torque sensor. The torque is then reflected on acockpit horsepower gauge calibrated in horsepowertimes 100. Interturbine temperature (ITT) is ameasurement of the combustion gas temperaturebetween the first and second stages of the turbinesection. The gauge is calibrated in degrees Celsius.Propeller r.p.m. is reflected on a cockpit tachometer asa percentage of maximum r.p.m. Normally, a vernierindicator on the gauge dial indicates r.p.m. in 1 percentgraduations as well. The fuel flow indicator indicatesfuel flow rate in pounds per hour.

Propeller feathering in a fixed shaft constant-speedturboprop engine is normally accomplished with thecondition lever. An engine failure in this type engine,however, will result in a serious drag condition due tothe large power requirements of the compressor beingabsorbed by the propeller. This could create a seriousairplane control problem in twin-engine airplanesunless the failure is recognized immediately and the

Power LeversCondition Levers

Figure 14-3. Powerplant controls—fixed shaft turboprop engine.

Figure 14-4. Powerplant instrumentation—fixed shaftturboprop engine.

Ch 14.qxd 5/7/04 10:09 AM Page 14-4

14-5

affected propeller feathered. For this reason, the fixedshaft turboprop engine is equipped with negativetorque sensing (NTS).

Negative torque sensing is a condition whereinpropeller torque drives the engine and the propeller isautomatically driven to high pitch to reduce drag. Thefunction of the negative torque sensing system is tolimit the torque the engine can extract from thepropeller during windmilling and thereby prevent largedrag forces on the airplane. The NTS system causes amovement of the propeller blades automaticallytoward their feathered position should the enginesuddenly lose power while in flight. The NTS systemis an emergency backup system in the event of suddenengine failure. It is not a substitution for the featheringdevice controlled by the condition lever.

SPLIT SHAFT/ FREE TURBINE ENGINEIn a free power-turbine engine, such as the Pratt &Whitney PT-6 engine, the propeller is driven by aseparate turbine through reduction gearing. Thepropeller is not on the same shaft as the basic engineturbine and compressor. [Figure 14-5] Unlike the fixedshaft engine, in the split shaft engine the propeller canbe feathered in flight or on the ground with the basicengine still running. The free power-turbine designallows the pilot to select a desired propeller governingr.p.m., regardless of basic engine r.p.m.

A typical free power-turbine engine has twoindependent counter-rotating turbines. One turbinedrives the compressor, while the other drives

the propeller through a reduction gearbox. Thecompressor in the basic engine consists of three axialflow compressor stages combined with a single cen-trifugal compressor stage. The axial and centrifugalstages are assembled on the same shaft, and operate asa single unit.

Inlet air enters the engine via a circular plenum nearthe rear of the engine, and flows forward through thesuccessive compressor stages. The flow is directedoutward by the centrifugal compressor stage throughradial diffusers before entering the combustionchamber, where the flow direction is actually reversed.The gases produced by combustion are once againreversed to expand forward through each turbine stage.After leaving the turbines, the gases are collected in aperipheral exhaust scroll, and are discharged to theatmosphere through two exhaust ports near the front ofthe engine.

A pneumatic fuel control system schedules fuel flow tomaintain the power set by the gas generator powerlever. Except in the beta range, propeller speed withinthe governing range remains constant at any selectedpropeller control lever position through the action of apropeller governor.

The accessory drive at the aft end of the engineprovides power to drive fuel pumps, fuel control, oilpumps, a starter/generator, and a tachometertransmitter. At this point, the speed of the drive (N1) isthe true speed of the compressor side of the engine,approximately 37,500 r.p.m.

ReductionGearbox

PropellerDrive Shaft Free (Power)

Turbine CompressorTurbine

(Gas Producer)

Three StageAxial Flow

Compressor

Exhaust Outlet

Air Inlet

CentrifugalCompressor

Igniter

Fuel Nozzle

Igniter

Fuel Nozzle

AccessoryGearbox

Figure 14-5. Split shaft/free turbine engine.

Ch 14.qxd 5/7/04 10:09 AM Page 14-5

14-6

Powerplant (engine and propeller) operation isachieved by three sets of controls for each engine: thepower lever, propeller lever, and condition lever.[Figure 14-6] The power lever serves to control enginepower in the range from idle through takeoff power.Forward or aft motion of the power lever increases ordecreases gas generator r.p.m. (N1) and therebyincreases or decreases engine power. The propellerlever is operated conventionally and controls theconstant-speed propellers through the primarygovernor. The propeller r.p.m. range is normally from1,500 to 1,900. The condition lever controls the flowof fuel to the engine. Like the mixture lever in apiston-powered airplane, the condition lever is locatedat the far right of the power quadrant. But the condi-tion lever on a turboprop engine is really just an on/offvalve for delivering fuel. There are HIGH IDLE andLOW IDLE positions for ground operations, but con-dition levers have no metering function. Leaning is notrequired in turbine engines; this function is performedautomatically by a dedicated fuel control unit.

Engine instruments in a split shaft/free turbine enginetypically consist of the following basic indicators.[Figure 14-7]

• ITT (interstage turbine temperature) indicator.

• Torquemeter.

• Propeller tachometer.

• N1 (gas generator) tachometer.

• Fuel flow indicator.

• Oil temperature/pressure indicator.

Figure 14-6. Powerplant controls—split shaft/free turbineengine.

Figure 14-7. Engine instruments—split shaft/free turbineengine.

Ch 14.qxd 5/7/04 10:09 AM Page 14-6

14-7

The ITT indicator gives an instantaneous reading ofengine gas temperature between the compressorturbine and the power turbines. The torquemeterresponds to power lever movement and gives anindication, in foot-pounds (ft/lb), of the torque beingapplied to the propeller. Because in the free turbineengine, the propeller is not attached physically to theshaft of the gas turbine engine, two tachometers arejustified—one for the propeller and one for the gasgenerator. The propeller tachometer is read directly inrevolutions per minute. The N1 or gas generator is readin percent of r.p.m. In the Pratt & Whitney PT-6engine, it is based on a figure of 37,000 r.p.m. at 100percent. Maximum continuous gas generator is limitedto 38,100 r.p.m. or 101.5 percent N1.

The ITT indicator and torquemeter are used to settakeoff power. Climb and cruise power are establishedwith the torquemeter and propeller tachometer whileobserving ITT limits. Gas generator (N1) operation ismonitored by the gas generator tachometer. Properobservation and interpretation of these instrumentsprovide an indication of engine performanceand condition.

REVERSE THRUST AND BETA RANGEOPERATIONSThe thrust that a propeller provides is a function of theangle of attack at which the air strikes the blades, andthe speed at which this occurs. The angle of attackvaries with the pitch angle of the propeller.

So called “flat pitch” is the blade position offeringminimum resistance to rotation and no net thrust formoving the airplane. Forward pitch produces forwardthrust—higher pitch angles being required at higherairplane speeds.

The “feathered” position is the highest pitch angleobtainable. [Figure 14-8] The feathered positionproduces no forward thrust. The propeller is generallyplaced in feather only in case of in-flight engine failureto minimize drag and prevent the air from using thepropeller as a turbine.

In the “reverse” pitch position, the engine/propellerturns in the same direction as in the normal (forward)pitch position, but the propeller blade angle ispositioned to the other side of flat pitch. [Figure 14-8]In reverse pitch, air is pushed away from the airplanerather than being drawn over it. Reverse pitch resultsin braking action, rather than forward thrust of the air-plane. It is used for backing away from obstacles whentaxiing, controlling taxi speed, or to aid in bringing theairplane to a stop during the landing roll. Reverse pitchdoes not mean reverse rotation of the engine. Theengine delivers power just the same, no matter whichside of flat pitch the propeller blades are positioned.

With a turboprop engine, in order to obtain enoughpower for flight, the power lever is placed somewherebetween flight idle (in some engines referred to as“high idle”) and maximum. The power lever directssignals to a fuel control unit to manually select fuel.The propeller governor selects the propeller pitchneeded to keep the propeller/engine on speed. This isreferred to as the propeller governing or “alpha” modeof operation. When positioned aft of flight idle, how-ever, the power lever directly controls propeller bladeangle. This is known as the “beta” range of operation.

The beta range of operation consists of power leverpositions from flight idle to maximum reverse.

Power Prop Condition

Reverse

Beta

Idle

FeatherNormal

"Forward" Pitch

Feather"Maximum Forward

Pitch"

Flat Pitch

Reverse Pitch

FuelCutOff

Reverse

FuelCutOff

Reverse Feather

FuelCutOff

Feather

FuelCutOff

LowIdle

FltIdle

LowIdle

FltIdle

LowIdle

FltIdle

LowIdle

FltIdle

PullUp

Figure 14-8. Propeller pitch angle characteristics.

Ch 14.qxd 5/7/04 10:09 AM Page 14-7

14-8

Beginning at power lever positions just aft of flightidle, propeller blade pitch angles become progressivelyflatter with aft movement of the power lever until theygo beyond maximum flat pitch and into negative pitch,resulting in reverse thrust. While in a fixed shaft/constant-speed engine, the engine speed remainslargely unchanged as the propeller blade anglesachieve their negative values. On the split shaft PT-6engine, as the negative 5° position is reached, furtheraft movement of the power lever will also result in aprogressive increase in engine (N1) r.p.m. until amaximum value of about negative 11° of blade angleand 85 percent N1 are achieved.

Operating in the beta range and/or with reverse thrustrequires specific techniques and procedures dependingon the particular airplane make and model. There arealso specific engine parameters and limitations foroperations within this area that must be adhered to. Itis essential that a pilot transitioning to turbopropairplanes become knowledgeable and proficient inthese areas, which are unique to turbine-engine-powered airplanes.

TURBOPROP AIRPLANE ELECTRICALSYSTEMSThe typical turboprop airplane electrical system is a28-volt direct current (DC) system, which receivespower from one or more batteries and a starter/generator for each engine. The batteries may either beof the lead-acid type commonly used on piston-powered airplanes, or they may be of thenickel-cadmium (NiCad) type. The NiCad batterydiffers from the lead-acid type in that its outputremains at relatively high power levels for longerperiods of time. When the NiCad battery is depleted,however, its voltage drops off very suddenly. Whenthis occurs, its ability to turn the compressor for enginestart is greatly diminished and the possibility of enginedamage due to a hot start increases. Therefore, it isessential to check the battery’s condition before everyengine start. Compared to lead-acid batteries, high-performance NiCad batteries can be recharged veryquickly. But the faster the battery is recharged, themore heat it produces. Therefore, NiCad batteryequipped airplanes are fitted with battery overheatannunciator lights signifying maximum safe andcritical temperature thresholds.

The DC generators used in turboprop airplanes doubleas starter motors and are called “starter/generators.”The starter/generator uses electrical power to producemechanical torque to start the engine and then uses theengine’s mechanical torque to produce electrical powerafter the engine is running. Some of the DC powerproduced is changed to 28 volt 400 cycle alternatingcurrent (AC) power for certain avionic, lighting,and indicator synchronization functions. This is

accomplished by an electrical component called aninverter.

The distribution of DC and AC power throughout thesystem is accomplished through the use of power dis-tribution buses. These “buses” as they are called areactually common terminals from which individualelectrical circuits get their power. [Figure 14-9]

Buses are usually named for what they power (avion-ics bus, for example), or for where they get their power(right generator bus, battery bus). The distribution ofDC and AC power is often divided into functionalgroups (buses) that give priority to certain equipment

5 GEAR WARN

5 TRIM INDICATOR

3 TRIM ELEVATOR

5 TRIM AILERON

5 STALL WARNING

5 ACFT ANN-1

5 L TURN & BANK

5 TEMP OVRD

5 HP EMER L & R

5 FUEL QUANTITY

5 L ENGINE GAUGE

5 R ENGINE GAUGE

5 MISC ELEC

5 LDG LT MOTOR

5 BLEED L

3 WSHLD L

3 LIGHTS AUX

5 FUEL FLOW

PO

WE

R D

IST

RIB

UT

ION

BU

S

Figure 14-9.Typical individual power distribution bus.

Ch 14.qxd 5/7/04 10:09 AM Page 14-8

14-9

during normal and emergency operations. Main busesserve most of the airplane’s electrical equipment.Essential buses feed power to equipment having toppriority. [Figure 14-10]

Multiengine turboprop airplanes normally haveseveral power sources—a battery and at least onegenerator per engine. The electrical systems areusually designed so that any bus can be energized byany of the power sources. For example, a typicalsystem might have a right and left generator busespowered normally by the right and left engine-drivengenerators. These buses will be connected by anormally open switch, which isolates them from eachother. If one generator fails, power will be lost to its

bus, but power can be restored to that bus by closing abus tie switch. Closing this switch connects the busesand allows the operating generator to power both.

Power distribution buses are protected from shortcircuits and other malfunctions by a type of fuse calleda current limiter. In the case of excessive currentsupplied by any power source, the current limiter willopen the circuit and thereby isolate that power sourceand allow the affected bus to become separated fromthe system. The other buses will continue to operatenormally. Individual electrical components areconnected to the buses through circuit breakers. Acircuit breaker is a device which opens an electricalcircuit when an excess amount of current flows.

PRIMARYINVERTER

SECONDARYINVERTER

LEFTMAINBUS

RIGHTMAINBUS

LEFTESSENTIAL

BUS

RIGHTESSENTIAL

BUS

AMPS0

100

200

300

400 DCVOLTS

0

28

35AMPS

0

100

200

300

400

REGULATOR REGULATORLEFT

GENERATORBUS

BATTERYCHARGING

BUS

RIGHTGENERATOR

BUS

LEFTGENERATOR/

STARTER

LEFTGENERATOR/

STARTER

G.P.U.

LEFTBATTERY

RIGHTBATTERY

OVERVOLTAGECUTOUT

Current Limiter

Circuit Breaker

Bus

Figure 14-10. Simplified schematic of turboprop airplane electrical system.

Ch 14.qxd 5/7/04 10:09 AM Page 14-9

14-10

OPERATIONAL CONSIDERATIONSAs previously stated, a turboprop airplane flies just likeany other piston engine airplane of comparable sizeand weight. It is in the operation of the engines andairplane systems that makes the turboprop airplanedifferent from its piston engine counterpart. Piloterrors in engine and/or systems operation are the mostcommon cause of aircraft damage or mishap. The timeof maximum vulnerability to pilot error in any gasturbine engine is during the engine start sequence.

Turbine engines are extremely heat sensitive. Theycannot tolerate an overtemperature condition for morethan a very few seconds without serious damage beingdone. Engine temperatures get hotter during startingthan at any other time. Thus, turbine engines haveminimum rotational speeds for introducing fuel intothe combustion chambers during startup. Hyper-vigilant temperature and acceleration monitoring onthe part of the pilot remain crucial until the engine isrunning at a stable speed. Successful engine startingdepends on assuring the correct minimum batteryvoltage before initiating start, or employing a ground

power unit (GPU) of adequate output.

After fuel is introduced to the combustion chamberduring the start sequence, “light-off” and its associatedheat rise occur very quickly. Engine temperatures mayapproach the maximum in a matter of 2 or 3 secondsbefore the engine stabilizes and temperatures fall intothe normal operating range. During this time, the pilotmust watch for any tendency of the temperatures toexceed limitations and be prepared to cut off fuel tothe engine.

An engine tendency to exceed maximum startingtemperature limits is termed a hot start. The tempera-ture rise may be preceded by unusually high initial fuelflow, which may be the first indication the pilot hasthat the engine start is not proceeding normally.Serious engine damage will occur if the hot start isallowed to continue.

A condition where the engine is accelerating moreslowly than normal is termed a hung start or falsestart. During a hung start/false start, the engine may

1. Before Takeoff Checks – Completed

2. Lineup Checks – Completed Heading Bug – Runway Heading Command Bars – 10 Degrees Up

3. Power – Set 850 ITT / 650 HP Max: 923 ITT / 717.5 HP

7. Ign Ovrd – Off

6. Gear Up

8. After T/O Checklist Yaw Damp – On

9. Climb Power – Set 850 ITT / 650 HP 98 – 99% RPM

11. Climb Speed – Set Climb Checks – Completed

10. Prop Sync – On

These are merely typical procedures. The pilot maintains his or her prerogative to modify configuration and airspeeds as required by existing conditions, as long as compliance with the FAA approved Airplane Flight Manual is assured.

NOTE:

5. Rotate at 96 – 100 KIAS

4. Annunciators – Check Engine Inst. – Check

PRESSUREALTITUDE

FT

Sea Level

CLIMBSPEEDKIAS

139139134128123118113112

5,00010,00015,00020,00025,00030,00031,000

12. Cruise Checks – Completed

Figure 14-11. Example—typical turboprop airplane takeoff and departure profile.

Ch 14.qxd 5/7/04 10:09 AM Page 14-10

14-11

stabilize at an engine r.p.m. that is not high enough forthe engine to continue to run without help from thestarter. This is usually the result of low battery poweror the starter not turning the engine fast enough for itto start properly.

Takeoffs in turboprop airplanes are not made byautomatically pushing the power lever full forward tothe stops. Depending on conditions, takeoff power maybe limited by either torque or by engine temperature.Normally, the power lever position on takeoff will besomewhat aft of full forward.

Takeoff and departure in a turboprop airplane(especially a twin-engine cabin-class airplane) shouldbe accomplished in accordance with a standard takeoffand departure “profile” developed for the particularmake and model. [Figure 14-11] The takeoff anddeparture profile should be in accordance with theairplane manufacturer’s recommended procedures asoutlined in the FAA-approved Airplane Flight Manualand/or the Pilot’s Operating Handbook (AFM/POH).The increased complexity of turboprop airplanesmakes the standardization of procedures a necessityfor safe and efficient operation. The transitioning pilotshould review the profile procedures before eachtakeoff to form a mental picture of the takeoff anddeparture process.

For any given high horsepower operation, the pilot canexpect that the engine temperature will climb asaltitude increases at a constant power. On a warm orhot day, maximum temperature limits may be reachedat a rather low altitude, making it impossible tomaintain high horsepower to higher altitudes. Also, theengine’s compressor section has to work harder withdecreased air density. Power capability is reduced byhigh-density altitude and power use may have to bemodulated to keep engine temperature within limits.

In a turboprop airplane, the pilot can close thethrottles(s) at any time without concern for cooling theengine too rapidly. Consequently, rapid descents withthe propellers in low pitch can be dramatically steep.Like takeoffs and departures, approach and landingshould be accomplished in accordance with a standardapproach and landing profile. [Figure 14-12]

A stabilized approach is an essential part of theapproach and landing process. In a stabilized approach,the airplane, depending on design and type, is placedin a stabilized descent on a glidepath ranging from 2.5to 3.5°. The speed is stabilized at some reference fromthe AFM/POH—usually 1.25 to 1.30 times the stallspeed in approach configuration. The descent rate isstabilized from 500 feet per minute to 700 feet perminute until the landing flare.

2. Arrival 160 KIAS 250 HP Level Flt – Clean Config.

3. Begin Before Landing Checklist

7. Final 120 KIAS Flaps – As Desired

6. Base Before Landing Checklist 120 – 130 KIAS

8. Short Final 110 KIAS Gear – Recheck Down

9. Threshold 96 – 100 KIAS

11. After Landing Checklist10. Landing Cond. Levers – Keep Full Fwd. Power – Beta/Reverse

These are merely typical procedures. The pilot maintains his or her prerogative to modify configuration and airspeeds as required by existing conditions, as long as compliance with the FAA approved Airplane Flight Manual is assured.

NOTE:

5. 130 – 140 KIAS

4. Midfield Downwind 140 – 160 KIAS 250 HP Gear – Down Flaps – Half

1. Leaving Cruise Altitude Descent/Approach Checklist

Figure 14-12. Example—typical turboprop airplane arrival and landing profile.

Ch 14.qxd 5/7/04 10:09 AM Page 14-11

14-12

Landing some turboprop airplanes (as well as somepiston twins) can result in a hard, prematuretouchdown if the engines are idled too soon. This isbecause large propellers spinning rapidly in low pitchcreate considerable drag. In such airplanes, it may bepreferable to maintain power throughout the landingflare and touchdown. Once firmly on the ground,propeller beta range operation will dramatically reducethe need for braking in comparison to piston airplanesof similar weights.

TRAINING CONSIDERATIONSThe medium and high altitudes at which turbopropairplanes are flown provide an entirely differentenvironment in terms of regulatory requirements,airspace structure, physiological requirements, andeven meteorology. The pilot transitioning to turbopropairplanes, particularly those who are not familiar withoperations in the high/medium altitude environment,should approach turboprop transition training with thisin mind. Thorough ground training should cover allaspects of high/medium altitude flight, including theflight environment, weather, flight planning andnavigation, physiological aspects of high-altitudeflight, oxygen and pressurization system operation,and high-altitude emergencies.

Flight training should prepare the pilot to demonstratea comprehensive knowledge of airplane performance,systems, emergency procedures, and operatinglimitations, along with a high degree of proficiency inperforming all flight maneuvers and in-flightemergency procedures.

The training outline below covers the minimuminformation needed by pilots to operate safely at highaltitudes.

a. Ground Training(1) The High-Altitude Flight Environment

(a) Airspace(b) Title 14 of the Code of Federal Regulations

(14 CFR) section 91.211, requirements foruse of supplemental oxygen

(2) Weather(a) The atmosphere(b) Winds and clear air turbulence(c) Icing

(3) Flight Planning and Navigation(a) Flight planning(b) Weather charts(c) Navigation(d) Navaids

(4) Physiological Training(a) Respiration(b) Hypoxia(c) Effects of prolonged oxygen use(d) Decompression sickness(e) Vision(f) Altitude chamber (optional)

(5) High-Altitude Systems and Components(a) Oxygen and oxygen equipment(b) Pressurization systems(c) High-altitude components

(6) Aerodynamics and Performance Factors(a) Acceleration(b) G-forces(c) MACH Tuck and MACH Critical (turbojet

airplanes)(7) Emergencies

(a) Decompression(b) Donning of oxygen masks(c) Failure of oxygen mask, or complete loss of

oxygen supply/system(d) In-flight fire(e) Flight into severe turbulence or thunder-

storms

b. Flight Training(1) Preflight Briefing(2) Preflight Planning

(a) Weather briefing and considerations(b) Course plotting(c) Airplane Flight Manual(d) Flight plan

(3) Preflight Inspection(a) Functional test of oxygen system, including

the verification of supply and pressure, reg-ulator operation, oxygen flow, mask fit, andcockpit and air traffic control (ATC)communication using mask microphones

(4) Engine Start Procedures, Runup, Takeoff, andInitial Climb

(5) Climb to High Altitude and Normal CruiseOperations While Operating Above 25,000Feet MSL

(6) Emergencies(a) Simulated rapid decompression, including

the immediate donning of oxygen masks(b) Emergency descent

(7) Planned Descents(8) Shutdown Procedures(9) Postflight Discussion

Ch 14.qxd 5/7/04 10:09 AM Page 14-12

15-1

GENERALThis chapter contains an overview of jet poweredairplane operations. It is not meant to replace anyportion of a formal jet airplane qualification course.Rather, the information contained in this chapter ismeant to be a useful preparation for and a supplementto formal and structured jet airplane qualificationtraining. The intent of this chapter is to provideinformation on the major differences a pilot willencounter when transitioning to jet powered airplanes.In order to achieve this in a logical manner, the majordifferences between jet powered airplanes and pistonpowered airplanes have been approached byaddressing two distinct areas: differences intechnology, or how the airplane itself differs; anddifferences in pilot technique, or how the pilot dealswith the technological differences through theapplication of different techniques. If any of theinformation in this chapter conflicts with informationcontained in the FAA-approved Airplane FlightManual for a particular airplane, the Airplane FlightManual takes precedence.

JET ENGINE BASICSA jet engine is a gas turbine engine. A jet enginedevelops thrust by accelerating a relatively small massof air to very high velocity, as opposed to a propeller,which develops thrust by accelerating a much largermass of air to a much slower velocity.

As stated in Chapter 14, both piston and gas turbineengines are internal combustion engines and have asimilar basic cycle of operation; that is, induction,compression, combustion, expansion, and exhaust. Airis taken in and compressed, and fuel is injected andburned. The hot gases then expand and supply asurplus of power over that required for compression,and are finally exhausted. In both piston and jetengines, the efficiency of the cycle is improved byincreasing the volume of air taken in and thecompression ratio.

Part of the expansion of the burned gases takes place inthe turbine section of the jet engine providing thenecessary power to drive the compressor, while theremainder of the expansion takes place in the nozzle ofthe tail pipe in order to accelerate the gas to a highvelocity jet thereby producing thrust. [Figure 15-1]

In theory, the jet engine is simpler and more directlyconverts thermal energy (the burning and expansion ofgases) into mechanical energy (thrust). The piston orreciprocating engine, with all of its moving parts, mustconvert the thermal energy into mechanical energy andthen finally into thrust by rotating a propeller.

One of the advantages of the jet engine over the pistonengine is the jet engine’s capability of producing muchgreater amounts of thrust horsepower at the highaltitudes and high speeds. In fact, turbojet engineefficiency increases with altitude and speed.

Direction of Flight

AirEntersInletDuct Exhaust

Combustion

Drive Shaft

Six-Stage Compressor

TURBOJET ENGINE

Two-StageTurbine

Figure 15-1. Basic turbojet engine.

Ch 15.qxd 5/7/04 10:22 AM Page 15-1

15-2

Although the propeller driven airplane is not nearly asefficient as the jet, particularly at the higher altitudesand cruising speeds required in modern aviation, oneof the few advantages the propeller driven airplane hasover the jet is that maximum thrust is available almostat the start of the takeoff roll. Initial thrust output of thejet engine on takeoff is relatively lower and does notreach peak efficiency until the higher speeds. The fan-jet or turbofan engine was developed to help compen-sate for this problem and is, in effect, a compromisebetween the pure jet engine (turbojet) and the propellerengine.

Like other gas turbine engines, the heart of the turbo-fan engine is the gas generator—the part of the enginethat produces the hot, high-velocity gases. Similar toturboprops, turbofans have a low pressure turbine sec-tion that uses most of the energy produced by the gasgenerator. The low pressure turbine is mounted on aconcentric shaft that passes through the hollow shaft ofthe gas generator, connecting it to a ducted fan at thefront of the engine. [Figure 15-2]

Air enters the engine, passes through the fan, and splitsinto two separate paths. Some of it flows around—bypasses—the engine core, hence its name, bypassair. The air drawn into the engine for the gas generatoris the core airflow. The amount of air that bypassesthe core compared to the amount drawn into the gasgenerator determines a turbofan’s bypass ratio.Turbofans efficiently convert fuel into thrust becausethey produce low pressure energy spread over a largefan disk area. While a turbojet engine uses all of thegas generator’s output to produce thrust in the form ofa high-velocity exhaust gas jet, cool, low-velocity

bypass air produces between 30 percent and 70 per-cent of the thrust produced by a turbofan engine.

The fan-jet concept increases the total thrust of the jetengine, particularly at the lower speeds and altitudes.Although efficiency at the higher altitudes is lost (tur-bofan engines are subject to a large lapse in thrust withincreasing altitude), the turbofan engine increasesacceleration, decreases the takeoff roll, improves ini-tial climb performance, and often has the effect ofdecreasing specific fuel consumption.

OPERATING THE JET ENGINEIn a jet engine, thrust is determined by the amount offuel injected into the combustion chamber. The powercontrols on most turbojet and turbofan powered air-planes consist of just one thrust lever for each engine,because most engine control functions are automatic.The thrust lever is linked to a fuel control and/or elec-tronic engine computer that meters fuel flow basedupon r.p.m., internal temperatures, ambient conditions,and other factors. [Figure 15-3]

In a jet engine, each major rotating section usually hasa separate gauge devoted to monitoring its speed ofrotation. Depending on the make and model, a jetengine may have an N1 gauge that monitors the lowpressure compressor section and/or fan speed inturbofan engines. The gas generator section may bemonitored by an N2 gauge, while triple spool enginesmay have an N3 gauge as well. Each engine sectionrotates at many thousands of r.p.m. Their gaugestherefore are calibrated in percent of r.p.m. rather thanactual r.p.m., for ease of display and interpretation.[Figure 15-4]

Direction of Flight

InletAir

Exhaust

Combustion

Combustion

Fan Air

Fan Air

Figure 15-2.Turbofan engine.

Ch 15.qxd 5/7/04 10:22 AM Page 15-2

15-3

The temperature of turbine gases must be closelymonitored by the pilot. As in any gas turbine engine,exceeding temperature limits, even for a very fewseconds, may result in serious heat damage to turbineblades and other components. Depending on the makeand model, gas temperatures can be measured at anumber of different locations within the engine. Theassociated engine gauges therefore have differentnames according to their location. For instance:

• Exhaust Gas Temperature (EGT)—the tempera-ture of the exhaust gases as they enter the tailpipe, after passing through the turbine.

• Turbine Inlet Temperature (TIT)—the tempera-ture of the gases from the combustion section ofthe engine as they enter the first stage of the tur-bine. TIT is the highest temperature inside a gasturbine engine and is one of the limiting factorsof the amount of power the engine can produce.TIT, however, is difficult to measure. EGTtherefore, which relates to TIT, is normally theparameter measured.

• Interstage Turbine Temperature (ITT)—thetemperature of the gases between the highpressure and low pressure turbine wheels.

• Turbine Outlet Temperature (TOT)—like EGT,turbine outlet temperature is taken aft of theturbine wheel(s).

JET ENGINE IGNITIONMost jet engine ignition systems consist of two igniterplugs, which are used during the ground or air startingof the engine. Once the start is completed, this ignitioneither automatically goes off or is turned off, and fromthis point on, the combustion in the engine is acontinuous process.

CONTINUOUS IGNITIONAn engine is sensitive to the flow characteristics of theair that enters the intake of the engine nacelle. So longas the flow of air is substantially normal, the enginewill continue to run smoothly. However, particularlywith rear mounted engines that are sometimes in aposition to be affected by disturbed airflow from thewings, there are some abnormal flight situations thatcould cause a compressor stall or flameout of theengine. These abnormal flight conditions would usu-ally be associated with abrupt pitch changes such asmight be encountered in severe turbulence or a stall.

In order to avoid the possibility of engine flameoutfrom the above conditions, or from other conditionsthat might cause ingestion problems such as heavyrain, ice, or possible bird strike, most jet engines areequipped with a continuous ignition system. This sys-tem can be turned on and used continuously wheneverthe need arises. In many jets, as an added precaution,this system is normally used during takeoffs and land-ings. Many jets are also equipped with an automaticignition system that operates both igniters wheneverthe airplane stall warning or stick shaker is activated.

FUEL HEATERSBecause of the high altitudes and extremely cold out-side air temperatures in which the jet flies, it is possi-ble to supercool the jet fuel to the point that the small

Figure 15-3. Jet engine power controls.

Figure 15-4. Jet engine r.p.m. gauges.

Ch 15.qxd 5/7/04 10:22 AM Page 15-3

15-4

particles of water suspended in the fuel can turn to icecrystals and clog the fuel filters leading to the engine.For this reason, jet engines are normally equipped withfuel heaters. The fuel heater may be of the automatictype which constantly maintains the fuel temperatureabove freezing, or they may be manually controlled bythe pilot from the cockpit.

SETTING POWEROn some jet airplanes, thrust is indicated by an enginepressure ratio (EPR) gauge. Engine pressure ratio canbe thought of as being equivalent to the manifoldpressure on the piston engine. Engine pressure ratio isthe difference between turbine discharge pressure andengine inlet pressure. It is an indication of what theengine has done with the raw air scooped in. Forinstance, an EPR setting of 2.24 means that thedischarge pressure relative to the inlet pressure is2.24 : 1. On these airplanes, the EPR gauge is theprimary reference used to establish power settings.[Figure 15-5]

Fan speed (N1) is the primary indication of thrust onmost turbofan engines. Fuel flow provides a secondarythrust indication, and cross-checking for proper fuelflow can help in spotting a faulty N1 gauge. Turbofansalso have a gas generator turbine tachometer (N2).They are used mainly for engine starting and somesystem functions.

In setting power, it is usually the primary powerreference (EPR or N1) that is most critical, and will bethe gauge that will first limit the forward movement ofthe thrust levers. However, there are occasions wherethe limits of either r.p.m. or temperature can beexceeded. The rule is: movement of the thrust leversmust be stopped and power set at whichever the limitsof EPR, r.p.m., or temperature is reached first.

THRUST TO THRUST LEVERRELATIONSHIPIn a piston engine propeller driven airplane, thrust isproportional to r.p.m., manifold pressure, and propeller

blade angle, with manifold pressure being the mostdominant factor. At a constant r.p.m., thrust isproportional to throttle lever position. In a jet engine,however, thrust is quite disproportional to thrust leverposition. This is an important difference that the pilottransitioning into jet powered airplanes must becomeaccustomed to.

On a jet engine, thrust is proportional to r.p.m. (massflow) and temperature (fuel/air ratio). These arematched and a further variation of thrust results fromthe compressor efficiency at varying r.p.m. The jetengine is most efficient at high r.p.m., where theengine is designed to be operated most of the time. Asr.p.m. increases, mass flow, temperature, and effi-ciency also increase. Therefore, much more thrust isproduced per increment of throttle movement near thetop of the range than near the bottom.

One thing that will seem different to the piston pilottransitioning into jet powered airplanes is the ratherlarge amount of thrust lever movement between theflight idle position and full power as compared to thesmall amount of movement of the throttle in the pistonengine. For instance, an inch of throttle movement ona piston may be worth 400 horsepower wherever thethrottle may be. On a jet, an inch of thrust levermovement at a low r.p.m. may be worth only 200pounds of thrust, but at a high r.p.m. that same inch ofmovement might amount to closer to 2,000 pounds ofthrust. Because of this, in a situation wheresignificantly more thrust is needed and the jet engineis at low r.p.m., it will not do much good to merely“inch the thrust lever forward.” Substantial thrust levermovement is in order. This is not to say that rough orabrupt thrust lever action is standard operatingprocedure. If the power setting is already high, it maytake only a small amount of movement. However,there are two characteristics of the jet engine that workagainst the normal habits of the piston engine pilot.One is the variation of thrust with r.p.m., and the otheris the relatively slow acceleration of the jet engine.

VARIATION OF THRUST WITH RPMWhereas piston engines normally operate in the rangeof 40 percent to 70 percent of available r.p.m., jetsoperate most efficiently in the 85 percent to 100percent range, with a flight idle r.p.m. of 50 percent to60 percent. The range from 90 percent to 100 percentin jets may produce as much thrust as the totalavailable at 70 percent. [Figure 15-6]

SLOW ACCELERATION OF THE JETENGINEIn a propeller driven airplane, the constant speedpropeller keeps the engine turning at a constant r.p.m.within the governing range, and power is changed byvarying the manifold pressure. Acceleration of the

Figure 15-5. EPR gauge.

Ch 15.qxd 5/7/04 10:22 AM Page 15-4

15-5

piston from idle to full power is relatively rapid,somewhere on the order of 3 to 4 seconds. Theacceleration on the different jet engines can varyconsiderably, but it is usually much slower.

Efficiency in a jet engine is highest at high r.p.m.where the compressor is working closest to itsoptimum conditions. At low r.p.m. the operating cycleis generally inefficient. If the engine is operating atnormal approach r.p.m. and there is a suddenrequirement for increased thrust, the jet engine willrespond immediately and full thrust can be achieved inabout 2 seconds. However, at a low r.p.m., sudden fullpower application will tend to overfuel the engineresulting in possible compressor surge, excessiveturbine temperatures, compressor stall and/orflameout. To prevent this, various limiters such ascompressor bleed valves are contained in the systemand serve to restrict the engine until it is at an r.p.m. atwhich it can respond to a rapid acceleration demandwithout distress. This critical r.p.m. is most noticeablewhen the engine is at idle r.p.m. and the thrust lever israpidly advanced to a high power position. Engineacceleration is initially very slow, but changes tovery fast after about 78 percent r.p.m. is reached.[Figure 15-7]

Even though engine acceleration is nearlyinstantaneous after about 78 percent r.p.m., total timeto accelerate from idle r.p.m. to full power may take asmuch as 8 seconds. For this reason, most jets areoperated at a relatively high r.p.m. during the finalapproach to landing or at any other time thatimmediate power may be needed.

JET ENGINE EFFICIENCYMaximum operating altitudes for general aviationturbojet airplanes now reach 51,000 feet. Theefficiency of the jet engine at high altitudes is the pri-

mary reason for operating in the high altitude environ-ment. The specific fuel consumption of jet enginesdecreases as the outside air temperature decreases forconstant engine r.p.m. and true airspeed (TAS). Thus,by flying at a high altitude, the pilot is able to operateat flight levels where fuel economy is best and with themost advantageous cruise speed. For efficiency, jet air-planes are typically operated at high altitudes wherecruise is usually very close to r.p.m or exhaust gas tem-perature limits. At high altitudes, little excess thrustmay be available for maneuvering. Therefore, it isoften impossible for the jet airplane to climb and turnsimultaneously, and all maneuvering must be accom-plished within the limits of available thrust and with-out sacrificing stability and controllability.

ABSENCE OF PROPELLER EFFECTThe absence of a propeller has a significant effect onthe operation of jet powered airplanes that the transi-tioning pilot must become accustomed to. The effect isdue to the absence of lift from the propeller slipstream,and the absence of propeller drag.

ABSENCE OF PROPELLERSLIPSTREAMA propeller produces thrust by accelerating a largemass of air rearwards, and (especially with wingmounted engines) this air passes over a comparativelylarge percentage of the wing area. On a propellerdriven airplane, the lift that the wing develops is thesum of the lift generated by the wing area not in thewake of the propeller (as a result of airplane speed) andthe lift generated by the wing area influenced by thepropeller slipstream. By increasing or decreasing thespeed of the slipstream air, therefore, it is possible toincrease or decrease the total lift on the wing withoutchanging airspeed.

100

90

80

70

60

50

40

30

20

10

00 10 20 30 40 50 60 70 80 90 100

Per

cent

Max

imum

Thr

ust

Percent Maximum R.P.M.

VARIATION OF THRUST WITH R.P.M.(Constant Altitude & Velocity)

Figure 15-6. Variation of thrust with r.p.m.

8

6

4

2

60% 100%

Tim

e to

Ach

ieve

Ful

l Thr

ust (

sec.

)

R.P.M.

78%

Figure 15-7.Typical Jet engine acceleration times.

Ch 15.qxd 5/7/04 10:22 AM Page 15-5

15-6

For example, a propeller driven airplane that is allowedto become too low and too slow on an approach is veryresponsive to a quick blast of power to salvage thesituation. In addition to increasing lift at a constantairspeed, stalling speed is reduced with power on. A jetengine, on the other hand, also produces thrust byaccelerating a mass of air rearward, but this air doesnot pass over the wings. There is therefore no lift bonusat increased power at constant airspeed, and nosignificant lowering of power-on stall speed.

In not having propellers, the jet powered airplane isminus two assets.

• It is not possible to produce increased liftinstantly by simply increasing power.

• It is not possible to lower stall speed by simplyincreasing power. The 10-knot margin (roughlythe difference between power-off and power-onstall speed on a propeller driven airplane for agiven configuration) is lost.

Add the poor acceleration response of the jet engineand it becomes apparent that there are three ways inwhich the jet pilot is worse off than the propeller pilot.For these reasons, there is a marked difference betweenthe approach qualities of a piston engine airplane and ajet. In a piston engine airplane, there is some room forerror. Speed is not too critical and a burst of power willsalvage an increasing sink rate. In a jet, however, thereis little room for error.

If an increasing sink rate develops in a jet, the pilotmust remember two points in the proper sequence.

1. Increased lift can be gained only by acceleratingairflow over the wings, and this can beaccomplished only by accelerating the entireairplane.

2. The airplane can be accelerated, assumingaltitude loss cannot be afforded, only by a rapidincrease in thrust, and here, the slow accelerationof the jet engine (possibly up to 8 seconds)becomes a factor.

Salvaging an increasing sink rate on an approach in ajet can be a very difficult maneuver. The lack of abilityto produce instant lift in the jet, along with the slowacceleration of the engine, necessitates a “stabilizedapproach” to a landing where full landingconfiguration, constant airspeed, controlled rate ofdescent, and relatively high power settings aremaintained until over the threshold of the runway. Thisallows for almost immediate response from the enginein making minor changes in the approach speed or rateof descent and makes it possible to initiate animmediate go-around or missed approach if necessary.

ABSENCE OF PROPELLER DRAGWhen the throttles are closed on a piston poweredairplane, the propellers create a vast amount of drag,and airspeed is immediately decreased or altitude lost.The effect of reducing power to idle on the jet engine,however, produces no such drag effect. In fact, at anidle power setting, the jet engine still producesforward thrust. The main advantage is that the jet pilotis no longer faced with a potential drag penalty of arunaway propeller, or a reversed propeller. Adisadvantage, however, is the “free wheeling” effectforward thrust at idle has on the jet. While thisoccasionally can be used to advantage (such as in along descent), it is a handicap when it is necessary tolose speed quickly, such as when entering a terminalarea or when in a landing flare. The lack of propellerdrag, along with the aerodynamically clean airframeof the jet, are new to most pilots, and slowing theairplane down is one of the initial problemsencountered by pilots transitioning into jets.

SPEED MARGINSThe typical piston powered airplane had to deal withtwo maximum operating speeds.

• VNO—Maximum structural cruising speed,represented on the airspeed indicator by theupper limit of the green arc. It is, however,permissible to exceed VNO and operate in thecaution range (yellow arc) in certain flightconditions.

• VNE—Never-exceed speed, represented by a redline on the airspeed indicator.

These speed margins in the piston airplanes werenever of much concern during normal operationsbecause the high drag factors and relatively low cruisepower settings kept speeds well below these maximumlimits.

Maximum speeds in jet airplanes are expresseddifferently, and always define the maximum operatingspeed of the airplane which is comparable to the VNEof the piston airplane. These maximum speeds in a jetairplane are referred to as:

• VMO—Maximum operating speed expressed interms of knots.

• MMO—Maximum operating speed expressed interms of a decimal of Mach speed (speed ofsound).

To observe both limits VMO and MMO, the pilot of a jetairplane needs both an airspeed indicator and aMachmeter, each with appropriate red lines. In somegeneral aviation jet airplanes, these are combined into

Ch 15.qxd 5/7/04 10:22 AM Page 15-6

15-7

a single instrument that contains a pair of concentricindicators, one for the indicated airspeed and the otherfor indicated Mach number. Each is provided with anappropriate red line. [Figure 15-8]

A more sophisticated indicator is used on mostjetliners. It looks much like a conventional airspeedindicator but has a “barber pole” that automaticallymoves so as to display the applicable speed limit at alltimes.

Because of the higher available thrust and very lowdrag design, the jet airplane can very easily exceed itsspeed margin even in cruising flight, and in fact insome airplanes in a shallow climb. The handlingqualities in a jet can change drastically when themaximum operating speeds are exceeded.

High speed airplanes designed for subsonic flight arelimited to some Mach number below the speed ofsound to avoid the formation of shock waves that beginto develop as the airplane nears Mach 1.0. These shockwaves (and the adverse effects associated with them)can occur when the airplane speed is substantiallybelow Mach 1.0. The Mach speed at which someportion of the airflow over the wing first equals Mach1.0 is termed the critical Mach number (MACHCRIT).This is also the speed at which a shock wave firstappears on the airplane.

There is no particular problem associated with theacceleration of the airflow up to the point where Mach1.0 is encountered; however, a shock wave is formed atthe point where the airflow suddenly returns tosubsonic flow. This shock wave becomes more severeand moves aft on the wing as speed of the wing isincreased, and eventually flow separation occursbehind the well-developed shock wave. [Figure 15-9]

If allowed to progress well beyond the MMO for theairplane, this separation of air behind the shock wavecan result in severe buffeting and possible loss ofcontrol or “upset.”

Because of the changing center of lift of the wingresulting from the movement of the shock wave, thepilot will experience pitch change tendencies as theairplane moves through the transonic speeds up to andexceeding MMO. [Figure 15-10]

For example, as the graph in figure 15-10 illustrates,initially as speed is increased up to Mach .72 the wingdevelops an increasing amount of lift requiring a nose-down force or trim to maintain level flight. Withincreased speed and the aft movement of the shockwave, the wing’s center of pressure also moves aftcausing the start of a nosedown tendency or “tuck.” ByMach .83 the nosedown forces are well developed to apoint where a total of 70 pounds of back pressure arerequired to hold the nose up. If allowed to progressunchecked, Mach tuck may eventually occur.Although Mach tuck develops gradually, if it is

Figure 15-8. Jet airspeed indicator.

M=.72 (Critical Mach Number)

M=.77

SupersonicFlow

M=.82

Normal Shock Wave

SubsonicPossible

Separation

SupersonicFlow

Normal Shock

Normal Shock

Separation

Maximum Local VelocityIs Less Than Sonic

Figure 15-9.Transonic flow patterns.

70

60

50

40

30

20

10

0

10

20

00.3 0.4 0.5 0.6 0.7 0.8 0.9

Stic

k F

orce

in P

ound

s

Mach Number

Pull

Push

Figure 15-10. Example of Stick Forces vs. Mach Number in atypical jet airplane.

Ch 15.qxd 5/7/04 10:22 AM Page 15-7

15-8

allowed to progress significantly, the center ofpressure can move so far rearward that there is nolonger enough elevator authority available tocounteract it, and the airplane could enter a steep,sometimes unrecoverable dive.

An alert pilot would have observed the high airspeedindications, experienced the onset of buffeting, andresponded to aural warning devices long beforeencountering the extreme stick forces shown.However, in the event that corrective action is nottaken and the nose allowed to drop, increasing airspeedeven further, the situation could rapidly becomedangerous. As the Mach speed increases beyond theairplane’s MMO, the effects of flow separation andturbulence behind the shock wave become moresevere. Eventually, the most powerful forces causingMach tuck are a result of the buffeting and lack ofeffective downwash on the horizontal stabilizerbecause of the disturbed airflow over the wing. This isthe primary reason for the development of the T-tailconfiguration on some jet airplanes, which places thehorizontal stabilizer as far as practical from theturbulence of the wings. Also, because of the criticalaspects of high-altitude/high-Mach flight, most jetairplanes capable of operating in the Mach speedranges are designed with some form of trim andautopilot Mach compensating device (stick puller) toalert the pilot to inadvertent excursions beyond itscertificated MMO.

RECOVERY FROM OVERSPEEDCONDITIONSThe simplest remedy for an overspeed condition is toensure that the situation never occurs in the first place.For this reason, the pilot must be aware of all theconditions that could lead to exceeding the airplane’smaximum operating speeds. Good attitude instrumentflying skills and good power control are essential.

The pilot should be aware of the symptoms that will beexperienced in the particular airplane as the VMO orMMO is being approached. These may include:

• Nosedown tendency and need for back pressureor trim.

• Mild buffeting as airflow separation begins tooccur after critical Mach speed.

• Actuation of an aural warning device/stick pullerat or just slightly beyond VMO or MMO.

The pilot’s response to an overspeed condition shouldbe to immediately slow the airplane by reducing thepower to flight idle. It will also help to smoothly andeasily raise the pitch attitude to help dissipate speed (infact this is done automatically through the stick pullerdevice when the high speed warning system is

activated). The use of speed brakes can also aid inslowing the airplane. If, however, the nosedown stickforces have progressed to the extent that they areexcessive, some speed brakes will tend to furtheraggravate the nosedown tendency. Under mostconditions, this additional pitch down force is easilycontrollable, and since speed brakes can normally beused at any speed, they are a very real asset. A finaloption would be to extend the landing gear. This willcreate enormous drag and possibly some noseup pitch,but there is usually little risk of damage to the gearitself. The pilot transitioning into jet airplanes must befamiliar with the manufacturers’ recommended proce-dures for dealing with overspeed conditions containedin the FAA-approved Airplane Flight Manual for theparticular make and model airplane.

MACH BUFFET BOUNDARIESThus far, only the Mach buffet that results fromexcessive speed has been addressed. The transitioningpilot, however, should be aware that Mach buffet is afunction of the speed of the airflow over the wing—not necessarily the airspeed of the airplane. Anytimethat too great a lift demand is made on the wing,whether from too fast an airspeed or from too high anangle of attack near the MMO, the “high speed buffet”will occur. However, there are also occasions when thebuffet can be experienced at much slower speedsknown as “low speed Mach buffet.”

The most likely situations that could cause the lowspeed buffet would be when an airplane is flown at tooslow a speed for its weight and altitude causing a highangle of attack. This very high angle of attack wouldhave the same effect of increasing airflow over theupper surface of the wing to the point that all of thesame effects of the shock waves and buffet wouldoccur as in the high speed buffet situation.

The angle of attack of the wing has the greatest effecton inducing the Mach buffet at either the high or lowspeed boundaries for the airplane. The conditions thatincrease the angle of attack, hence the speed of theairflow over the wing and chances of Mach buffet are:

• High altitudes—The higher the airplane flies,the thinner the air and the greater the angle ofattack required to produce the lift needed tomaintain level flight.

• Heavy weights—The heavier the airplane, thegreater the lift required of the wing, and all otherthings being equal, the greater the angle ofattack.

• “G” loading—An increase in the “G” loading ofthe wing results in the same situation asincreasing the weight of the airplane. It makes

Ch 15.qxd 5/7/04 10:22 AM Page 15-8

15-9

no difference whether the increase in “G” forcesis caused by a turn, rough control usage, or tur-bulence. The effect of increasing the wing’sangle of attack is the same.

An airplane’s indicated airspeed decreases in relationto true airspeed as altitude increases. As the indicatedairspeed decreases with altitude, it progressivelymerges with the low speed buffet boundary where pre-stall buffet occurs for the airplane at a load factor of1.0 G. The point where the high speed Mach indicatedairspeed and low speed buffet boundary indicated air-speed merge is the airplane’s absolute or aerodynamicceiling. Once an airplane has reached its aerodynamicceiling, which is higher than the altitude stipulated inthe FAA-approved Airplane Flight Manual, the air-plane can neither be made to go faster without activat-ing the design stick puller at Mach limit nor can it bemade to go slower without activating the stick shakeror stick pusher. This critical area of the airplane’sflight envelope is known as “coffin corner.”

Mach buffet occurs as a result of supersonic airflow onthe wing. Stall buffet occurs at angles of attack thatproduce airflow disturbances (burbling) over the uppersurface of the wing which decreases lift. As densityaltitude increases, the angle of attack that is required toproduce an airflow disturbance over the top of the wingis reduced until the density altitude is reached whereMach buffet and stall buffet converge (coffin corner).

When this phenomenon is encountered, serious conse-quences may result causing loss of airplane control.

Increasing either gross weight or load factor (G factor)will increase the low speed buffet and decrease Machbuffet speeds. A typical jet airplane flying at 51,000feet altitude at 1.0 G may encounter Mach buffetslightly above the airplane’s MMO (.82 Mach) and lowspeed buffet at .60 Mach. However, only 1.4 G (anincrease of only 0.4 G) may bring on buffet at the opti-mum speed of .73 Mach and any change in airspeed,bank angle, or gust loading may reduce this straight-and-level flight 1.4 G protection to no protection at all.Consequently, a maximum cruising flight altitude mustbe selected which will allow sufficient buffet marginfor necessary maneuvering and for gust conditionslikely to be encountered. Therefore, it is important forpilots to be familiar with the use of charts showingcruise maneuver and buffet limits. [Figure 15-11]

The transitioning pilot must bear in mind that themaneuverability of the jet airplane is particularly criti-cal, especially at the high altitudes. Some jet airplaneshave a very narrow span between the high and lowspeed buffets. One airspeed that the pilot should havefirmly fixed in memory is the manufacturer’s recom-mended gust penetration speed for the particular makeand model airplane. This speed is normally the speedthat would give the greatest margin between the highand low speed buffets, and may be considerably higher

1 2 3 .1 .2 .3 .4 .5 .6 .7 .8

Load Factor – G Indicated Mach Number

Sea

Lev

el

5,00

0

10,0

00

15,0

00

20,0

00

Press

ure

Altitud

e – 25,000 Ft.

30,000

35,000

40,00040,000

45,00045,000

MMO

19,000 Lbs.

11,000

18,000

17,000

16,000

15,000

14,000

13,000

12,000

A

BC

D

Figure 15-11. Mach buffet boundary chart.

Ch 15.qxd 5/7/04 10:22 AM Page 15-9

15-10

than design maneuvering speed (VA). This means that,unlike piston airplanes, there are times when a jetairplane should be flown in excess of VA duringencounters with turbulence. Pilots operating airplanesat high speeds must be adequately trained to operatethem safely. This training cannot be complete untilpilots are thoroughly educated in the critical aspects ofthe aerodynamic factors pertinent to Mach flight athigh altitudes.

LOW SPEED FLIGHTThe jet airplane wing, designed primarily for highspeed flight, has relatively poor low speedcharacteristics. As opposed to the normal pistonpowered airplane, the jet wing has less area, a loweraspect ratio (long chord/short span), and thin airfoilshape—all of which amount to less lift. The sweptwingis additionally penalized at low speeds because theeffective lift, which is perpendicular to the leadingedge, is always less than the airspeed of the airplaneitself. In other words, the airflow on the sweptwing hasthe effect of persuading the wing into believing that itis flying slower than it actually is, but the wing conse-quently suffers a loss of lift for a given airspeed at agiven angle of attack.

The first real consequence of poor lift at low speeds isa high stall speed. The second consequence of poor liftat low speeds is the manner in which lift and drag varywith speed in the lower ranges. As a jet airplane isslowed toward its minimum drag speed (VMD orL/DMAX), total drag increases at a much greater ratethan lift, resulting in a sinking flightpath. If the pilotattempts to increase lift by increasing pitch attitude,airspeed will be further reduced resulting in a furtherincrease in drag and sink rate as the airplane slides upthe back side of the power curve. The sink rate can bearrested in one of two ways:

• Pitch attitude can be substantially reduced toreduce the angle of attack and allow the airplaneto accelerate to a speed above VMD, where steadyflight conditions can be reestablished. Thisprocedure, however, will invariably result in asubstantial loss of altitude.

• Thrust can be increased to accelerate the airplaneto a speed above VMD to reestablish steady flightconditions. It should be remembered that theamount of thrust required will be quite large. Theamount of thrust must be sufficient to acceleratethe airplane and regain altitude lost. Also, if theairplane has slid a long way up the back side ofthe power required (drag) curve, drag will bevery high and a very large amount of thrust willbe required.

In a typical piston engine airplane, VMD in the cleanconfiguration is normally at a speed of about 1.3 VS.[Figure 15-12] Flight below VMD on a piston engineairplane is well identified and predictable. In contrast,in a jet airplane flight in the area of VMD (typically 1.5– 1.6 VS) does not normally produce any noticeablechanges in flying qualities other than a lack of speedstability—a condition where a decrease in speed leadsto an increase in drag which leads to a further decreasein speed and hence a speed divergence. A pilot who isnot cognizant of a developing speed divergence mayfind a serious sink rate developing at a constant powersetting, and a pitch attitude that appears to be normal.The fact that drag increases more rapidly than lift,causing a sinking flightpath, is one of the mostimportant aspects of jet airplane flying qualities.

STALLSThe stalling characteristics of the sweptwing jetairplane can vary considerably from those of the

MinimumPowerRequired

L/DMAX

Figure 15-12.Thrust and power required curves.

Ch 15.qxd 5/7/04 10:22 AM Page 15-10

15-11

normal straight wing airplane. The greatest differencethat will be noticeable to the pilot is the lift developedvs. angle of attack. An increase in angle of attack of thestraight wing produces a substantial and constantlyincreasing lift vector up to its maximum coefficient oflift, and soon thereafter flow separation (stall) occurswith a rapid deterioration of lift.

By contrast, the sweptwing produces a much moregradual buildup of lift with no well defined maximumcoefficient and has the ability to fly well beyond thismaximum buildup even though lift is lost. The dragcurves (which are not depicted in figure 15-13) areapproximately the reverse of the lift curves shown, inthat a rapid increase in drag component may beexpected with an increase in the angle of attack of asweptwing airplane.

The differences in the stall characteristics between aconventional straight wing/low tailplane (non T-tail)airplane and a sweptwing T-tail airplane center aroundtwo main areas.

• The basic pitching tendency of the airplane atthe stall.

• Tail effectiveness in stall recovery.

On a conventional straight wing/low tailplane airplane,the weight of the airplane acts downwards forward ofthe lift acting upwards, producing a need for abalancing force acting downwards from the tailplane.As speed is reduced by gentle up elevator deflection,the static stability of the airplane causes a nosedowntendency. This is countered by further up elevator tokeep the nose coming up and the speed decreasing. Asthe pitch attitude increases, the low set tail is immersedin the wing wake, which is slightly turbulent, lowenergy air. The accompanying aerodynamic buffetingserves as a warning of impending stall. The reducedeffectiveness of the tail prevents the pilot from forcing

the airplane into a deeper stall. [Figure 15-14] Theconventional straight wing airplane conforms to thefamiliar nosedown pitching tendency at the stall andgives the entire airplane a fairly pronounced nosedownpitch. At the moment of stall, the wing wake passesmore or less straight rearward and passes above thetail. The tail is now immersed in high energy air whereit experiences a sharp increase in positive angle ofattack causing upward lift. This lift then assists thenosedown pitch and decrease in wing angle of attackessential to stall recovery.

In a sweptwing jet with a T-tail and rear fuselagemounted engines, the two qualities that are differentfrom its straight wing low tailplane counterpart are thepitching tendency of the airplane as the stall developsand the loss of tail effectiveness at the stall. Thehandling qualities down to the stall are much the sameas the straight wing airplane except that the high, T-tailremains clear of the wing wake and provides little orno warning in the form of a pre-stall buffet. Also, thetail is fully effective during the speed reductiontowards the stall, and remains effective even after thewing has begun to stall. This enables the pilot to drivethe wing into a deeper stall at a much greater angleof attack.

At the stall, two distinct things happen. After the stall,the sweptwing T-tail airplane tends to pitch up ratherthan down, and the T-tail is immersed in the wingwake, which is low energy turbulent air. This greatlyreduces tail effectiveness and the airplane’s ability tocounter the noseup pitch. Also, the disturbed,relatively slow air behind the wing may sweep acrossthe tail at such a large angle that the tail itself stalls. Ifthis occurs, the pilot loses all pitch control and will beunable to lower the nose. The pitch up just after thestall is worsened by large reduction in lift and a largeincrease in drag, which causes a rapidly increasing

Lift

Coe

ffici

ent

Angle of Attack

StraightWing

Sweptwing

Figure 15-13. Stall vs. angle of attack—sweptwing vs. straightwing.

Figure 15-14. Stall progression—typical straight wingairplane.

Ch 15.qxd 5/7/04 10:22 AM Page 15-11

15-12

descent path, thus compounding the rate of increase ofthe wing’s angle of attack. [Figure 15-15]

The pitch up tendency after the stall is a characteristicof a swept and/or tapered wings. With these types ofwings, there is a tendency for the wing to develop astrong spanwise airflow towards the wingtip when thewing is at high angles of attack. This leads to a

tendency for separation of airflow, and the subsequentstall, to occur at the wingtips first. [Figure 15-16] Thetip first stall, results in a shift of the center of lift of thewing in a forward direction relative to the center ofgravity of the airplane, causing the nose to pitch up.Another disadvantage of a tip first stall is that it caninvolve the ailerons and erode roll control.

As previously stated, when flying at a speed in the areaof VMD, an increase in angle of attack causes drag toincrease faster than lift and the airplane begins to sink.It is essential to understand that this increasing sinkingtendency, at a constant pitch attitude, results in a rapidincrease in angle of attack as the flightpath becomesdeflected downwards. [Figure 15-17] Furthermore,once the stall has developed and a large amount of lifthas been lost, the airplane will begin to sink rapidlyand this will be accompanied by a corresponding rapidincrease in angle of attack. This is the beginning ofwhat is termed a deep stall.

As an airplane enters a deep stall, increasing dragreduces forward speed to well below normal stallspeed. The sink rate may increase to many thousandsof feet per minute. The airplane eventually stabilizesin a vertical descent. The angle of attack may approach

Pre-Stall

Stall

Figure 15-15. Stall progression sweptwing airplane.

Spanwise Flow of BoundaryLayer Develops at High CL

Initial Flow Separationat or Near Tip

Area of TipStall Enlarges

Stall Area ProgressesInboard

Figure 15-16. Sweptwing stall characteristics.

Ch 15.qxd 5/7/04 10:22 AM Page 15-12

15-13

90° and the indicated airspeed may be reduced to zero.At a 90° angle of attack, none of the airplane’s controlsurfaces are effective. It must be emphasized that thissituation can occur without an excessively nose-highpitch attitude. On some airplanes, it can occur at anapparently normal pitch attitude, and it is this qualitythat can mislead the pilot because it appears similar tothe beginning of a normal stall recovery.

Deep stalls are virtually unrecoverable. Fortunately,they are easily avoided as long as published limitationsare observed. On those airplanes susceptible to deepstalls (not all swept and/or tapered wing airplanes are),sophisticated stall warning systems such as stickshakers and stick pushers are standard equipment. Astick pusher, as its name implies, acts to automaticallyreduce the airplane’s angle of attack before the airplanereaches a fully stalled condition.

Unless the Airplane Flight Manual proceduresstipulate otherwise, a fully stalled condition in a jetairplane is to be avoided. Pilots undergoing training injet airplanes are taught to recover at the first sign of animpending stall. Normally, this is indicated by auralstall warning devices and/or activation of the airplane’sstick shaker. Stick shakers normally activate around107 percent of the actual stall speed. At such slowspeeds, very high sink rates can develop if theairplane’s pitch attitude is decreased below thehorizon, as is normal recovery procedure in mostpiston powered straight wing, light airplanes.Therefore, at the lower altitudes where plenty ofengine thrust is available, the recovery technique inmany sweptwing jets involves applying full availablepower, rolling the wings level, and holding a slightlypositive pitch attitude. The amount of pitch attitude

should be sufficient enough to maintain altitude orbegin a slight climb.

At high altitudes, where there may be little excessthrust available to effect a recovery using power alone,it may be necessary to lower the nose below thehorizon in order to accelerate away from an impendingstall. This procedure may require several thousand feetor more of altitude loss to effect a recovery. Stallrecovery techniques may vary considerably fromairplane to airplane. The stall recovery procedures fora particular make and model airplane, asrecommended by the manufacturer, are contained inthe FAA-approved Airplane Flight Manual forthat airplane.

DRAG DEVICESTo the pilot transitioning into jet airplanes, going fasteris seldom a problem. It is getting the airplane to slowdown that seems to cause the most difficulty. This isbecause of the extremely clean aerodynamic designand fast momentum of the jet airplane, and alsobecause the jet lacks the propeller drag effects that thepilot has been accustomed to. Additionally, even withthe power reduced to flight idle, the jet engine stillproduces thrust, and deceleration of the jet airplane is aslow process. Jet airplanes have a glide performancethat is double that of piston powered airplanes, and jetpilots often cannot comply with an air traffic controlrequest to go down and slow down at the same time.Therefore, jet airplanes are equipped with drag devicessuch as spoilers and speed brakes.

The primary purpose of spoilers is to spoil lift. Themost common type of spoiler consists of one or morerectangular plates that lie flush with the upper surfaceof each wing. They are installed approximatelyparallel to the lateral axis of the airplane and are hingedalong the leading edges. When deployed, spoilersdeflect up against the relative wind, which interfereswith the flow of air about the wing. [Figure 15-18] Thisboth spoils lift and increases drag. Spoilers are usuallyinstalled forward of the flaps but not in front of theailerons so as not to interfere with roll control.

Initial Stall

Deep Stall

Pre-Stall

Relative Wind

Relative Wind

Relative W

ind

Pitch Attitude

Flightpath Angle to the Horizontal

Angle of Attack

Figure 15-17. Deep stall progression.

Figure 15-18. Spoilers.

Ch 15.qxd 5/7/04 10:22 AM Page 15-13

15-14

Deploying spoilers results in a substantial sink ratewith little decay in airspeed. Some airplanes willexhibit a noseup pitch tendency when the spoilers aredeployed, which the pilot must anticipate.

When spoilers are deployed on landing, most of thewing’s lift is destroyed. This action transfers theairplane’s weight to the landing gear so that the wheelbrakes are more effective. Another beneficial effect ofdeploying spoilers on landing is that they createconsiderable drag, adding to the overall aerodynamicbraking. The real value of spoilers on landing, how-ever, is creating the best circumstances for usingwheel brakes.

The primary purpose of speed brakes is to producedrag. Speed brakes are found in many sizes, shapes,and locations on different airplanes, but they all havethe same purpose—to assist in rapid deceleration. Thespeed brake consists of a hydraulically operated boardthat when deployed extends into the airstream.Deploying speed brakes results in a rapid decrease inairspeed. Typically, speed brakes can be deployed atany time during flight in order to help control airspeed,but they are most often used only when a rapid decel-eration must be accomplished to slow down to landinggear and flap speeds. There is usually a certain amountof noise and buffeting associated with the use of speedbrakes, along with an obvious penalty in fuel con-sumption. Procedures for the use of spoilers and/orspeed brakes in various situations are contained in theFAA-approved Airplane Flight Manual for the particu-lar airplane.

THRUST REVERSERSJet airplanes have high kinetic energy during thelanding roll because of weight and speed. This energyis difficult to dissipate because a jet airplane has lowdrag with the nosewheel on the ground and the enginescontinue to produce forward thrust with the powerlevers at idle. While wheel brakes normally can cope,there is an obvious need for another speed retardingmethod. This need is satisfied by the drag provided byreverse thrust.

A thrust reverser is a device fitted in the engineexhaust system which effectively reverses the flow ofthe exhaust gases. The flow does not reverse through180°; however, the final path of the exhaust gases isabout 45° from straight ahead. This, together with thelosses in the reverse flow paths, results in a net effi-ciency of about 50 percent. It will produce even less ifthe engine r.p.m. is less than maximum in reverse.

Normally, a jet engine will have one of two types ofthrust reversers, either a target reverser or a cascadereverser. [Figure 15-19] Target reversers are simpleclamshell doors that swivel from the stowed position at

the engine tailpipe to block all of the outflow andredirect some component of the thrust forward.

Cascade reversers are more complex. They arenormally found on turbofan engines and are oftendesigned to reverse only the fan air portion. Blockingdoors in the shroud obstructs forward fan thrust andredirects it through cascade vanes for some reversecomponent. Cascades are generally less effective thantarget reversers, particularly those that reverse onlyfan air, because they do not affect the engine core,which will continue to produce forward thrust.

On most installations, reverse thrust is obtained withthe thrust lever at idle, by pulling up the reverse leverto a detent. Doing so positions the reversingmechanisms for operation but leaves the engine at idler.p.m. Further upward and backward movement of thereverse lever increases engine power. Reverse iscancelled by closing the reverse lever to the idlereverse position, then dropping it fully back to theforward idle position. This last movement operates thereverser back to the forward thrust position.

Reverse thrust is much more effective at high airplanespeed than at low airplane speeds, for two reasons:first, the net amount of reverse thrust increases withspeed; second, the power produced is higher at higherspeeds because of the increased rate of doing work. Inother words, the kinetic energy of the airplane is beingdestroyed at a higher rate at the higher speeds. To getmaximum efficiency from reverse thrust, therefore, itshould be used as soon as is prudent after touchdown.

When considering the proper time to apply reversethrust after touchdown, the pilot should remember that

TARGET OR CLAMSHELL REVERSER

CASCADE REVERSER

Figure 15-19.Thrust reversers.

Ch 15.qxd 5/7/04 10:22 AM Page 15-14

15-15

some airplanes tend to pitch noseup when reverse isselected on landing and this effect, particularly whencombined with the noseup pitch effect from thespoilers, can cause the airplane to leave the groundagain momentarily. On these types, the airplane mustbe firmly on the ground with the nosewheel down,before reverse is selected. Other types of airplaneshave no change in pitch, and reverse idle may beselected after the main gear is down and before thenosewheel is down. Specific procedures for reversethrust operation for a particular airplane/enginecombination are contained in the FAA-approvedAirplane Flight Manual for that airplane.

There is a significant difference between reverse pitchon a propeller and reverse thrust on a jet. Idle reverseon a propeller produces about 60 percent of the reversethrust available at full power reverse and is thereforevery effective at this setting when full reverse is notneeded. On a jet engine, however, selecting idlereverse produces very little actual reverse thrust. In ajet airplane, the pilot must not only select reverse assoon as reasonable, but then must open up to full powerreverse as soon as possible. Within Airplane FlightManual limitations, full power reverse should be helduntil the pilot is certain the landing roll will becontained within the distance available.

Inadvertent deployment of thrust reversers is a veryserious emergency situation. Therefore, thrust reversersystems are designed with this prospect in mind. Thesystems normally contain several lock systems: one tokeep reversers from operating in the air, another toprevent operation with the thrust levers out of the idledetent, and/or an “auto-stow” circuit to commandreverser stowage any time unwanted motion isdetected. It is essential that pilots understand not onlythe normal procedures and limitations of thrustreverser use, but also the procedures for coping withuncommanded reverse. Those emergencies demandimmediate and accurate response.

PILOT SENSATIONS IN JET FLYINGThere are usually three general sensations that the pilottransitioning into jets will immediately become awareof. These are: inertial response differences, increasedcontrol sensitivity, and a much increased tempoof flight.

The varying of power settings from flight idle to fulltakeoff power has a much slower effect on the changeof airspeed in the jet airplane. This is commonly calledlead and lag, and is as much a result of the extremelyclean aerodynamic design of the airplane as it is theslower response of the engine.

The lack of propeller effect is also responsible for thelower drag increment at the reduced power settings and

results in other changes that the pilot will have tobecome accustomed to. These include the lack ofeffective slipstream over the lifting surfaces andcontrol surfaces, and lack of propeller torque effect.

The aft mounted engines will cause a different reactionto power application and may result in a slightly nose-down pitching tendency with the application of power.On the other hand, power reduction will not cause thenose of the airplane to drop to the same extent the pilotis used to in a propeller airplane. Although neither ofthese characteristics are radical enough to causetransitioning pilots much of a problem, they must becompensated for.

Power settings required to attain a given performanceare almost impossible to memorize in the jets, and thepilot who feels the necessity for having an array ofpower settings for all occasions will initially feel at aloss. The only way to answer the question of “howmuch power is needed?” is by saying, “whatever isrequired to get the job done.” The primary reason thatpower settings vary so much is because of the greatchanges in weight as fuel is consumed during theflight. Therefore, the pilot will have to learn to usepower as needed to achieve the desired performance.In time the pilot will find that the only reference topower instruments will be that required to keep fromexceeding limits of maximum power settings or tosynchronize r.p.m.

Proper power management is one of the initial problemareas encountered by the pilot transitioning into jetairplanes. Although smooth power applications are stillthe rule, the pilot will be aware that a greater physicalmovement of the power levers is required as comparedto throttle movement in the piston engines. The pilotwill also have to learn to anticipate and lead the powerchanges more than in the past and must keep in mindthat the last 30 percent of engine r.p.m. represents themajority of the engine thrust, and below that theapplication of power has very little effect. In slowingthe airplane, power reduction must be made soonerbecause there is no longer any propeller drag and thepilot should anticipate the need for drag devices.

Control sensitivity will differ between variousairplanes, but in all cases, the pilot will find that theyare more sensitive to any change in controldisplacement, particularly pitch control, than are theconventional propeller airplanes. Because of the higherspeeds flown, the control surfaces are more effectiveand a variation of just a few degrees in pitch attitude ina jet can result in over twice the rate of altitude changethat would be experienced in a slower airplane. Thesensitive pitch control in jet airplanes is one of the firstflight differences that the pilot will notice. Invariablythe pilot will have a tendency to over-control pitch

Ch 15.qxd 5/7/04 10:22 AM Page 15-15

15-16

during initial training flights. The importance ofaccurate and smooth control cannot be overempha-sized, however, and it is one of the first techniques thetransitioning pilot must master.

The pilot of a sweptwing jet airplane will soon becomeadjusted to the fact that it is necessary and normal tofly at higher angles of attack. It is not unusual to haveabout 5° of noseup pitch on an approach to a landing.During an approach to a stall at constant altitude, thenoseup angle may be as high as 15° to 20°. The higherdeck angles (pitch angle relative to the ground) ontakeoff, which may be as high as 15°, will also takesome getting used to, although this is not the actualangle of attack relative to the airflow over the wing.

The greater variation of pitch attitudes flown in a jetairplane are a result of the greater thrust available andthe flight characteristics of the low aspect ratio andsweptwing. Flight at the higher pitch attitudes requiresa greater reliance on the flight instruments for airplanecontrol since there is not much in the way of a usefulhorizon or other outside reference to be seen. Becauseof the high rates of climb and descent, high airspeeds,high altitudes and variety of attitudes flown, the jetairplane can only be precisely flown by applyingproficient instrument flight techniques. Proficiency inattitude instrument flying, therefore, is essential tosuccessful transition to jet airplane flying.

Most jet airplanes are equipped with a thumb operatedpitch trim button on the control wheel which the pilotmust become familiar with as soon as possible. The jetairplane will differ regarding pitch tendencies with thelowering of flaps, landing gear, and drag devices. Withexperience, the jet airplane pilot will learn to anticipatethe amount of pitch change required for a particularoperation. The usual method of operating the trimbutton is to apply several small, intermittentapplications of trim in the direction desired rather thanholding the trim button for longer periods of timewhich can lead to over-controlling.

JET AIRPLANE TAKEOFF AND CLIMBAll FAA certificated jet airplanes are certificated underTitle 14 of the Code of Federal Regulations (14 CFR)part 25, which contains the airworthiness standards fortransport category airplanes. The FAA certificated jetairplane is a highly sophisticated machine with provenlevels of performance and guaranteed safety margins.The jet airplane’s performance and safety margins canonly be realized, however, if the airplane is operated instrict compliance with the procedures and limitationscontained in the FAA-approved Airplane FlightManual for the particular airplane.

The following information is generic in nature and,since most civilian jet airplanes require a minimum

flight crew of two pilots, assumes a two pilot crew. Ifany of the following information conflicts with FAA-approved Airplane Flight Manual procedures for aparticular airplane, the Airplane Flight Manualprocedures take precedence. Also, if any of thefollowing procedures differ from the FAA-approvedprocedures developed for use by a specific air operatorand/or for use in an FAA-approved training center orpilot school curriculum, the FAA-approvedprocedures for that operator and/or trainingcenter/pilot school take precedence.

V-SPEEDSThe following are speeds that will affect the jetairplane’s takeoff performance. The jet airplane pilotmust be thoroughly familiar with each of these speedsand how they are used in the planning of the takeoff.

• VS—Stall speed.

• V1—Critical engine failure speed or decisionspeed. Engine failure below this speed shouldresult in an aborted takeoff; above this speed thetakeoff run should be continued.

• VR—Speed at which the rotation of the airplaneis initiated to takeoff attitude. This speed cannotbe less than V1 or less than 1.05 x VMCA(minimum control speed in the air). On asingle-engine takeoff, it must also allow for theacceleration to V2 at the 35-foot height at the endof the runway.

• VLO—The speed at which the airplane firstbecomes airborne. This is an engineering termused when the airplane is certificated and mustmeet certain requirements. If it is not listed in theAirplane Flight Manual, it is withinrequirements and does not have to be taken intoconsideration by the pilot.

• V2—The takeoff safety speed which must beattained at the 35-foot height at the end of therequired runway distance. This is essentially thebest single-engine angle of climb speed for theairplane and should be held until clearingobstacles after takeoff, or at least 400 feet abovethe ground.

PRE-TAKEOFF PROCEDURESTakeoff data, including V1/VR and V2 speeds, takeoffpower settings, and required field length should becomputed prior to each takeoff and recorded on atakeoff data card. These data will be based on airplaneweight, runway length available, runway gradient,field temperature, field barometric pressure, wind,icing conditions, and runway condition. Both pilotsshould separately compute the takeoff data andcross-check in the cockpit with the takeoff data card.

Ch 15.qxd 5/7/04 10:22 AM Page 15-16

15-17

A captain’s briefing is an essential part of cockpitresource management (CRM) procedures and shouldbe accomplished just prior to takeoff. [Figure 15-20]The captain’s briefing is an opportunity to review crew

coordination procedures for takeoff, which is alwaysthe most critical portion of a flight.

The takeoff and climb-out should be accomplished inaccordance with a standard takeoff and departureprofile developed for the particular make and modelairplane. [Figure 15-21]

TAKEOFF ROLLThe entire runway length should be available fortakeoff, especially if the pre-calculated takeoffperformance shows the airplane to be limited byrunway length or obstacles. After taxing into positionat the end of the runway, the airplane should be alignedin the center of the runway allowing equal distance oneither side. The brakes should be held while the thrustlevers are brought to a power setting beyond the bleedvalve range (normally the vertical position) and theengines allowed to stabilized. The engine instrumentsshould be checked for proper operation before thebrakes are released or the power increased further. Thisprocedure assures symmetrical thrust during thetakeoff roll and aids in preventing overshooting thedesired takeoff thrust setting. The brakes should thenbe released and, during the start of the takeoff roll, thethrust levers smoothly advanced to the pre-computedtakeoff power setting. All final takeoff thrustadjustments should be made prior to reaching 60 knots.The final engine power adjustments are normally madeby the pilot not flying. Once the thrust levers are set fortakeoff power, they should not be readjusted after 60knots. Retarding a thrust lever would only benecessary in case an engine exceeds any limitationsuch as ITT, fan, or turbine r.p.m.

CAPTAIN'S BRIEFING

I will advance the thrust levers.

Follow me through on the thrust levers.

Monitor all instruments and warning lights on the takeoff roll and call out any discrepancies or malfunctions observed prior to V1, and I will abort the takeoff. Stand by to arm thrust reversers on my command.

Give me a visual and oral signal for the following: • 80 knots, and I will disengage nosewheel steering. • V1, and I will move my hand from thrust to yoke. • VR, and I will rotate.

In the event of engine failure at or after V1, I will continue the takeoff roll to VR, rotate and establish V2 climb speed.I will identify the inoperative engine, and we will both verify. I will accomplish the shutdown, or have you do it on my command.

I will expect you to stand by on the appropriate emergency checklist.

I will give you a visual and oral signal for gear retraction and for power settings after the takeoff.

Our VFR emergency procedure is to.............................Our IFR emergency procedure is to..............................

Figure 15-20. Sample captain’s briefing.

• Set Takeoff Thrust Prior to 60 Knots• 70 Knots Check

• V1/VR• Rotate Smoothly to 10° Nose Up

• Positive Rate of Climb• Gear Up

• V2 + 10 Knots Minimum

Altitude Selected to Flap Retraction(400 Ft. FAA Minimum)(or Obstacle Clearance Altitude)

Close-In TurnMaintain: • Flaps T.O. & Appr. • V2 + 20 Knots Minimum • Maximum Bank 30°

Straight Climbout:• V2 + 10 Knots• Retract Flaps• Set Climb Thrust• Complete After-Takeoff Climb Checklist

Rollout:• V2 + 20 Minimum• Set Climb Thrust• Accelerate• Retract Flaps• Complete After-Takeoff Climb Checklist

NORMAL TAKEOFF

Figure 15-21.Takeoff and departure profile.

Ch 15.qxd 5/7/04 10:22 AM Page 15-17

15-18

If sufficient runway length is available, a “rolling”takeoff may be made without stopping at the end of therunway. Using this procedure, as the airplane rolls ontothe runway, the thrust levers should be smoothlyadvanced to the vertical position and the enginesallowed to stabilize, and then proceed as in the statictakeoff outlined above. Rolling takeoffs can also bemade from the end of the runway by advancing thethrust levers from idle as the brakes are released.

During the takeoff roll, the pilot flying shouldconcentrate on directional control of the airplane. Thisis made somewhat easier because there is no torque-produced yawing in a jet as there is in a propellerdriven airplane. The airplane must be maintainedexactly on centerline with the wings level. This willautomatically aid the pilot when contending with anengine failure. If a crosswind exists, the wings shouldbe kept level by displacing the control wheel into thecrosswind. During the takeoff roll, the primaryresponsibility of the pilot not flying is to closelymonitor the aircraft systems and to call out the properV speeds as directed in the captain’s briefing.

Slight forward pressure should be held on the controlcolumn to keep the nosewheel rolling firmly on therunway. If nosewheel steering is being utilized, thepilot flying should monitor the nosewheel steering toabout 80 knots (or VMCG for the particular airplane)while the pilot not flying applies the forward pressure.After reaching VMCG, the pilot flying should bringhis/her left hand up to the control wheel. The pilot’sother hand should be on the thrust levers until at leastV1 speed is attained. Although the pilot not flyingmaintains a check on the engine instrumentsthroughout the takeoff roll, the pilot flying (pilot incommand) makes the decision to continue or reject atakeoff for any reason. A decision to reject a takeoffwill require immediate retarding of thrust levers.

The pilot not flying should call out V1. After passingV1 speed on the takeoff roll, it is no longer mandatoryfor the pilot flying to keep a hand on the thrust levers.The point for abort has passed, and both hands may beplaced on the control wheel. As the airspeedapproaches VR, the control column should be moved toa neutral position. As the pre-computed VR speed isattained, the pilot not flying should make theappropriate callout and the pilot flying shouldsmoothly rotate the airplane to the appropriate takeoffpitch attitude.

ROTATION AND LIFT-OFFRotation and lift-off in a jet airplane should be consid-ered a maneuver unto itself. It requires planning, preci-sion, and a fine control touch. The objective is toinitiate the rotation to takeoff pitch attitude exactly atVR so that the airplane will accelerate through VLOF

and attain V2 speed at 35 feet at the end of the runway.Rotation to the proper takeoff attitude too soon mayextend the takeoff roll or cause an early lift-off, whichwill result in a lower rate of climb, and the predictedflightpath will not be followed. A late rotation, on theother hand, will result in a longer takeoff roll,exceeding V2 speed, and a takeoff and climb pathbelow the predicted path.

Each airplane has its own specific takeoff pitchattitude which remains constant regardless of weight.The takeoff pitch attitude in a jet airplane is normallybetween 10° and 15° nose up. The rotation to takeoffpitch attitude should be made smoothly butdeliberately, and at a constant rate. Depending on theparticular airplane, the pilot should plan on a rate ofpitch attitude increase of approximately 2.5° to 3° persecond.

In training it is common for the pilot to overshoot VRand then overshoot V2 because the pilot not flying willcall for rotation at, or just past VR. The reaction of thepilot flying is to visually verify VR and then rotate. Theairplane then leaves the ground at or above V2. Theexcess airspeed may be of little concern on a normaltakeoff, but a delayed rotation can be critical whenrunway length or obstacle clearance is limited. Itshould be remembered that on some airplanes, theall-engine takeoff can be more limiting than the engineout takeoff in terms of obstacle clearance in the initialpart of the climb-out. This is because of the rapidlyincreasing airspeed causing the achieved flightpath tofall below the engine out scheduled flightpath unlesscare is taken to fly the correct speeds. Thetransitioning pilot should remember that rotation at theright speed and rate to the right attitude will get theairplane off the ground at the right speed and withinthe right distance.

INITIAL CLIMBOnce the proper pitch attitude is attained, it must bemaintained. The initial climb after lift-off is done atthis constant pitch attitude. Takeoff power ismaintained and the airspeed allowed to accelerate.Landing gear retraction should be accomplished aftera positive rate of climb has been established andconfirmed. Remember that in some airplanes gearretraction may temporarily increase the airplane dragwhile landing gear doors open. Premature gearretraction may cause the airplane to settle backtowards the runway surface. Remember also thatbecause of ground effect, the vertical speed indicatorand the altimeter may not show a positive climb untilthe airplane is 35 to 50 feet above the runway.

The climb pitch attitude should continue to be held andthe airplane allowed to accelerate to flap retractionspeed. However, the flaps should not be retracted until

Ch 15.qxd 5/7/04 10:22 AM Page 15-18

15-19

obstruction clearance altitude or 400 feet AGL hasbeen passed. Ground effect and landing gear dragreduction results in rapid acceleration during this phaseof the takeoff and climb. Airspeed, altitude, climb rate,attitude, and heading must be monitored carefully.When the airplane settles down to a steady climb,longitudinal stick forces can be trimmed out. If a turnmust be made during this phase of flight, no more than15° to 20° of bank should be used. Because of spiralinstability, and because at this point an accurate trimstate on rudder and ailerons has not yet been achieved,the bank angle should be carefully monitored through-out the turn. If a power reduction must be made, pitchattitude should be reduced simultaneously and theairplane monitored carefully so as to preclude entryinto an inadvertent descent. When the airplane hasattained a steady climb at the appropriate en routeclimb speed, it can be trimmed about all axes and theautopilot engaged.

JET AIRPLANE APPROACH ANDLANDING

LANDING REQUIREMENTSThe FAA landing field length requirements for jetairplanes are specified in 14 CFR part 25. It defines theminimum field length (and therefore minimummargins) that can be scheduled. The regulationdescribes the landing profile as the distance requiredfrom a point 50 feet above the runway threshold,through the flare to touchdown, and then stoppingusing the maximum stopping capability on a dryrunway surface. The actual demonstrated distance isincreased by 67 percent and published in the FAA-approved Airplane Flight Manual as the FAR dryrunway landing distance. [Figure 15-22] For wetrunways, the FAR dry runway distance is increased byan additional 15 percent. Thus the minimum dryrunway field length will be 1.67 times the actualminimum air and ground distance needed and the wetrunway minimum landing field length will be 1.92

times the minimum dry air and ground distanceneeded.

Certified landing field length requirements arecomputed for the stop made with speed brakesdeployed and maximum wheel braking. Reverse thrustis not used in establishing the certified FAR landingdistances. However, reversers should definitely beused in service.

LANDING SPEEDSAs in the takeoff planning, there are certain speeds thatmust be taken into consideration during any landing ina jet airplane. The speeds are as follows.

• VSO—Stall speed in the landing configuration.

• VREF—1.3 times the stall speed in the landingconfiguration.

• Approach climb—The speed which guaranteesadequate performance in a go-around situationwith an inoperative engine. The airplane’s weightmust be limited so that a twin-engine airplanewill have a 2.1 percent climb gradient capability.(The approach climb gradient requirements for 3and 4 engine airplanes are 2.4 percent and 2.7percent respectively.) These criteria are based onan airplane configured with approach flaps, land-ing gear up, and takeoff thrust available from theoperative engine(s).

• Landing climb—The speed which guaranteesadequate performance in arresting the descentand making a go-around from the final stages oflanding with the airplane in the full landing con-figuration and maximum takeoff power availableon all engines.

The appropriate speeds should be pre-computed priorto every landing, and posted where they are visible toboth pilots. The VREF speed, or threshold speed, is used

VREF = 1.3 VS

TD50 Ft.

Actual Distance 60% 40%

FAR (Dry) Runway Field Length Required1.67 x Actual Distance

FAR (Wet) Runway Field Length Required1.15 x FAR (Dry)

or1.92 x Actual Distance

15%

Figure 15-22. FAR landing field length required.

Ch 15.qxd 5/7/04 10:22 AM Page 15-19

15-20

as a reference speed throughout the traffic pattern. Forexample:

Downwind leg—VREF plus 20 knots.

Base leg—VREF plus 10 knots.

Final approach—VREF plus 5 knots.

50 feet over threshold—VREF.

The approach and landing sequence in a jet airplaneshould be accomplished in accordance with anapproach and landing profile developed for the partic-ular airplane. [Figure 15-23]

SIGNIFICANT DIFFERENCESA safe approach in any type of airplane culminates in aparticular position, speed, and height over the runwaythreshold. That final flight condition is the targetwindow at which the entire approach aims. Propellerpowered airplanes are able to approach that target fromwider angles, greater speed differentials, and a largervariety of glidepath angles. Jet airplanes are not asresponsive to power and course corrections, so thefinal approach must be more stable, more deliberate,more constant, in order to reach the window accurately.

The transitioning pilot must understand that, in spiteof their impressive performance capabilities, there aresix ways in which a jet airplane is worse than a pistonengine airplane in making an approach and incorrecting errors on the approach.

• The absence of the propeller slipstream inproducing immediate extra lift at constantairspeed. There is no such thing as salvaging amisjudged glidepath with a sudden burst ofimmediately available power. Added lift canonly be achieved by accelerating the airframe.Not only must the pilot wait for added power buteven when the engines do respond, added liftwill only be available when the airframe hasresponded with speed.

• The absence of the propeller slipstream insignificantly lowering the power-on stall speed.There is virtually no difference between power-on and power-off stall speed. It is not possible ina jet airplane to jam the thrust levers forward toavoid a stall.

• Poor acceleration response in a jet engine fromlow r.p.m. This characteristic requires that theapproach be flown in a high drag/high power

1. Reset Bug to VREF

2. Review Airport Characteristics3. Complete Descent and Begin Before Landing Checklist

Abeam Runway Midpoint• Flaps T/O Approach• VREF + 20 Minimum

1500' AboveField Elevation

• Complete Before Landing Checklist• Maximum Bank 30°• Clear Final Approach

Rollout• Reduce Speed to VREF• Altitude Callouts• Stabilized in Slot

DO NOT MAKE FLATAPPROACH

Touchdown• Extend Speed Brake• Apply Brakes• Thrust reverser or Drag Chute as Required

Fly VREF

Abeam Touchdown Point• Gear Down

Turning Base• Flaps Land• Initially Set Fuel Flow to 400 Lb./Engine• Start Descent• VREF + 10 Minimum on Base

APPROACH PREPARATIONS

Figure 15-23.Typical approach and landing profile.

Ch 15.qxd 5/7/04 10:22 AM Page 15-20

15-21

configuration so that sufficient power will beavailable quickly if needed.

• The increased momentum of the jet airplanemaking sudden changes in the flightpathimpossible. Jet airplanes are consistently heavierthan comparable sized propeller airplanes. Thejet airplane, therefore, will require more indi-cated airspeed during the final approach due to awing design that is optimized for higher speeds.These two factors combine to produce highermomentum for the jet airplane. Since force isrequired to overcome momentum for speedchanges or course corrections, the jet will be farless responsive than the propeller airplane andrequire careful planning and stable conditionsthroughout the approach.

• The lack of good speed stability being aninducement to a low speed condition. The dragcurve for many jet airplanes is much flatter thanfor propeller airplanes, so speed changes do notproduce nearly as much drag change. Further, jetthrust remains nearly constant with small speedchanges. The result is far less speed stability.When the speed does increase or decrease, thereis little tendency for the jet airplane to re-acquirethe original speed. The pilot, therefore, mustremain alert to the necessity of making speedadjustments, and then make them aggressively inorder to remain on speed.

• Drag increasing faster than lift producing a highsink rate at low speeds. Jet airplane wingstypically have a large increase in drag in theapproach configuration. When a sink rate doesdevelop, the only immediate remedy is toincrease pitch attitude (angle of attack). Becausedrag increases faster than lift, that pitch changewill rapidly contribute to an even greater sinkrate unless a significant amount of power isaggressively applied.

These flying characteristics of jet airplanes make astabilized approach an absolute necessity.

THE STABILIZED APPROACHThe performance charts and the limitations containedin the FAA-approved Airplane Flight Manual arepredicated on momentum values that result fromprogrammed speeds and weights. Runway lengthlimitations assume an exact 50-foot threshold height atan exact speed of 1.3 times VSO. That “window” iscritical and is a prime reason for the stabilizedapproach. Performance figures also assume that oncethrough the target threshold window, the airplane willtouch down in a target touchdown zone approximately

1,000 feet down the runway, after which maximumstopping capability will be used.

There are five basic elements to the stabilizedapproach.

• The airplane should be in the landingconfiguration early in the approach. The landinggear should be down, landing flaps selected, trimset, and fuel balanced. Ensuring that these tasksare completed will help keep the number ofvariables to a minimum during the finalapproach.

• The airplane should be on profile beforedescending below 1,000 feet. Configuration,trim, speed, and glidepath should be at or nearthe optimum parameters early in the approach toavoid distractions and conflicts as the airplanenears the threshold window. An optimumglidepath angle of 2.5° to 3° should beestablished and maintained.

• Indicated airspeed should be within 10 knots ofthe target airspeed. There are strong relationshipsbetween trim, speed, and power in most jetairplanes and it is important to stabilize the speedin order to minimize those other variables.

• The optimum descent rate should be 500 to 700feet per minute. The descent rate should not beallowed to exceed 1,000 feet per minute at anytime during the approach.

• The engine speed should be at an r.p.m. thatallows best response when and if a rapid powerincrease is needed.

Every approach should be evaluated at 500 feet. In atypical jet airplane, this is approximately 1 minutefrom touchdown. If the approach is not stabilized atthat height, a go-around should be initiated. (Seefigure 15-24 on the next page.)

APPROACH SPEEDOn final approach, the airspeed is controlled withpower. Any speed diversion from VREF on finalapproach must be detected immediately and corrected.With experience the pilot will be able to detect the veryfirst tendency of an increasing or decreasing airspeedtrend, which normally can be corrected with a smalladjustment in thrust. The pilot must be attentive to poorspeed stability leading to a low speed condition withits attendant risk of high drag increasing the sink rate.Remember that with an increasing sink rate an appar-ently normal pitch attitude is no guarantee of a normalangle of attack value. If an increasing sink rate isdetected, it must be countered by increasing the angle

Ch 15.qxd 5/7/04 10:22 AM Page 15-21

15-22

of attack and simultaneously increasing thrust tocounter the extra drag. The degree of correctionrequired will depend on how much the sink rate needsto be reduced. For small amounts, smooth and gentle,almost anticipatory corrections will be sufficient. Forlarge sink rates, drastic corrective measures may berequired that, even if successful, would destabilizethe approach.

A common error in the performance of approaches injet airplanes is excess approach speed. Excessapproach speed carried through the threshold windowand onto the runway will increase the minimumstopping distance required by 20 – 30 feet per knot ofexcess speed for a dry runway and 40 – 50 feet for awet runway. Worse yet, the excess speed will increasethe chances of an extended flare, which will increasethe distance to touchdown by approximately 250 feetfor each excess knot in speed.

Proper speed control on final approach is of primaryimportance. The pilot must anticipate the need forspeed adjustment so that only small adjustments arerequired. It is essential that the airplane arrive at theapproach threshold window exactly on speed.

GLIDEPATH CONTROLOn final approach, at a constant airspeed, the glidepathangle and rate of descent is controlled with pitchattitude and elevator. The optimum glidepath angle is2.5° to 3° whether or not an electronic glidepathreference is being used. On visual approaches, pilotsmay have a tendency to make flat approaches. A flatapproach, however, will increase landing distance andshould be avoided. For example, an approach angle of

2° instead of a recommended 3° will add 500 feet tolanding distance.

A more common error is excessive height over thethreshold. This could be the result of an unstableapproach, or a stable but high approach. It also mayoccur during an instrument approach where the missedapproach point is close to or at the runway threshold.Regardless of the cause, excessive height over thethreshold will most likely result in a touchdownbeyond the normal aiming point. An extra 50 feet ofheight over the threshold will add approximately 1,000feet to the landing distance. It is essential that theairplane arrive at the approach threshold windowexactly on altitude (50 feet above the runway).

THE FLAREThe flare reduces the approach rate of descent to amore acceptable rate for touchdown. Unlike lightairplanes, a jet airplane should be flown onto therunway rather than “held off” the surface as speeddissipates. A jet airplane is aerodynamically cleaneven in the landing configuration, and its engines stillproduce residual thrust at idle r.p.m. Holding it offduring the flare in a attempt to make a smooth landingwill greatly increase landing distance. A firm landingis normal and desirable. A firm landing does not meana hard landing, but rather a deliberate or positivelanding.

For most airports, the airplane will pass over the endof the runway with the landing gear 30 – 45 feet abovethe surface, depending on the landing flap setting andthe location of the touchdown zone. It will take 5 – 7seconds from the time the airplane passes the end of

Figure 15-24. Stabilized approach.

Stop Rollout Touchdown

1,000'

ThresholdWindow

50' VREF

500'Window

Check forStabilizedApproach

Stabilized Approachon Course on Speed2.5° - 3° Glidepath

500 - 700 FPMDescent

1,000'Window

Flare

Ch 15.qxd 5/7/04 10:22 AM Page 15-22

15-23

the runway until touchdown. The flare is initiated byincreasing the pitch attitude just enough to reduce thesink rate to 100 – 200 feet per minute when the landinggear is approximately 15 feet above the runwaysurface. In most jet airplanes, this will require a pitchattitude increase of only 1° to 3°. The thrust issmoothly reduced to idle as the flare progresses.

The normal speed bleed off during the time betweenpassing the end of the runway and touchdown is 5knots. Most of the decrease occurs during the flarewhen thrust is reduced. If the flare is extended (heldoff) while an additional speed is bled off, hundreds oreven thousands of feet of runway may be used up.[Figure 15-25] The extended flare will also result inadditional pitch attitude which may lead to a tail strike.It is, therefore, essential to fly the airplane onto therunway at the target touchdown point, even if thespeed is excessive. A deliberate touchdown should beplanned and practiced on every flight. A positivetouchdown will help prevent an extended flare.

Pilots must learn the flare characteristics of each modelof airplane they fly. The visual reference cues observed

from each cockpit are different because windowgeometry and visibility are different. The geometricrelationship between the pilot’s eye and the landinggear will be different for each make and model. It isessential that the flare maneuver be initiated at theproper height—not too high and not too low.

Beginning the flare too high or reducing the thrust tooearly may result in the airplane floating beyond thetarget touchdown point or may include a rapid pitch upas the pilot attempts to prevent a high sink ratetouchdown. This can lead to a tail strike. The flare thatis initiated too late may result in a hard touchdown.

Proper thrust management through the flare is alsoimportant. In many jet airplanes, the engines produce anoticeable effect on pitch trim when the thrust settingis changed. A rapid change in the thrust setting requiresa quick elevator response. If the thrust levers aremoved to idle too quickly during the flare, the pilotmust make rapid changes in pitch control. If the thrustlevers are moved more slowly, the elevator input canbe more easily coordinated.

TouchdownOn Target

ExtendedFlare

10 Knots Decelerationon Ground (Maximum Braking)

10 Knots Decelerationin Flare

200 Ft. (Dry Runway)500 Ft. (Wet Runway)

2,000 Ft. (Air)

Figure 15-25. Extended flare.

Ch 15.qxd 5/7/04 10:22 AM Page 15-23

15-24

TOUCHDOWN AND ROLLOUTA proper approach and flare positions the airplane totouch down in the touchdown target zone, which isusually about 1,000 feet beyond the runway threshold.Once the main wheels have contacted the runway, thepilot must maintain directional control and initiate thestopping process. The stop must be made on therunway that remains in front of the airplane. Therunway distance available to stop is longest if thetouchdown was on target. The energy to be dissipatedis least if there is no excess speed. The stop that beginswith a touchdown that is on the numbers will be theeasiest stop to make for any set of conditions.

At the point of touchdown, the airplane represents avery large mass that is moving at a relatively highspeed. The large total energy must be dissipated by thebrakes, the aerodynamic drag, and the thrust reversers.The nosewheel should be flown onto the groundimmediately after touchdown because a jet airplanedecelerates poorly when held in a nose-high attitude.Placing the nosewheel tire(s) on the ground will assistin maintaining directional control. Also, lowering thenose gear decreases the wing angle of attack,decreasing the lift, placing more load onto the tires,thereby increasing tire-to-ground friction. Landingdistance charts for jet airplanes assume that thenosewheel is lowered onto the runway within 4seconds of touchdown.

There are only three forces available for stopping theairplane. They are wheel braking, reverse thrust, andaerodynamic braking. Of the three, the brakes are mosteffective and therefore the most important stoppingforce for most landings. When the runway is veryslippery, reverse thrust and drag may be the dominantforces. Both reverse thrust and aerodynamic drag aremost effective at high speeds. Neither is affected byrunway surface condition. Brakes, on the other hand,are most effective at low speed. The landing rolloutdistance will depend on the touchdown speed and whatforces are applied and when they are applied. The pilot

controls the what and when factors, but the maximumbraking force may be limited by tire-to-groundfriction.

The pilot should begin braking as soon aftertouchdown and wheel spin-up as possible, and tosmoothly continue the braking until stopped or a safetaxi speed is reached. However, caution should be usedif the airplane is not equipped with a functioninganti-skid system. In such a case, heavy braking cancause the wheels to lock and the tires to skid.

Both directional control and braking utilize tire groundfriction. They share the maximum friction force thetires can provide. Increasing either will subtract fromthe other. Understanding tire ground friction, howrunway contamination affects it, and how to use thefriction available to maximum advantage is importantto a jet pilot.

Spoilers should be deployed immediately aftertouchdown because they are most effective at highspeed. Timely deployment of spoilers will increasedrag by 50 to 60 percent, but more importantly, theyspoil much of the lift the wing is creating, therebycausing more of the weight of the airplane to be loadedonto the wheels. The spoilers increase wheel loadingby as much as 200 percent in the landing flapconfiguration. This increases the tire ground frictionforce making the maximum tire braking and corneringforces available.

Like spoilers, thrust reversers are most effective athigh speeds and should be deployed quickly aftertouchdown. However, the pilot should not commandsignificant reverse thrust until the nosewheel is on theground. Otherwise, the reversers might deployasymmetrically resulting in an uncontrollable yawtowards the side on which the most reverse thrust isbeing developed, in which case the pilot will needwhatever nosewheel steering is available to maintaindirectional control.

Ch 15.qxd 5/7/04 10:22 AM Page 15-24

16-1

EMERGENCY SITUATIONSThis chapter contains information on dealing withnon-normal and emergency situations that may occur inflight. The key to successful management of anemergency situation, and/or preventing a non-normalsituation from progressing into a true emergency, isa thorough familiarity with, and adherence to, theprocedures developed by the airplane manufacturer andcontained in the FAA-approved Airplane Flight Manualand/or Pilot’s Operating Handbook (AFM/POH). Thefollowing guidelines are generic and are not meant toreplace the airplane manufacturer’s recommendedprocedures. Rather, they are meant to enhance thepilot’s general knowledge in the area of non-normal andemergency operations. If any of the guidance in thischapter conflicts in any way with the manufacturer’srecommended procedures for a particular make andmodel airplane, the manufacturer’s recommendedprocedures take precedence.

EMERGENCY LANDINGSThis section contains information on emergency land-ing techniques in small fixed-wing airplanes. Theguidelines that are presented apply to the more adverseterrain conditions for which no practical training ispossible. The objective is to instill in the pilot theknowledge that almost any terrain can be considered“suitable” for a survivable crash landing if the pilotknows how to use the airplane structure for self-protectionand the protection of passengers.

TYPES OF EMERGENCY LANDINGSThe different types of emergency landings are definedas follows.

• Forced landing. An immediate landing, on or offan airport, necessitated by the inability to con-tinue further flight. A typical example of which isan airplane forced down by engine failure.

• Precautionary landing. A premeditated landing,on or off an airport, when further flight is possi-ble but inadvisable. Examples of conditions thatmay call for a precautionary landing includedeteriorating weather, being lost, fuel shortage,and gradually developing engine trouble.

• Ditching. A forced or precautionary landing onwater.

A precautionary landing, generally, is less hazardousthan a forced landing because the pilot has more timefor terrain selection and the planning of the approach.In addition, the pilot can use power to compensate forerrors in judgment or technique. The pilot should beaware that too many situations calling for a precaution-ary landing are allowed to develop into immediateforced landings, when the pilot uses wishful thinkinginstead of reason, especially when dealing with aself-inflicted predicament. The non-instrument ratedpilot trapped by weather, or the pilot facing imminentfuel exhaustion who does not give any thought to thefeasibility of a precautionary landing accepts anextremely hazardous alternative.

PSYCHOLOGICAL HAZARDSThere are several factors that may interfere with apilot’s ability to act promptly and properly when facedwith an emergency.

• Reluctance to accept the emergency situation.A pilot who allows the mind to become paralyzedat the thought that the airplane will be on theground, in a very short time, regardless of thepilot’s actions or hopes, is severely handicappedin the handling of the emergency. An unconsciousdesire to delay the dreaded moment may lead tosuch errors as: failure to lower the nose to main-tain flying speed, delay in the selection of themost suitable landing area within reach, andindecision in general. Desperate attempts tocorrect whatever went wrong, at the expense ofairplane control, fall into the same category.

• Desire to save the airplane. The pilot who hasbeen conditioned during training to expect to finda relatively safe landing area, whenever the flightinstructor closed the throttle for a simulatedforced landing, may ignore all basic rules ofairmanship to avoid a touchdown in terrain whereairplane damage is unavoidable. Typical con-sequences are: making a 180° turn back to therunway when available altitude is insufficient;stretching the glide without regard for minimumcontrol speed in order to reach a more appealingfield; accepting an approach and touchdownsituation that leaves no margin for error. Thedesire to save the airplane, regardless of the risksinvolved, may be influenced by two other factors:the pilot’s financial stake in the airplane and the

Ch 16.qxd 5/7/04 10:30 AM Page 16-1

16-2

certainty that an undamaged airplane implies nobodily harm. There are times, however, when apilot should be more interested in sacrificing theairplane so that the occupants can safely walkaway from it.

• Undue concern about getting hurt. Fear is avital part of the self-preservation mechanism.However, when fear leads to panic, we invite thatwhich we want most to avoid. The survivalrecords favor pilots who maintain their compo-sure and know how to apply the general conceptsand procedures that have been developed throughthe years. The success of an emergency landing isas much a matter of the mind as of skills.

BASIC SAFETY CONCEPTS

GENERALA pilot who is faced with an emergency landing in ter-rain that makes extensive airplane damage inevitableshould keep in mind that the avoidance of crashinjuries is largely a matter of: (1) keeping vitalstructure (cockpit/cabin area) relatively intact by usingdispensable structure (such as wings, landing gear, andfuselage bottom) to absorb the violence of the stoppingprocess before it affects the occupants, (2) avoidingforceful bodily contact with interior structure.

The advantage of sacrificing dispensable structure isdemonstrated daily on the highways. A head-on carimpact against a tree at 20 miles per hour (m.p.h.) isless hazardous for a properly restrained driver than asimilar impact against the driver’s door. Accidentexperience shows that the extent of crushable structurebetween the occupants and the principal point ofimpact on the airplane has a direct bearing on theseverity of the transmitted crash forces and, therefore,on survivability.

Avoiding forcible contact with interior structure is amatter of seat and body security. Unless the occupantdecelerates at the same rate as the surroundingstructure, no benefit will be realized from its relativeintactness. The occupant will be brought to a stop vio-lently in the form of a secondary collision.

Dispensable airplane structure is not the only availableenergy absorbing medium in an emergency situation.Vegetation, trees, and even manmade structures maybe used for this purpose. Cultivated fields with densecrops, such as mature corn and grain, are almost aseffective in bringing an airplane to a stop withrepairable damage as an emergency arresting deviceon a runway. [Figure 16-1] Brush and small treesprovide considerable cushioning and braking effectwithout destroying the airplane. When dealing withnatural and manmade obstacles with greater strengththan the dispensable airplane structure, the pilot must

plan the touchdown in such a manner that only non-essential structure is “used up” in the principalslowing down process.

The overall severity of a deceleration process isgoverned by speed (groundspeed) and stoppingdistance. The most critical of these is speed; doublingthe groundspeed means quadrupling the total destruc-tive energy, and vice versa. Even a small change ingroundspeed at touchdown—be it as a result of windor pilot technique—will affect the outcome of acontrolled crash. It is important that the actualtouchdown during an emergency landing be made atthe lowest possible controllable airspeed, using allavailable aerodynamic devices.

Most pilots will instinctively—and correctly—lookfor the largest available flat and open field for an emer-gency landing. Actually, very little stopping distanceis required if the speed can be dissipated uniformly;that is, if the deceleration forces can be spread evenlyover the available distance. This concept is designedinto the arresting gear of aircraft carriers that providesa nearly constant stopping force from the moment ofhookup.

The typical light airplane is designed to provideprotection in crash landings that expose the occupantsto nine times the acceleration of gravity (9 G) in aforward direction. Assuming a uniform 9 G decelera-tion, at 50 m.p.h. the required stopping distance isabout 9.4 feet. While at 100 m.p.h. the stopping dis-tance is about 37.6 feet—about four times as great.[Figure 16-2] Although these figures are based on anideal deceleration process, it is interesting to note whatcan be accomplished in an effectively used short stop-ping distance. Understanding the need for a firmbut uniform deceleration process in very poor terrainenables the pilot to select touchdown conditions thatwill spread the breakup of dispensable structure over ashort distance, thereby reducing the peak decelerationof the cockpit/cabin area.

Figure 16-1. Using vegetation to absorb energy.

Ch 16.qxd 5/7/04 10:30 AM Page 16-2

16-3

ATTITUDE AND SINK RATE CONTROLThe most critical and often the most inexcusable errorthat can be made in the planning and execution of anemergency landing, even in ideal terrain, is the loss ofinitiative over the airplane’s attitude and sink rate attouchdown. When the touchdown is made on flat, openterrain, an excessive nose-low pitch attitude brings therisk of “sticking” the nose in the ground. Steep bankangles just before touchdown should also be avoided,as they increase the stalling speed and the likelihood ofa wingtip strike.

Since the airplane’s vertical component of velocity willbe immediately reduced to zero upon ground contact, itmust be kept well under control. A flat touchdown at ahigh sink rate (well in excess of 500 feet per minute(f.p.m.)) on a hard surface can be injurious withoutdestroying the cockpit/cabin structure, especially duringgear up landings in low-wing airplanes. A rigid bottomconstruction of these airplanes may preclude adequatecushioning by structural deformation. Similar impactconditions may cause structural collapse of the overheadstructure in high-wing airplanes. On soft terrain, anexcessive sink rate may cause digging in of the lowernose structure and severe forward deceleration.

TERRAIN SELECTIONA pilot’s choice of emergency landing sites is governedby:

• The route selected during preflight planning.

• The height above the ground when the emergencyoccurs.

• Excess airspeed (excess airspeed can be con-verted into distance and/or altitude).

The only time the pilot has a very limited choice is dur-ing the low and slow portion of the takeoff. However,even under these conditions, the ability to change theimpact heading only a few degrees may ensure asurvivable crash.

If beyond gliding distance of a suitable open area, thepilot should judge the available terrain for its energyabsorbing capability. If the emergency starts at aconsiderable height above the ground, the pilot shouldbe more concerned about first selecting the desiredgeneral area than a specific spot. Terrain appearancesfrom altitude can be very misleading and considerablealtitude may be lost before the best spot can bepinpointed. For this reason, the pilot should nothesitate to discard the original plan for one that is obvi-ously better. However, as a general rule, the pilotshould not change his or her mind more than once; awell-executed crash landing in poor terrain can be lesshazardous than an uncontrolled touchdown on anestablished field.

AIRPLANE CONFIGURATIONSince flaps improve maneuverability at slow speed,and lower the stalling speed, their use during finalapproach is recommended when time and circum-stances permit. However, the associated increase indrag and decrease in gliding distance call for caution inthe timing and the extent of their application;premature use of flap, and dissipation of altitude,may jeopardize an otherwise sound plan.

A hard and fast rule concerning the position of aretractable landing gear at touchdown cannot be given.In rugged terrain and trees, or during impacts at highsink rate, an extended gear would definitely have aprotective effect on the cockpit/cabin area. However,this advantage has to be weighed against the possibleside effects of a collapsing gear, such as a ruptured fueltank. As always, the manufacturer’s recommendationsas outlined in the AFM/POH should be followed.

When a normal touchdown is assured, and ample stop-ping distance is available, a gear up landing on level, butsoft terrain, or across a plowed field, may result in lessairplane damage than a gear down landing. [Figure 16-3]

9g Deceleration

37.6 ft.

50 m.p.h. 100 m.p.h.

9.4 ft.

Figure 16-2. Stopping distance vs. groundspeed.

Figure 16-3. Intentional gear up landing.

Ch 16.qxd 5/7/04 10:30 AM Page 16-3

16-4

Deactivation of the airplane’s electrical system beforetouchdown reduces the likelihood of a post-crash fire.However, the battery master switch should not beturned off until the pilot no longer has any need forelectrical power to operate vital airplane systems.Positive airplane control during the final part of theapproach has priority over all other considerations,including airplane configuration and cockpit checks.The pilot should attempt to exploit the power availablefrom an irregularly running engine; however, it is gen-erally better to switch the engine and fuel off justbefore touchdown. This not only ensures the pilot’sinitiative over the situation, but a cooled down enginereduces the fire hazard considerably.

APPROACHWhen the pilot has time to maneuver, the planning ofthe approach should be governed by three factors.

• Wind direction and velocity.

• Dimensions and slope of the chosen field.

• Obstacles in the final approach path.

These three factors are seldom compatible. When com-promises have to be made, the pilot should aim for awind/obstacle/terrain combination that permits a finalapproach with some margin for error in judgment ortechnique. A pilot who overestimates the gliding rangemay be tempted to stretch the glide across obstacles inthe approach path. For this reason, it is sometimesbetter to plan the approach over an unobstructed area,regardless of wind direction. Experience shows that acollision with obstacles at the end of a ground roll, orslide, is much less hazardous than striking an obstacleat flying speed before the touchdown point is reached.

TERRAIN TYPESSince an emergency landing on suitable terrain resem-bles a situation in which the pilot should be familiarthrough training, only the more unusual situation willbe discussed.

CONFINED AREASThe natural preference to set the airplane down on theground should not lead to the selection of an open spotbetween trees or obstacles where the ground cannot bereached without making a steep descent.

Once the intended touchdown point is reached, and theremaining open and unobstructed space is very lim-ited, it may be better to force the airplane down on theground than to delay touchdown until it stalls (settles).An airplane decelerates faster after it is on the groundthan while airborne. Thought may also be given to thedesirability of ground-looping or retracting the landinggear in certain conditions.

A river or creek can be an inviting alternative in other-wise rugged terrain. The pilot should ensure that the

water or creek bed can be reached without snaggingthe wings. The same concept applies to road landingswith one additional reason for caution; manmadeobstacles on either side of a road may not be visibleuntil the final portion of the approach.

When planning the approach across a road, it shouldbe remembered that most highways, and even ruraldirt roads, are paralleled by power or telephone lines.Only a sharp lookout for the supporting structures, orpoles, may provide timely warning.

TREES (FOREST)Although a tree landing is not an attractive prospect,the following general guidelines will help to make theexperience survivable.

• Use the normal landing configuration (full flaps,gear down).

• Keep the groundspeed low by heading into thewind.

• Make contact at minimum indicated airspeed, butnot below stall speed, and “hang” the airplane inthe tree branches in a nose-high landing attitude.Involving the underside of the fuselage and bothwings in the initial tree contact provides a moreeven and positive cushioning effect, while pre-venting penetration of the windshield. [Figure16-4]

• Avoid direct contact of the fuselage with heavytree trunks.

• Low, closely spaced trees with wide, densecrowns (branches) close to the ground are muchbetter than tall trees with thin tops; the latterallow too much free fall height. (A free fall from75 feet results in an impact speed of about 40knots, or about 4,000 f.p.m.)

• Ideally, initial tree contact should be symmet-rical; that is, both wings should meet equalresistance in the tree branches. This distributionof the load helps to maintain proper airplaneattitude. It may also preclude the loss of onewing, which invariably leads to a more rapid andless predictable descent to the ground.

• If heavy tree trunk contact is unavoidable oncethe airplane is on the ground, it is best to involveboth wings simultaneously by directing the air-plane between two properly spaced trees. Do notattempt this maneuver, however, while stillairborne.

WATER (DITCHING) AND SNOWA well-executed water landing normally involves lessdeceleration violence than a poor tree landing or a

Ch 16.qxd 5/7/04 10:30 AM Page 16-4

16-5

touchdown on extremely rough terrain. Also anairplane that is ditched at minimum speed and in a nor-mal landing attitude will not immediately sink upontouchdown. Intact wings and fuel tanks (especiallywhen empty) provide floatation for at least severalminutes even if the cockpit may be just below thewater line in a high-wing airplane.

Loss of depth perception may occur when landing on awide expanse of smooth water, with the risk of flyinginto the water or stalling in from excessive altitude. Toavoid this hazard, the airplane should be “dragged in”when possible. Use no more than intermediate flaps onlow-wing airplanes. The water resistance of fullyextended flaps may result in asymmetrical flap failureand slowing of the airplane. Keep a retractable gear upunless the AFM/POH advises otherwise.

A landing in snow should be executed like a ditching,in the same configuration and with the same regard forloss of depth perception (white out) in reduced visibil-ity and on wide open terrain.

ENGINE FAILURE AFTER TAKEOFF(SINGLE-ENGINE)The altitude available is, in many ways, the controllingfactor in the successful accomplishment of an emer-gency landing. If an actual engine failure should occurimmediately after takeoff and before a safe maneuveringaltitude is attained, it is usually inadvisable to attemptto turn back to the field from where the takeoff wasmade. Instead, it is safer to immediately establish the

proper glide attitude, and select a field directly aheador slightly to either side of the takeoff path.

The decision to continue straight ahead is oftendifficult to make unless the problems involved inattempting to turn back are seriously considered. In thefirst place, the takeoff was in all probability made intothe wind. To get back to the takeoff field, a downwindturn must be made. This increases the groundspeed andrushes the pilot even more in the performance ofprocedures and in planning the landing approach.Secondly, the airplane will be losing considerablealtitude during the turn and might still be in a bankwhen the ground is contacted, resulting in the airplanecartwheeling (which would be a catastrophe for theoccupants, as well as the airplane). After turning down-wind, the apparent increase in groundspeed couldmislead the pilot into attempting to prematurely slowdown the airplane and cause it to stall. On the otherhand, continuing straight ahead or making a slight turnallows the pilot more time to establish a safe landingattitude, and the landing can be made as slowly aspossible, but more importantly, the airplane can belanded while under control.

Concerning the subject of turning back to the runwayfollowing an engine failure on takeoff, the pilot shoulddetermine the minimum altitude an attempt of such amaneuver should be made in a particular airplane.Experimentation at a safe altitude should give the pilotan approximation of height lost in a descending 180°turn at idle power. By adding a safety factor of about25 percent, the pilot should arrive at a practical deci-sion height. The ability to make a 180° turn does notnecessarily mean that the departure runway can bereached in a power-off glide; this depends on the wind,the distance traveled during the climb, the heightreached, and the glide distance of the airplane withoutpower. The pilot should also remember that a turn backto the departure runway may in fact require more thana 180° change in direction.

Consider the following example of an airplane whichhas taken off and climbed to an altitude of 300 feetAGL when the engine fails. [Figure 16-5 on nextpage]. After a typical 4 second reaction time, the pilotelects to turn back to the runway. Using a standard rate(3° change in direction per second) turn, it will take 1minute to turn 180°. At a glide speed of 65 knots, theradius of the turn is 2,100 feet, so at the completion ofthe turn, the airplane will be 4,200 feet to one side ofthe runway. The pilot must turn another 45° to head theairplane toward the runway. By this time the totalchange in direction is 225° equating to 75 seconds plusthe 4 second reaction time. If the airplane in a power-off glide descends at approximately 1,000 f.p.m., it

Figure 16-4.Tree landing.

Ch 16.qxd 5/7/04 10:30 AM Page 16-5

16-6

will have descended 1,316, feet placing it 1,016 feetbelow the runway.

EMERGENCY DESCENTSAn emergency descent is a maneuver for descendingas rapidly as possible to a lower altitude or to theground for an emergency landing. [Figure 16-6] Theneed for this maneuver may result from an uncontrol-lable fire, a sudden loss of cabin pressurization, or anyother situation demanding an immediate and rapiddescent. The objective is to descend the airplane assoon and as rapidly as possible, within the structurallimitations of the airplane. Simulated emergencydescents should be made in a turn to check for other airtraffic below and to look around for a possibleemergency landing area. A radio call announcingdescent intentions may be appropriate to alert otheraircraft in the area. When initiating the descent, a bankof approximately 30 to 45° should be established tomaintain positive load factors (“G” forces) on theairplane.

Emergency descent training should be performed asrecommended by the manufacturer, including the con-figuration and airspeeds. Except when prohibited bythe manufacturer, the power should be reduced to idle,and the propeller control (if equipped) should beplaced in the low pitch (or high revolutions per minute

(r.p.m.)) position. This will allow the propeller to actas an aerodynamic brake to help prevent an excessiveairspeed buildup during the descent. The landing gearand flaps should be extended as recommended by themanufacturer. This will provide maximum drag so thatthe descent can be made as rapidly as possible, with-out excessive airspeed. The pilot should not allow theairplane’s airspeed to pass the never-exceed speed(VNE), the maximum landing gear extended speed(VLE), or the maximum flap extended speed (VFE), asapplicable. In the case of an engine fire, a highairspeed descent could blow out the fire. However, theweakening of the airplane structure is a major concernand descent at low airspeed would place less stress onthe airplane. If the descent is conducted in turbulentconditions, the pilot must also comply with the designmaneuvering speed (VA) limitations. The descentshould be made at the maximum allowable airspeedconsistent with the procedure used. This will provideincreased drag and therefore the loss of altitude asquickly as possible. The recovery from an emergencydescent should be initiated at a high enough altitude toensure a safe recovery back to level flight or aprecautionary landing.

When the descent is established and stabilized duringtraining and practice, the descent should be terminated.

Figure 16-5. Turning back to the runway after engine failure.

4,480 Ft.

180°

225°

300 Ft. AGL

1,016 Ft.

Ch 16.qxd 5/7/04 10:30 AM Page 16-6

16-7

In airplanes with piston engines, prolonged practice ofemergency descents should be avoided to preventexcessive cooling of the engine cylinders.

IN-FLIGHT FIREA fire in flight demands immediate and decisive action.The pilot therefore must be familiar with the proceduresoutlined to meet this emergency contained in theAFM/POH for the particular airplane. For the purposesof this handbook, in-flight fires are classified as: in-flight engine fires, electrical fires, and cabin fires.

ENGINE FIREAn in-flight engine compartment fire is usually causedby a failure that allows a flammable substance such asfuel, oil or hydraulic fluid to come in contact with a hotsurface. This may be caused by a mechanical failure ofthe engine itself, an engine-driven accessory, adefective induction or exhaust system, or a brokenline. Engine compartment fires may also result frommaintenance errors, such as improperly installed/fas-tened lines and/or fittings resulting in leaks.

Engine compartment fires can be indicated by smokeand/or flames coming from the engine cowling area.They can also be indicated by discoloration, bubbling,and/or melting of the engine cowling skin in caseswhere flames and/or smoke is not visible to the pilot.By the time a pilot becomes aware of an in-flightengine compartment fire, it usually is well developed.Unless the airplane manufacturer directs otherwise inthe AFM/POH, the first step on discovering a fireshould be to shut off the fuel supply to the engine byplacing the mixture control in the idle cut off positionand the fuel selector shutoff valve to the OFF position.The ignition switch should be left ON in order to useup the fuel that remains in the fuel lines and com-ponents between the fuel selector/shutoff valve andthe engine. This procedure may starve the enginecompartment of fuel and cause the fire to die naturally.If the flames are snuffed out, no attempt should bemade to restart the engine.

If the engine compartment fire is oil-fed, as evidencedby thick black smoke, as opposed to a fuel-fed firewhich produces bright orange flames, the pilot shouldconsider stopping the propeller rotation by featheringor other means, such as (with constant-speed pro-pellers) placing the pitch control lever to the minimumr.p.m. position and raising the nose to reduce airspeeduntil the propeller stops rotating. This procedure willstop an engine-driven oil (or hydraulic) pump fromcontinuing to pump the flammable fluid which isfeeding the fire.

Some light airplane emergency checklists direct thepilot to shut off the electrical master switch. However,the pilot should consider that unless the fire is electricalin nature, or a crash landing is imminent, deactivatingthe electrical system prevents the use of panel radiosfor transmitting distress messages and will also causeair traffic control (ATC) to lose transponder returns.

Pilots of powerless single-engine airplanes are leftwith no choice but to make a forced landing. Pilots oftwin-engine airplanes may elect to continue the flightto the nearest airport. However, consideration must begiven to the possibility that a wing could be seriouslyimpaired and lead to structural failure. Even a brief butintense fire could cause dangerous structural damage.In some cases, the fire could continue to burn underthe wing (or engine cowling in the case of a single-engine airplane) out of view of the pilot. Enginecompartment fires which appear to have beenextinguished have been known to rekindle withchanges in airflow pattern and airspeed.

The pilot must be familiar with the airplane’s emer-gency descent procedures. The pilot must bear in mindthat:

• The airplane may be severely structurally dam-aged to the point that its ability to remain undercontrol could be lost at any moment.

• The airplane may still be on fire and susceptibleto explosion.

• The airplane is expendable and the only thing thatmatters is the safety of those on board.

ELECTRICAL FIRESThe initial indication of an electrical fire is usually thedistinct odor of burning insulation. Once an electricalfire is detected, the pilot should attempt to identify thefaulty circuit by checking circuit breakers, instruments,avionics, and lights. If the faulty circuit cannot be read-ily detected and isolated, and flight conditions permit,the battery master switch and alternator/generatorswitches should be turned off to remove the possiblesource of the fire. However, any materials which havebeen ignited may continue to burn.

Figure 16-6. Emergency descent.

Ch 16.qxd 5/7/04 10:30 AM Page 16-7

16-8

If electrical power is absolutely essential for the flight,an attempt may be made to identify and isolate thefaulty circuit by:

1. Turning the electrical master switch OFF.

2. Turning all individual electrical switches OFF.

3. Turning the master switch back ON.

4. Selecting electrical switches that were ON beforethe fire indication one at a time, permitting a shorttime lapse after each switch is turned on to checkfor signs of odor, smoke, or sparks.

This procedure, however, has the effect of recreatingthe original problem. The most prudent course ofaction is to land as soon as possible.

CABIN FIRECabin fires generally result from one of three sources:(1) careless smoking on the part of the pilot and/orpassengers; (2) electrical system malfunctions; (3)heating system malfunctions. A fire in the cabin pres-ents the pilot with two immediate demands: attackingthe fire, and getting the airplane safely on the groundas quickly as possible. A fire or smoke in the cabinshould be controlled by identifying and shutting downthe faulty system. In many cases, smoke may beremoved from the cabin by opening the cabin air vents.This should be done only after the fire extinguisher (ifavailable) is used. Then the cabin air control can beopened to purge the cabin of both smoke and fumes. Ifsmoke increases in intensity when the cabin air ventsare opened, they should be immediately closed. Thisindicates a possible fire in the heating system, nosecompartment baggage area (if so equipped), or that theincrease in airflow is feeding the fire.

On pressurized airplanes, the pressurization air systemwill remove smoke from the cabin; however, if thesmoke is intense, it may be necessary to either depres-surize at altitude, if oxygen is available for alloccupants, or execute an emergency descent.

In unpressurized single-engine and light twin-engineairplanes, the pilot can attempt to expel the smokefrom the cabin by opening the foul weather windows.These windows should be closed immediately if thefire becomes more intense. If the smoke is severe, thepassengers and crew should use oxygen masks if avail-able, and the pilot should initiate an immediatedescent. The pilot should also be aware that on someairplanes, lowering the landing gear and/or wing flapscan aggravate a cabin smoke problem.

FLIGHT CONTROLMALFUNCTION/FAILURE

TOTAL FLAP FAILUREThe inability to extend the wing flaps will necessitatea no-flap approach and landing. In light airplanes a no-flap approach and landing is not particularly difficultor dangerous. However, there are certain factors whichmust be considered in the execution of this maneuver. A no-flap landing requires substantially more runwaythan normal. The increase in required landing distancecould be as much as 50 percent.

When flying in the traffic pattern with the wing flapsretracted, the airplane must be flown in a relativelynose-high attitude to maintain altitude, as compared toflight with flaps extended. Losing altitude can be moreof a problem without the benefit of the drag normallyprovided by flaps. A wider, longer traffic pattern maybe required in order to avoid the necessity of diving tolose altitude and consequently building up excessiveairspeed.

On final approach, a nose-high attitude can make itdifficult to see the runway. This situation, if not antic-ipated, can result in serious errors in judgment ofheight and distance. Approaching the runway in arelatively nose-high attitude can also cause theperception that the airplane is close to a stall. This maycause the pilot to lower the nose abruptly and risktouching down on the nosewheel.

With the flaps retracted and the power reduced forlanding, the airplane is slightly less stable in the pitchand roll axes. Without flaps, the airplane will tend tofloat considerably during roundout. The pilot shouldavoid the temptation to force the airplane onto the run-way at an excessively high speed. Neither should thepilot flare excessively, because without flaps thismight cause the tail to strike the runway.

ASYMMETRIC (SPLIT) FLAPAn asymmetric “split” flap situation is one in whichone flap deploys or retracts while the other remains inposition. The problem is indicated by a pronouncedroll toward the wing with the least flap deflectionwhen wing flaps are extended/retracted.

The roll encountered in a split flap situation is coun-tered with opposite aileron. The yaw caused by theadditional drag created by the extended flap willrequire substantial opposite rudder, resulting in across-control condition. Almost full aileron may berequired to maintain a wings-level attitude, especiallyat the reduced airspeed necessary for approach andlanding. The pilot therefore should not attempt to land

Ch 16.qxd 5/7/04 10:30 AM Page 16-8

16-9

with a crosswind from the side of the deployed flap,because the additional roll control required to counter-act the crosswind may not be available.

The pilot must be aware of the difference in stallspeeds between one wing and the other in a split flapsituation. The wing with the retracted flap will stallconsiderably earlier than the wing with the deployedflap. This type of asymmetrical stall will result in anuncontrollable roll in the direction of the stalled (clean)wing. If altitude permits, a spin will result.

The approach to landing with a split flap conditionshould be flown at a higher than normal airspeed. Thepilot should not risk an asymmetric stall and subse-quent loss of control by flaring excessively. Rather, theairplane should be flown onto the runway so that thetouchdown occurs at an airspeed consistent with a safemargin above flaps-up stall speed.

LOSS OF ELEVATOR CONTROLIn many airplanes, the elevator is controlled by twocables: a “down” cable and an “up” cable. Normally,a break or disconnect in only one of these cables willnot result in a total loss of elevator control. In mostairplanes, a failed cable results in a partial loss ofpitch control. In the failure of the “up” elevator cable(the “down” elevator being intact and functional) thecontrol yoke will move aft easily but produce noresponse. Forward yoke movement, however, beyondthe neutral position produces a nosedown attitude.Conversely, a failure of the “down” elevator cable,forward movement of the control yoke produces noeffect. The pilot will, however, have partial control ofpitch attitude with aft movement.

When experiencing a loss of up-elevator control, thepilot can retain pitch control by:

• Applying considerable nose-up trim.

• Pushing the control yoke forward to attain andmaintain desired attitude.

• Increasing forward pressure to lower the nose andrelaxing forward pressure to raise the nose.

• Releasing forward pressure to flare for landing.

When experiencing a loss of down-elevator control,the pilot can retain pitch control by:

• Applying considerable nosedown trim.

• Pulling the control yoke aft to attain and maintainattitude.

• Releasing back pressure to lower the nose andincreasing back pressure to raise the nose.

• Increasing back pressure to flare for landing.

Trim mechanisms can be useful in the event of anin-flight primary control failure. For example, if thelinkage between the cockpit and the elevator fails inflight, leaving the elevator free to weathervane in thewind, the trim tab can be used to raise or lower theelevator, within limits. The trim tabs are not as effec-tive as normal linkage control in conditions such aslow airspeed, but they do have some positive effect—usually enough to bring about a safe landing.

If an elevator becomes jammed, resulting in a total lossof elevator control movement, various combinations ofpower and flap extension offer a limited amount ofpitch control. A successful landing under these condi-tions, however, is problematical.

LANDING GEAR MALFUNCTIONOnce the pilot has confirmed that the landing gear hasin fact malfunctioned, and that one or more gear legsrefuses to respond to the conventional or alternatemethods of gear extension contained in the AFM/POH,there are several methods that may be useful inattempting to force the gear down. One method is todive the airplane (in smooth air only) to VNE speed (redline on the airspeed indicator) and (within the limits ofsafety) execute a rapid pull up. In normal categoryairplanes, this procedure will create a 3.8 G load on thestructure, in effect making the landing gear weigh 3.8times normal. In some cases, this may force the land-ing gear into the down and locked position. Thisprocedure requires a fine control touch and good feelfor the airplane. The pilot must avoid exceeding thedesign stress limits of the airplane while attempting tolower the landing gear. The pilot must also avoid anaccelerated stall and possible loss of control whileattention is directed to solving the landing gearproblem.

Another method that has proven useful in some casesis to induce rapid yawing. After stabilizing at orslightly less than maneuvering speed (VA), the pilotshould alternately and aggressively apply rudder in onedirection and then the other in rapid sequence. Theresulting yawing action may cause the landing gear tofall into place.

If all efforts to extend the landing gear have failed, anda gear up landing is inevitable, the pilot should selectan airport with crash and rescue facilities. The pilotshould not hesitate to request that emergency equip-ment be standing by.

When selecting a landing surface, the pilot should con-sider that a smooth, hard-surface runway usuallycauses less damage than rough, unimproved grassstrips. A hard surface does, however, create sparks thatcan ignite fuel. If the airport is so equipped, the pilot

Ch 16.qxd 5/7/04 10:30 AM Page 16-9

16-10

can request that the runway surface be foamed. Thepilot should consider burning off excess fuel. This willreduce landing speed and fire potential.

If the landing gear malfunction is limited to one mainlanding gear leg, the pilot should consume as muchfuel from that side of the airplane as practicable,thereby reducing the weight of the wing on that side.The reduced weight makes it possible to delay theunsupported wing from contacting the surface duringthe landing roll until the last possible moment.Reduced impact speeds result in less damage.

If only one landing gear leg fails to extend, the pilothas the option of landing on the available gear legs, orlanding with all the gear legs retracted. Landing ononly one main gear usually causes the airplane to veerstrongly in the direction of the faulty gear leg aftertouchdown. If the landing runway is narrow, and/orditches and obstacles line the runway edge, maximumdirectional control after touchdown is a necessity. Inthis situation, a landing with all three gear retractedmay be the safest course of action.

If the pilot elects to land with one main gear retracted(and the other main gear and nose gear down andlocked), the landing should be made in a nose-highattitude with the wings level. As airspeed decays, thepilot should apply whatever aileron control is neces-sary to keep the unsupported wing airborne as long aspossible. [Figure 16-7] Once the wing contacts thesurface, the pilot can anticipate a strong yaw in thatdirection. The pilot must be prepared to use fullopposite rudder and aggressive braking to maintainsome degree of directional control.

When landing with a retracted nosewheel (and themain gear extended and locked) the pilot should holdthe nose off the ground until almost full up-elevatorhas been applied. [Figure 16-8] The pilot should thenrelease back pressure in such a manner that the nosesettles slowly to the surface. Applying and holding fullup-elevator will result in the nose abruptly dropping tothe surface as airspeed decays, possibly resulting inburrowing and/or additional damage. Brake pressureshould not be applied during the landing roll unlessabsolutely necessary to avoid a collision with obstacles.

If the landing must be made with only the nose gearextended, the initial contact should be made on the aftfuselage structure with a nose-high attitude. Thisprocedure will help prevent porpoising and/or wheel-barrowing. The pilot should then allow the nosewheelto gradually touch down, using nosewheel steering asnecessary for directional control.

SYSTEMS MALFUNCTIONS

ELECTRICAL SYSTEMThe loss of electrical power can deprive the pilot ofnumerous critical systems, and therefore should notbe taken lightly even in day/VFR conditions. Mostin-flight failures of the electrical system are locatedin the generator or alternator. Once the generator oralternator system goes off line, the electrical sourcein a typical light airplane is a battery. If a warninglight or ammeter indicates the probability of an alter-nator or generator failure in an airplane with only onegenerating system, however, the pilot may have verylittle time available from the battery.

The rating of the airplane battery provides a clue to howlong it may last. With batteries, the higher the amperageload, the less the usable total amperage. Thus a 25-amphour battery could produce 5 amps per hour for 5 hours,but if the load were increased to 10 amps, it might lastonly 2 hours. A 40-amp load might discharge the batteryfully in about 10 or 15 minutes. Much depends on thebattery condition at the time of the system failure. If thebattery has been in service for a few years, its power maybe reduced substantially because of internal resistance.Or if the system failure was not detected immediately,much of the stored energy may have already been used. Itis essential, therefore, that the pilot immediately shednon-essential loads when the generating source fails.[Figure 16-9] The pilot should then plan to land at thenearest suitable airport.

What constitutes an “emergency” load following agenerating system failure cannot be predetermined,because the actual circumstances will always besomewhat different—for example, whether the flightis VFR or IFR, conducted in day or at night, in cloudsor in the clear. Distance to nearest suitable airport canalso be a factor.

Figure 16-7. Landing with one main gear retracted.

Figure 16-8. Landing with nosewheel retracted.

Ch 16.qxd 5/7/04 10:30 AM Page 16-10

16-11

The pilot should remember that the electrically powered(or electrically selected) landing gear and flaps will notfunction properly on the power left in a partiallydepleted battery. Landing gear and flap motors use uppower at rates much greater than most other types ofelectrical equipment. The result of selecting thesemotors on a partially depleted battery may well result inan immediate total loss of electrical power.

If the pilot should experience a complete in-flight lossof electrical power, the following steps should betaken:

• Shed all but the most necessary electrically-driven equipment.

• Understand that any loss of electrical power iscritical in a small airplane—notify ATC of the sit-uation immediately. Request radar vectors for alanding at the nearest suitable airport.

• If landing gear or flaps are electrically controlledor operated, plan the arrival well ahead of time.Expect to make a no-flap landing, and anticipatea manual landing gear extension.

PITOT-STATIC SYSTEMThe source of the pressure for operating the airspeedindicator, the vertical speed indicator, and the altimeteris the pitot-static system. The major components of thepitot-static system are the impact pressure chamberand lines, and the static pressure chamber and lines,each of which are subject to total or partial blockageby ice, dirt, and/or other foreign matter. Blockage ofthe pitot-static system will adversely affect instrumentoperation. [Figure 16-10 on next page]

Partial static system blockage is insidious in that itmay go unrecognized until a critical phase of flight.During takeoff, climb, and level-off at cruise altitudethe altimeter, airspeed indicator, and vertical speedindicator may operate normally. No indication ofmalfunction may be present until the airplane beginsa descent.

If the static reference system is severely restricted, butnot entirely blocked, as the airplane descends, thestatic reference pressure at the instruments begins tolag behind the actual outside air pressure. Whiledescending, the altimeter may indicate that the airplaneis higher than actual because the obstruction slows theairflow from the static port to the altimeter. Thevertical speed indicator confirms the altimeter’s infor-mation regarding rate of change, because the referencepressure is not changing at the same rate as the outsideair pressure. The airspeed indicator, unable to tellwhether it is experiencing more airspeed pitot pressureor less static reference pressure, indicates a higherairspeed than actual. To the pilot, the instrumentsindicate that the airplane is too high, too fast, anddescending at a rate much less than desired.

If the pilot levels off and then begins a climb, thealtitude indication may still lag. The vertical speedindicator will indicate that the airplane is not climbingas fast as actual. The indicated airspeed, however, maybegin to decrease at an alarming rate. The least amountof pitch-up attitude may cause the airspeed needle toindicate dangerously near stall speed.

Managing a static system malfunction requires that thepilot know and understand the airplane’s pitot-staticsystem. If a system malfunction is suspected, the pilotshould confirm it by opening the alternate staticsource. This should be done while the airplane isclimbing or descending. If the instrument needlesmove significantly when this is done, a static pressureproblem exists and the alternate source should be usedduring the remainder of the flight.

ABNORMAL ENGINE INSTRUMENTINDICATIONSThe AFM/POH for the specific airplane contains infor-mation that should be followed in the event of any

A. Continuous Load

Pitot Heating (Operating)Wingtip LightsHeater Igniter**Navigation Receivers**Communications ReceiversFuel IndicatorInstrument Lights (overhead)Engine IndicatorCompass LightLanding Gear IndicatorFlap Indicator

B. Intermittent Load

StarterLanding LightsHeater Blower MotorFlap MotorLanding Gear MotorCigarette LighterTransceiver (keyed)Fuel Boost PumpCowl Flap MotorStall Warning Horn

** Amperage for radios varies with equipment. In general, the more recent the model, the less amperage required.NOTE: Panel and indicator lights usually draw less than one amp.

141

1-41-2121111

1211111111

3.303.001-20

1-2 each1-2 each

0.400.600.300.200.170.17

100.0017.8014.0013.0010.007.505-72.001.001.50

Electrical Loads forLight Single

Numberof Units

TotalAmperes

Figure 16-9. Electrical load for light single.

Ch 16.qxd 5/7/04 10:30 AM Page 16-11

16-12

abnormal engine instrument indications. The table onthe next page offers generic information on some ofthe more commonly experienced in-flight abnormalengine instrument indications, their possible causes,and corrective actions. [Table 1]

DOOR OPENING IN FLIGHTIn most instances, the occurrence of an inadvertentdoor opening is not of great concern to the safety of aflight, but rather, the pilot’s reaction at the moment theincident happens. A door opening in flight may beaccompanied by a sudden loud noise, sustained noiselevel and possible vibration or buffeting. If a pilotallows himself or herself to become distracted to thepoint where attention is focused on the open doorrather than maintaining control of the airplane, loss ofcontrol may result, even though disruption of airflowby the door is minimal.

In the event of an inadvertent door opening in flight oron takeoff, the pilot should adhere to the following.

• Concentrate on flying the airplane. Particularly inlight single- and twin-engine airplanes; a cabindoor that opens in flight seldom if ever compro-mises the airplane’s ability to fly. There may besome handling effects such as roll and/or yaw, butin most instances these can be easily overcome.

• If the door opens after lift-off, do not rush to land.Climb to normal traffic pattern altitude, fly a nor-mal traffic pattern, and make a normal landing.

• Do not release the seat belt and shoulder harnessin an attempt to reach the door. Leave the dooralone. Land as soon as practicable, and close thedoor once safely on the ground.

• Remember that most doors will not stay wideopen. They will usually bang open, then settlepartly closed. A slip towards the door may causeit to open wider; a slip away from the door maypush it closed.

• Do not panic. Try to ignore the unfamiliar noiseand vibration. Also, do not rush. Attempting toget the airplane on the ground as quickly as pos-sible may result in steep turns at low altitude.

• Complete all items on the landing checklist.

• Remember that accidents are almost nevercaused by an open door. Rather, an open dooraccident is caused by the pilot’s distraction orfailure to maintain control of the airplane.

INADVERTENT VFR FLIGHT INTO IMC

GENERALIt is beyond the scope of this handbook to incorpo-rate a course of training in basic attitude instrumentflying. This information is contained in FAA-H-8083-15, Instrument Flying Handbook. Certainpilot certificates and/or associated ratings requiretraining in instrument flying and a demonstration ofspecific instrument flying tasks on the practical test.

Effect of BlockedPitot/Static

Sources on Airspeed,Altimeter and

Vertical Speed Indications

Pitot Source Blocked

One StaticSource Blocked

Both StaticSources Blocked

Both Static andPitot Sources Blocked

Increases with altitudegain; decreases

with altitude loss.

Decreases with altitudegain; increases

with altitude loss.

Unaffected Unaffected

Does not changewith actual gain or

loss of altitude.

Does not changewith actual variations

in vertical speed.

Inaccurate while sideslipping; very sensitive in turbulence.

All indications remain constant, regardless of actual changesin airspeed, altitude and vertical speed.

Indicated Airspeed Indicated AltitudeIndicated

Vertical Speed

Figure 16-10. Effects of blocked pitot-static sources.

Ch 16.qxd 5/7/04 10:30 AM Page 16-12

16-13

Pilots and flight instructors should refer to FAA-H-8083-15 for guidance in the performance of thesetasks, and to the appropriate practical test standardsfor information on the standards to which theserequired tasks must be performed for the particularcertificate level and/or rating. The pilot shouldremember, however, that unless these tasks are prac-ticed on a continuing and regular basis, skill erosionbegins almost immediately. In a very short time, thepilot’s assumed level of confidence will be muchhigher than the performance he or she will actuallybe able to demonstrate should the need arise.

Accident statistics show that the pilot who has notbeen trained in attitude instrument flying, or onewhose instrument skills have eroded, will lose con-trol of the airplane in about 10 minutes once forcedto rely solely on instrument reference. The purposeof this section is to provide guidance on practicalemergency measures to maintain airplane control fora limited period of time in the event a VFR pilotencounters IMC conditions. The main goal is notprecision instrument flying; rather, it is to help theVFR pilot keep the airplane under adequate controluntil suitable visual references are regained.

MALFUNCTION PROBABLE CAUSE CORRECTIVE ACTIONLoss of r.p.m. during cruise flight(non-altitude engines)

Carburetor or induction icing or air filterclogging

Apply carburetor heat. If dirty filter issuspected and non-filtered air is available,switch selector to unfiltered position.

Loss of manifold pressure during cruiseflight

Same as above Same as above.

Turbocharger failure Possible exhaust leak. Shut down engineor use lowest practicable power setting.Land as soon as possible.

Gain of manifold pressure during cruise flight

Throttle has opened, propeller control hasdecreased r.p.m., or improper method ofpower reduction

Readjust throttle and tighten friction lock.Reduce manifold pressure prior toreducing r.p.m.

High oil temperature Oil congealed in cooler Reduce power. Land. Preheat engine.Inadequate engine cooling Reduce power. Increase airspeed.Detonation or preignition Observe cylinder head temperatures for

high reading. Reduce manifold pressure.Enrich mixture.

Forth coming internal engine faiure Land as soon as possible or featherpropeller and stop engine.

Land as soon as possible or featherpropeller and stop engine.

Defective thermostatic oil cooler control Land as soon as possible. Consultmaintenance personnel.

Low oil temperature Engine not warmed up to operatingtemperature

Warm engine in prescribed manner.

High oil pressure Cold oil Same as above.

Same as above.

Same as above.

Same as above.

Same as above.Same as above.

Possible internal plugging Reduce power. Land as soon as possible.Low oil pressure Broken pressure relief valve

Insufficient oilBurned out bearings

Fluctuating oil pressure Low oil supply, loose oil lines, defectivepressure relief valveImproper cowl flap adjustment Adjust cowl flaps.

Adjust cowl flaps.

Insufficient airspeed for cooling Increase airspeed.Improper mixture adjustment Adjust mixture.Detonation or preignition Reduce power, enrich mixture, increase

cooling airflow.Low cylinder head temperature

High cylinder head temperature

Excessive cowl flap openingExcessively rich mixture Adjust mixture control.Exteneded glides without clearing engine Clear engine long enough to keep

temperatures at minimum range.Ammeter indicating discharge Alternator or generator failure Shed unnecessary electrical load. Land

as soon as practicable.Load meter indicating zero Same as aboveSurging r.p.m. and overspeeding Defective propeller

Defective propeller governor

Adjust propeller r.p.m.Defective engine Consult maintenance.

Consult maintenance personnel.

Consult maintenance.

Adjust propeller control. Attempt torestore normal operation.

Defective tachometerImproper mixture setting Readjust mixture for smooth operation.

Adjust mixture for smooth operation.

Loss of airspeed in cruise flight withmanifold pressure and r.p.m. constant

Possible loss of one or more cylinders Land as soon as possible.

Rough running engine Improper mixture control settingDefective ignition or valvesDetonation or preignition Reduce power, enrich mixture, open cowl

flaps to reduce cylinder head temp. Landas soon as practicable.

Induction air leak Reduce power. Consult maintenance.Plugged fuel nozzle (Fuel injection)Excessive fuel pressure or fuel flow Lean mixture control.

Loss of fuel pressure Engine driven pump failure Turn on boost tanks.No fuel Switch tanks, turn on fuel.

Table 1.

Ch 16.qxd 5/7/04 10:30 AM Page 16-13

16-14

The first steps necessary for surviving an encounterwith instrument meteorological conditions (IMC) by aVFR pilot are:

• Recognition and acceptance of the seriousness ofthe situation and the need for immediate remedialaction.

• Maintaining control of the airplane.

• Obtaining the appropriate assistance in getting theairplane safely on the ground.

RECOGNITIONA VFR pilot is in IMC conditions anytime he or she isunable to maintain airplane attitude control by referenceto the natural horizon, regardless of the circumstancesor the prevailing weather conditions. Additionally, theVFR pilot is, in effect, in IMC anytime he or she is inad-vertently, or intentionally for an indeterminate period oftime, unable to navigate or establish geographicalposition by visual reference to landmarks on thesurface. These situations must be accepted by the pilotinvolved as a genuine emergency, requiring appropriateaction.

The pilot must understand that unless he or she istrained, qualified, and current in the control of an air-plane solely by reference to flight instruments, he or shewill be unable to do so for any length of time. Manyhours of VFR flying using the attitude indicator as areference for airplane control may lull a pilot into a falsesense of security based on an overestimation of his orher personal ability to control the airplane solely byinstrument reference. In VFR conditions, even thoughthe pilot thinks he or she is controlling the airplane byinstrument reference, the pilot also receives an overviewof the natural horizon and may subconsciously rely on itmore than the cockpit attitude indicator. If the naturalhorizon were to suddenly disappear, the untrainedinstrument pilot would be subject to vertigo, spatialdisorientation, and inevitable control loss.

MAINTAINING AIRPLANE CONTROLOnce the pilot recognizes and accepts the situation, heor she must understand that the only way to control theairplane safely is by using and trusting the flight instru-ments. Attempts to control the airplane partially byreference to flight instruments while searching outsidethe cockpit for visual confirmation of the informationprovided by those instruments will result in inadequateairplane control. This may be followed by spatialdisorientation and complete control loss.

The most important point to be stressed is that the pilotmust not panic. The task at hand may seem over-whelming, and the situation may be compounded byextreme apprehension. The pilot therefore must makea conscious effort to relax.

The pilot must understand the most important con-cern—in fact the only concern at this point—is to keepthe wings level. An uncontrolled turn or bank usuallyleads to difficulty in achieving the objectives of anydesired flight condition. The pilot will find that goodbank control has the effect of making pitch controlmuch easier.

The pilot should remember that a person cannot feelcontrol pressures with a tight grip on the controls.Relaxing and learning to “control with the eyes andthe brain” instead of only the muscles, usually takesconsiderable conscious effort.

The pilot must believe what the flight instrumentsshow about the airplane’s attitude regardless of whatthe natural senses tell. The vestibular sense (motionsensing by the inner ear) can and will confuse the pilot.Because of inertia, the sensory areas of the inner earcannot detect slight changes in airplane attitude, norcan they accurately sense attitude changes which occurat a uniform rate over a period of time. On the otherhand, false sensations are often generated, leading thepilot to believe the attitude of the airplane has changedwhen, in fact, it has not. These false sensations resultin the pilot experiencing spatial disorientation.

ATTITUDE CONTROLAn airplane is, by design, an inherently stable platformand, except in turbulent air, will maintain approx-imately straight-and-level flight if properly trimmedand left alone. It is designed to maintain a state ofequilibrium in pitch, roll, and yaw. The pilot must beaware, however, that a change about one axis willaffect the stability of the others. The typical lightairplane exhibits a good deal of stability in the yawaxis, slightly less in the pitch axis, and even lesser stillin the roll axis. The key to emergency airplane attitudecontrol, therefore, is to:

• Trim the airplane with the elevator trim so that itwill maintain hands-off level flight at cruise air-speed.

• Resist the tendency to over control the airplane.Fly the attitude indicator with fingertip control.No attitude changes should be made unless theflight instruments indicate a definite need for achange.

• Make all attitude changes smooth and small, yetwith positive pressure. Remember that a smallchange as indicated on the horizon bar corre-sponds to a proportionately much larger changein actual airplane attitude.

• Make use of any available aid in attitude controlsuch as autopilot or wing leveler.

Ch 16.qxd 5/7/04 10:30 AM Page 16-14

16-15

The primary instrument for attitude control is the atti-tude indicator. [Figure 16-11] Once the airplane istrimmed so that it will maintain hands-off level flightat cruise airspeed, that airspeed need not vary until theairplane must be slowed for landing. All turns, climbsand descents can and should be made at this airspeed.Straight flight is maintained by keeping the wings levelusing “fingertip pressure” on the control wheel. Anypitch attitude change should be made by using no morethan one bar width up or down.

TURNSTurns are perhaps the most potentially dangerousmaneuver for the untrained instrument pilot for tworeasons.

• The normal tendency of the pilot to over control,leading to steep banks and the possibility of a“graveyard spiral.”

• The inability of the pilot to cope with the instabil-ity resulting from the turn.

When a turn must be made, the pilot must anticipateand cope with the relative instability of the roll axis.The smallest practical bank angle should be used—inany case no more than 10° bank angle. [Figure 16-12]A shallow bank will take very little vertical lift fromthe wings resulting in little if any deviation in altitude.It may be helpful to turn a few degrees and then returnto level flight, if a large change in heading must bemade. Repeat the process until the desired heading isreached. This process may relieve the progressiveoverbanking that often results from prolonged turns.

CLIMBSIf a climb is necessary, the pilot should raise theminiature airplane on the attitude indicator no more

than one bar width and apply power. [Figure 16-13]The pilot should not attempt to attain a specific climbspeed but accept whatever speed results. The objec-tive is to deviate as little as possible from level flightattitude in order to disturb the airplane’s equilibriumas little as possible. If the airplane is properlytrimmed, it will assume a nose-up attitude on its owncommensurate with the amount of power applied.Torque and P-factor will cause the airplane to have a

Figure 16-11. Attitude indicator.

Figure 16-12. Level turn.

Figure 16-13. Level climb.

Ch 16.qxd 5/7/04 10:30 AM Page 16-15

16-16

tendency to bank and turn to the left. This must beanticipated and compensated for. If the initial powerapplication results in an inadequate rate of climb,power should be increased in increments of 100 r.p.m.or 1 inch of manifold pressure until the desired rate ofclimb is attained. Maximum available power isseldom necessary. The more power used the more theairplane will want to bank and turn to the left.Resuming level flight is accomplished by firstdecreasing pitch attitude to level on the attitudeindicator using slow but deliberate pressure, allowingairspeed to increase to near cruise value, and thendecreasing power.

DESCENTSDescents are very much the opposite of the climbprocedure if the airplane is properly trimmed forhands-off straight-and-level flight. In this configura-tion, the airplane requires a certain amount of thrust tomaintain altitude. The pitch attitude is controlling theairspeed. The engine power, therefore, (translated intothrust by the propeller) is maintaining the selectedaltitude. Following a power reduction, however slight,there will be an almost imperceptible decrease inairspeed. However, even a slight change in speedresults in less down load on the tail, whereupon thedesigned nose heaviness of the airplane causes it topitch down just enough to maintain the airspeed forwhich it was trimmed. The airplane will then descendat a rate directly proportionate to the amount of thrustthat has been removed. Power reductions should bemade in increments of 100 r.p.m. or 1 inch of manifoldpressure and the resulting rate of descent should neverexceed 500 f.p.m. The wings should be held level onthe attitude indicator, and the pitch attitude should notexceed one bar width below level. [Figure 16-14]

COMBINED MANEUVERSCombined maneuvers, such as climbing or descendingturns should be avoided if at all possible by anuntrained instrument pilot already under the stress ofan emergency situation. Combining maneuvers willonly compound the problems encountered in individualmaneuvers and increase the risk of control loss.Remember that the objective is to maintain airplanecontrol by deviating as little as possible from straight-and-level flight attitude and thereby maintaining asmuch of the airplane’s natural equilibrium as possible.

When being assisted by air traffic controllers from theground, the pilot may detect a sense of urgency as heor she is being directed to change heading and/or alti-tude. This sense of urgency reflects a normal concernfor safety on the part of the controller. But the pilotmust not let this prompt him or her to attempt a maneuverthat could result in loss of control.

TRANSITION TO VISUAL FLIGHTOne of the most difficult tasks a trained and qualifiedinstrument pilot must contend with is the transitionfrom instrument to visual flight prior to landing. Forthe untrained instrument pilot, these difficulties aremagnified.

The difficulties center around acclimatization andorientation. On an instrument approach the trainedinstrument pilot must prepare in advance for thetransition to visual flight. The pilot must have amental picture of what he or she expects to see oncethe transition to visual flight is made and quicklyacclimatize to the new environment. Geographicalorientation must also begin before the transition as thepilot must visualize where the airplane will be in rela-tion to the airport/runway when the transition occursso that the approach and landing may be completed byvisual reference to the ground.

In an ideal situation the transition to visual flight ismade with ample time, at a sufficient altitude aboveterrain, and to visibility conditions sufficient toaccommodate acclimatization and geographicalorientation. This, however, is not always the case. Theuntrained instrument pilot may find the visibility stilllimited, the terrain completely unfamiliar, and altitudeabove terrain such that a “normal” airport trafficpattern and landing approach is not possible.Additionally, the pilot will most likely be underconsiderable self-induced psychological pressure to

Figure 16-14. Level descent.

Ch 16.qxd 5/7/04 10:30 AM Page 16-16

16-17

get the airplane on the ground. The pilot must take thisinto account and, if possible, allow time to becomeacclimatized and geographically oriented before

attempting an approach and landing, even if it meansflying straight and level for a time or circling theairport. This is especially true at night.

Ch 16.qxd 5/7/04 10:30 AM Page 16-17

16-18

Ch 16.qxd 5/7/04 10:30 AM Page 16-18

100-HOUR INSPECTION—An inspection, identical in scope to anannual inspection. Must be conductedevery 100 hours of flight on aircraft ofunder 12,500 pounds that are usedfor hire.

ABSOLUTE ALTITUDE—The vertical distance of an airplaneabove the terrain, or above groundlevel (AGL).

ABSOLUTE CEILING—The altitude at which a climb is nolonger possible.

ACCELERATE-GO DISTANCE—The distance required to accelerate toV1 with all engines at takeoff power,experience an engine failure at V1 andcontinue the takeoff on the remainingengine(s). The runway requiredincludes the distance required toclimb to 35 feet by which time V2

speed must be attained.

ACCELERATE-STOPDISTANCE—The distance requiredto accelerate to V1 with all engines attakeoff power, experience an enginefailure at V1, and abort the takeoff andbring the airplane to a stop using brak-ing action only (use of thrust revers-ing is not considered).

ACCELERATION—Force involvedin overcoming inertia, and which maybe defined as a change in velocity perunit of time.

ACCESSORIES—Components thatare used with an engine, but are not apart of the engine itself. Units such asmagnetos, carburetors, generators,and fuel pumps are commonlyinstalled engine accessories.

ADJUSTABLE STABILIZER—A stabilizer that can be adjusted inflight to trim the airplane, thereby

even a trim tab, which providesaerodynamic force when it interactswith a moving stream of air.

AIRMANSHIP SKILLS—The skillsof coordination, timing, control touch,and speed sense in addition to themotor skills required to fly an aircraft.

AIRMANSHIP—A sound acquaintance with theprinciples of flight, the ability tooperate an airplane with competenceand precision both on the ground andin the air, and the exercise of soundjudgment that results in optimaloperational safety and efficiency.

AIRPLANE FLIGHT MANUAL(AFM)—A document developed bythe airplane manufacturer andapproved by the Federal AviationAdministration (FAA). It is specific toa particular make and model airplaneby serial number and it containsoperating procedures and limitations.

AIRPLANE OWNER/INFORMATION MANUAL—Adocument developed by the airplanemanufacturer containing generalinformation about the make andmodel of an airplane. The airplaneowner’s manual is not FAA-approvedand is not specific to a particular serialnumbered airplane. This manual is notkept current, and therefore cannot besubstituted for the AFM/POH.

AIRPORT/FACILITYDIRECTORY—A publication designed primarily as apilot’s operational manual containingall airports, seaplane bases, andheliports open to the public includingcommunications data, navigationalfacilities, and certain special noticesand procedures. This publication isissued in seven volumes according togeographical area.

allowing the airplane to fly hands-offat any given airspeed.

ADVERSE YAW—A condition offlight in which the nose of an airplanetends to yaw toward the outside of theturn. This is caused by the higherinduced drag on the outside wing,which is also producing more lift.Induced drag is a by-product of the liftassociated with the outside wing.

AERODYNAMIC CEILING—The point (altitude) at which, as theindicated airspeed decreases with alti-tude, it progressively merges with thelow speed buffet boundary where pre-stall buffet occurs for the airplane at aload factor of 1.0 G.

AERODYNAMICS—The science ofthe action of air on an object, and withthe motion of air on other gases.Aerodynamics deals with theproduction of lift by the aircraft, therelative wind, and the atmosphere.

AILERONS—Primary flight controlsurfaces mounted on the trailing edgeof an airplane wing, near the tip.Ailerons control roll about the longi-tudinal axis.

AIR START—The act or instance ofstarting an aircraft’s engine while inflight, especially a jet engine afterflameout.

AIRCRAFT LOGBOOKS—Journals containing a record of totaloperating time, repairs, alterations orinspections performed, and allAirworthiness Directive (AD) notescomplied with. A maintenancelogbook should be kept for theairframe, each engine, and eachpropeller.

AIRFOIL—An airfoil is any surface,such as a wing, propeller, rudder, or

G-1

Glossary.qxd 5/7/04 10:46 AM Page G-1

G-2

AIRWORTHINESS—A conditionin which the aircraft conforms to itstype certificated design includingsupplemental type certificates, andfield approved alterations. Theaircraft must also be in a condition forsafe flight as determined by annual,100 hour, preflight and any otherrequired inspections.

AIRWORTHINESSCERTIFICATE—A certificate issued by the FAA to allaircraft that have been proven to meetthe minimum standards set down bythe Code of Federal Regulations.

AIRWORTHINESS DIRECTIVE—A regulatory noticesent out by the FAA to the registeredowner of an aircraft informing theowner of a condition that prevents theaircraft from continuing to meetits conditions for airworthiness.Airworthiness Directives (AD notes)must be complied with within therequired time limit, and the fact ofcompliance, the date of compliance,and the method of compliance must berecorded in the aircraft’s maintenancerecords.

ALPHA MODE OFOPERATION—The operation of aturboprop engine that includes all ofthe flight operations, from takeoff tolanding. Alpha operation is typicallybetween 95 percent to 100 percent ofthe engine operating speed.

ALTERNATE AIR—A devicewhich opens, either automaticallyor manually, to allow induction air-flow to continue should the primaryinduction air opening becomeblocked.

ALTERNATE STATIC SOURCE—A manual port that when openedallows the pitot static instruments tosense static pressure from an alternatelocation should the primary static portbecome blocked.

ALTERNATOR/GENERATOR—Adevice that uses engine power to gen-erate electrical power.

ALTIMETER—A flight instrumentthat indicates altitude by sensingpressure changes.

pitch, which is the up and downmovement of the airplane’s nose.

ATTITUDE— The position of anaircraft as determined by therelationship of its axes and a refer-ence, usually the earth’s horizon.

AUTOKINESIS—This is caused bystaring at a single point of lightagainst a dark background for morethan a few seconds. After a fewmoments, the light appears to moveon its own.

AUTOPILOT—An automatic flightcontrol system which keeps an aircraftin level flight or on a set course.Automatic pilots can be directed bythe pilot, or they may be coupled to aradio navigation signal.

AXES OF AN AIRCRAFT—Threeimaginary lines that pass through anaircraft’s center of gravity. The axescan be considered as imaginary axlesaround which the aircraft turns. Thethree axes pass through the center ofgravity at 90° angles to each other.The axis from nose to tail is thelongitudinal axis, the axis that passesfrom wingtip to wingtip is the lateralaxis, and the axis that passes verticallythrough the center of gravity is thevertical axis.

AXIAL FLOW COMPRESSOR—A type of compressor used in a turbineengine in which the airflow throughthe compressor is essentially linear.An axial-flow compressor is made upof several stages of alternate rotorsand stators. The compressor ratio isdetermined by the decrease in area ofthe succeeding stages.

BACK SIDE OF THE POWERCURVE— Flight regime in whichflight at a higher airspeed requires alower power setting and a lowerairspeed requires a higher powersetting in order to maintain altitude.

BALKED LANDING—A go-around.

BALLAST—Removable or perma-nently installed weight in an aircraft

ALTITUDE (AGL)—The actualheight above ground level (AGL) atwhich the aircraft is flying.

ALTITUDE (MSL)—The actualheight above mean sea level (MSL) atwhich the aircraft is flying.

ALTITUDE CHAMBER—A devicethat simulates high altitude conditionsby reducing the interior pressure. Theoccupants will suffer from the samephysiological conditions as flight athigh altitude in an unpressurizedaircraft.

ALTITUDE ENGINE—A reciprocating aircraft engine havinga rated takeoff power that isproducible from sea level to anestablished higher altitude.

ANGLE OF ATTACK—The acuteangle between the chord line of theairfoil and the direction of the relativewind.

ANGLE OF INCIDENCE—The angle formed by the chord line ofthe wing and a line parallel to thelongitudinal axis of the airplane.

ANNUAL INSPECTION—A complete inspection of an aircraftand engine, required by the Codeof Federal Regulations, to beaccomplished every 12 calendarmonths on all certificated aircraft.Only an A&P technician holding anInspection Authorization can conductan annual inspection.

ANTI-ICING—The prevention ofthe formation of ice on a surface. Icemay be prevented by using heat or bycovering the surface with a chemicalthat prevents water from reaching thesurface. Anti-icing should not be con-fused with deicing, which is theremoval of ice after it has formed onthe surface.

ATTITUDE INDICATOR—An instrument which uses an artificialhorizon and miniature airplane todepict the position of the airplane inrelation to the true horizon. Theattitude indicator senses roll as well as

Glossary.qxd 5/7/04 10:46 AM Page G-2

G-3

used to bring the center of gravity intothe allowable range.

BALLOON—The result of a tooaggressive flare during landingcausing the aircraft to climb.

BASIC EMPTY WEIGHT(GAMA)—Basic empty weightincludes the standard empty weightplus optional and special equipmentthat has been installed.

BEST ANGLE OF CLIMB (VX)—The speed at which the aircraft willproduce the most gain in altitude in agiven distance.

BEST GLIDE—The airspeed inwhich the aircraft glides the furthestfor the least altitude lost when innon-powered flight.

BEST RATE OF CLIMB (VY)—The speed at which the aircraft willproduce the most gain in altitude inthe least amount of time.

BLADE FACE—The flat portion of apropeller blade, resembling thebottom portion of an airfoil.

BLEED AIR—Compressed airtapped from the compressor stages ofa turbine engine by use of ducts andtubing. Bleed air can be used fordeice, anti-ice, cabin pressurization,heating, and cooling systems.

BLEED VALVE—In a turbineengine, a flapper valve, a popoffvalve, or a bleed band designed tobleed off a portion of the compressorair to the atmosphere. Used tomaintain blade angle of attack andprovide stall-free engine accelerationand deceleration.

BOOST PUMP—An electricallydriven fuel pump, usually of thecentrifugal type, located in one of thefuel tanks. It is used to provide fuel tothe engine for starting and providingfuel pressure in the event of failure ofthe engine driven pump. It alsopressurizes the fuel lines to preventvapor lock.

CAMBERED—The camber of anairfoil is the characteristic curve of itsupper and lower surfaces. The uppercamber is more pronounced, while thelower camber is comparatively flat.This causes the velocity of the airflowimmediately above the wing to bemuch higher than that below the wing.

CARBURETOR ICE— Ice thatforms inside the carburetor due to thetemperature drop caused by thevaporization of the fuel. Inductionsystem icing is an operational hazardbecause it can cut off the flow of thefuel/air charge or vary the fuel/airratio.

CARBURETOR—1. Pressure: Ahydromechanical device employing aclosed feed system from the fuelpump to the discharge nozzle. Itmeters fuel through fixed jetsaccording to the mass airflow throughthe throttle body and discharges itunder a positive pressure. Pressurecarburetors are distinctly differentfrom float-type carburetors, as they donot incorporate a vented floatchamber or suction pickup from adischarge nozzle located in the venturitube. 2. Float-type: Consistsessentially of a main air passagethrough which the engine draws itssupply of air, a mechanism to controlthe quantity of fuel discharged inrelation to the flow of air, and a meansof regulating the quantity of fuel/airmixture delivered to the enginecylinders.

CASCADE REVERSER—A thrustreverser normally found on turbofanengines in which a blocker door and aseries of cascade vanes are used toredirect exhaust gases in a forwarddirection.

CENTER OF GRAVITY (CG)—The point at which an airplane wouldbalance if it were possible to suspendit at that point. It is the mass center ofthe airplane, or the theoretical point atwhich the entire weight of the airplaneis assumed to be concentrated. It maybe expressed in inches from the refer-ence datum, or in percent of meanaerodynamic chord (MAC). The loca-tion depends on the distribution ofweight in the airplane.

BUFFETING—The beating of anaerodynamic structure or surface byunsteady flow, gusts, etc.; the irregu-lar shaking or oscillation of a vehiclecomponent owing to turbulent air orseparated flow.

BUS BAR—An electrical powerdistribution point to which severalcircuits may be connected. It is often asolid metal strip having a number ofterminals installed on it.

BUS TIE—A switch that connectstwo or more bus bars. It is usuallyused when one generator fails andpower is lost to its bus. By closing theswitch, the operating generatorpowers both busses.

BYPASS AIR—The part of aturbofan’s induction air that bypassesthe engine core.

BYPASS RATIO—The ratio of themass airflow in pounds per secondthrough the fan section of a turbofanengine to the mass airflow that passesthrough the gas generator portion ofthe engine. Or, the ratio between fanmass airflow (lb/sec.) and core enginemass airflow (lb/sec.).

CABIN PRESSURIZATION—Acondition where pressurized air isforced into the cabin simulatingpressure conditions at a much loweraltitude and increasing the aircraftoccupants comfort.

CALIBRATED AIRSPEED(CAS)—Indicated airspeed correctedfor installation error and instrumenterror. Although manufacturers attemptto keep airspeed errors to a minimum,it is not possible to eliminate all errorsthroughout the airspeed operatingrange. At certain airspeeds and withcertain flap settings, the installationand instrument errors may totalseveral knots. This error is generallygreatest at low airspeeds. In thecruising and higher airspeed ranges,indicated airspeed and calibratedairspeed are approximately the same.Refer to the airspeed calibration chartto correct for possible airspeed errors.

Glossary.qxd 5/7/04 10:46 AM Page G-3

G-4

CENTER-OF-GRAVITYLIMITS—The specified forward andaft points within which the CG mustbe located during flight. These limitsare indicated on pertinent airplanespecifications.

CENTER-OF-GRAVITYRANGE—The distance between theforward and aft CG limits indicated onpertinent airplane specifications.

CENTRIFUGALFLOW COMPRESSOR—An impeller-shaped device that receivesair at its center and slings air outward athigh velocity into a diffuser for increasedpressure. Also referred to as a radial out-flow compressor.

CHORD LINE—An imaginarystraight line drawn through an airfoilfrom the leading edge to the trailingedge.

CIRCUIT BREAKER—A circuit-protecting device that opensthe circuit in case of excess currentflow. A circuit breakers differs from afuse in that it can be reset withouthaving to be replaced.

CLEAR AIR TURBULENCE—Turbulence not associated with anyvisible moisture.

CLIMB GRADIENT—The ratiobetween distance traveled and altitudegained.

COCKPIT RESOURCEMANAGEMENT—Techniquesdesigned to reduce pilot errors andmanage errors that do occur utilizingcockpit human resources. Theassumption is that errors are going tohappen in a complex system witherror-prone humans.

COEFFICIENT OF LIFT—SeeLIFT COEFFICIENT.

COFFIN CORNER—The flightregime where any increase in airspeedwill induce high speed mach buffetand any decrease in airspeed willinduce low speed mach buffet.

CONDITION LEVER—In a turbineengine, a powerplant control that con-trols the flow of fuel to the engine.The condition lever sets the desiredengine r.p.m. within a narrow rangebetween that appropriate for groundand flight operations.

CONFIGURATION—This is ageneral term, which normally refers tothe position of the landing gearand flaps.

CONSTANT SPEEDPROPELLER— A controllable-pitch propeller whose pitch isautomatically varied in flight by agovernor to maintain a constant r.p.m.in spite of varying air loads.

CONTROL TOUCH—The ability tosense the action of the airplane and itsprobable actions in the immediatefuture, with regard to attitude andspeed variations, by sensing andevaluation of varying pressures andresistance of the control surfacestransmitted through the cockpit flightcontrols.

CONTROLLABILITY—A measureof the response of an aircraft relativeto the pilot’s flight control inputs.

CONTROLLABLE PITCHPROPELLER—A propeller in whichthe blade angle can be changed duringflight by a control in the cockpit.

CONVENTIONAL LANDINGGEAR—Landing gear employing athird rear-mounted wheel. Theseairplanes are also sometimes referredto as tailwheel airplanes.

COORDINATED FLIGHT—Application of all appropriate flightand power controls to prevent slippingor skidding in any flight condition.

COORDINATION—The ability touse the hands and feet togethersubconsciously and in the properrelationship to produce desired resultsin the airplane.

CORE AIRFLOW—Air drawn intothe engine for the gas generator.

COMBUSTION CHAMBER— Thesection of the engine into which fuelis injected and burned.

COMMON TRAFFICADVISORY FREQUENCY—Thecommon frequency used by airporttraffic to announce position reports inthe vicinity of the airport.

COMPLEX AIRCRAFT—An aircraft with retractable landinggear, flaps, and a controllable-pitchpropeller, or is turbine powered.

COMPRESSION RATIO—1. In areciprocating engine, the ratio of thevolume of an engine cylinder with thepiston at the bottom center to thevolume with the piston at top center.2. In a turbine engine, the ratio of thepressure of the air at the discharge tothe pressure of air at the inlet.

COMPRESSOR BLEED AIR—See BLEED AIR.

COMPRESSOR BLEEDVALVES—See BLEED VALVE.

COMPRESSOR SECTION— Thesection of a turbine engine thatincreases the pressure and density ofthe air flowing through the engine.

COMPRESSOR STALL—In gasturbine engines, a condition in anaxial-flow compressor in which oneor more stages of rotor blades fail topass air smoothly to the succeedingstages. A stall condition is caused by apressure ratio that is incompatiblewith the engine r.p.m. Compressorstall will be indicated by a rise inexhaust temperature or r.p.m.fluctuation, and if allowed tocontinue, may result in flameout andphysical damage to the engine.

COMPRESSOR SURGE—A severecompressor stall across the entirecompressor that can result in severedamage if not quickly corrected. Thiscondition occurs with a completestoppage of airflow or a reversal ofairflow.

Glossary.qxd 5/7/04 10:46 AM Page G-4

G-5

COWL FLAPS—Devices arrangedaround certain air-cooled enginecowlings which may be opened orclosed to regulate the flow of airaround the engine.

CRAB—A flight condition in whichthe nose of the airplane is pointed intothe wind a sufficient amount to coun-teract a crosswind and maintain adesired track over the ground.

CRAZING—Small fractures inaircraft windshields and windowscaused from being exposed to theultraviolet rays of the sun andtemperature extremes.

CRITICAL ALTITUDE—The maximum altitude under standardatmospheric conditions at which aturbocharged engine can produce itsrated horsepower.

CRITICAL ANGLE OF ATTACK—The angle of attack atwhich a wing stalls regardless ofairspeed, flight attitude, or weight.

CRITICAL ENGINE—The enginewhose failure has the most adverseeffect on directional control.

CROSS CONTROLLED—A condition where aileron deflectionis in the opposite direction of rudderdeflection.

CROSSFEED—A system that allowseither engine on a twin-engineairplane to draw fuel from any fueltank.

CROSSWIND COMPONENT—The wind component, measured inknots, at 90° to the longitudinal axisof the runway.

CURRENT LIMITER—A devicethat limits the generator output to alevel within that rated by thegenerator manufacturer.

DATUM (REFERENCEDATUM)—An imaginary verticalplane or line from which allmeasurements of moment arm aretaken. The datum is established by themanufacturer. Once the datum hasbeen selected, all moment arms and

parasite drag to compensate for theadditional induced drag caused by thedown aileron. This balancing of thedrag forces helps minimize adverseyaw.

DIFFUSION—Reducing the velocityof air causing the pressure to increase.

DIRECTIONAL STABILITY—Stability about the vertical axis of anaircraft, whereby an aircraft tends toreturn, on its own, to flight alignedwith the relative wind when disturbedfrom that equilibrium state. Thevertical tail is the primary contributorto directional stability, causing anairplane in flight to align with therelative wind.

DITCHING—Emergency landing inwater.

DOWNWASH—Air deflected perpendicular to themotion of the airfoil.

DRAG—An aerodynamic force on abody acting parallel and opposite tothe relative wind. The resistance ofthe atmosphere to the relative motionof an aircraft. Drag opposes thrust andlimits the speed of the airplane.

DRAG CURVE—A visual representation of the amountof drag of an aircraft at variousairspeeds.

DRIFT ANGLE—Angle betweenheading and track.

DUCTED-FAN ENGINE—An engine-propeller combination thathas the propeller enclosed in a radialshroud. Enclosing the propellerimproves the efficiency of thepropeller.

DUTCH ROLL—A combination ofrolling and yawing oscillations thatnormally occurs when the dihedraleffects of an aircraft are morepowerful than the directional stability.Usually dynamically stable butobjectionable in an airplane becauseof the oscillatory nature.

the location of CG range are measuredfrom this point.

DECOMPRESSION SICKNESS—A condition where the low pressure athigh altitudes allows bubbles ofnitrogen to form in the blood andjoints causing severe pain. Alsoknown as the bends.

DEICER BOOTS—Inflatable rubberboots attached to the leading edge ofan airfoil. They can be sequentiallyinflated and deflated to break away icethat has formed over their surface.

DEICING—Removing ice after ithas formed.

DELAMINATION—The separationof layers.

DENSITY ALTITUDE—This altitude is pressure altitude cor-rected for variations from standardtemperature. When conditions arestandard, pressure altitude and densityaltitude are the same. If the tempera-ture is above standard, the density alti-tude is higher than pressure altitude. Ifthe temperature is below standard, thedensity altitude is lower than pressurealtitude. This is an important altitudebecause it is directly related to theairplane’s performance.

DESIGNATED PILOTEXAMINER (DPE)—An individualdesignated by the FAA to administerpractical tests to pilot applicants.

DETONATION—The sudden release of heat energyfrom fuel in an aircraft engine causedby the fuel-air mixture reaching itscritical pressure and temperature.Detonation occurs as a violentexplosion rather than a smoothburning process.

DEWPOINT—The temperature atwhich air can hold no more water.

DIFFERENTIAL AILERONS—Control surface rigged such that theaileron moving up moves a greaterdistance than the aileron movingdown. The up aileron produces extra

Glossary.qxd 5/7/04 10:46 AM Page G-5

G-6

DYNAMIC HYDROPLANING—Acondition that exists when landing ona surface with standing water deeperthan the tread depth of the tires. Whenthe brakes are applied, there is apossibility that the brake will lock upand the tire will ride on the surface ofthe water, much like a water ski.When the tires are hydroplaning,directional control and braking actionare virtually impossible. An effectiveanti-skid system can minimize theeffects of hydroplaning.

DYNAMIC STABILITY—The property of an aircraft that causesit, when disturbed from straight-and-level flight, to develop forces ormoments that restore the originalcondition of straight and level.

ELECTRICAL BUS—See BUS BAR.

ELECTROHYDRAULIC—Hydraulic control which is electricallyactuated.

ELEVATOR—The horizontal, movable primarycontrol surface in the tail section, orempennage, of an airplane. Theelevator is hinged to the trailing edgeof the fixed horizontal stabilizer.

EMERGENCY LOCATORTRANSMITTER—A small, self-contained radio transmitter that willautomatically, upon the impact of acrash, transmit an emergency signalon 121.5, 243.0, or 406.0 MHz.

EMPENNAGE—The section of theairplane that consists of the verticalstabilizer, the horizontal stabilizer,and the associated control surfaces.

ENGINE PRESSURE RATIO(EPR)—The ratio of turbinedischarge pressure divided bycompressor inlet pressure that is usedas an indication of the amount ofthrust being developed by a turbineengine.

ENVIRONMENTAL SYSTEMS—In an aircraft, the systems, includingthe supplemental oxygen systems, airconditioning systems, heaters, and

FIXED SHAFT TURBOPROPENGINE—A turboprop enginewhere the gas producer spool isdirectly connected to the output shaft.

FIXED-PITCH PROPELLERS—Propellers with fixed blade angles.Fixed-pitch propellers are designed asclimb propellers, cruise propellers, orstandard propellers.

FLAPS—Hinged portion of thetrailing edge between the ailerons andfuselage. In some aircraft, aileronsand flaps are interconnected toproduce full-span “flaperons.” Ineither case, flaps change the lift anddrag on the wing.

FLAT PITCH—A propeller configuration when theblade chord is aligned with the direc-tion of rotation.

FLICKER VERTIGO—A disorientating condition causedfrom flickering light off the blades ofthe propeller.

FLIGHT DIRECTOR—An auto-matic flight control system in whichthe commands needed to fly the air-plane are electronically computed anddisplayed on a flight instrument. Thecommands are followed by the humanpilot with manual control inputs or, inthe case of an autopilot system, sent toservos that move the flight controls.

FLIGHT IDLE—Engine speed,usually in the 70-80 percent range, forminimum flight thrust.

FLOATING—A condition whenlanding where the airplane does notsettle to the runway due to excessiveairspeed.

FORCE (F)—The energy applied toan object that attempts to cause theobject to change its direction, speed,or motion. In aerodynamics, it isexpressed as F, T (thrust), L (lift), W(weight), or D (drag), usually inpounds.

FORM DRAG—The part of parasitedrag on a body resulting from the

pressurization systems, which make itpossible for an occupant to function athigh altitude.

EQUILIBRIUM—A condition thatexists within a body when the sum ofthe moments of all of the forces actingon the body is equal to zero. Inaerodynamics, equilibrium is when allopposing forces acting on an aircraftare balanced (steady, unacceleratedflight conditions).

EQUIVALENT SHAFTHORSEPOWER (ESHP)—A measurement of the total horse-power of a turboprop engine, includ-ing that provided by jet thrust.

EXHAUST GAS TEMPERATURE(EGT)—The temperature of theexhaust gases as they leave thecylinders of a reciprocating engine orthe turbine section of a turbine engine.

EXHAUST MANIFOLD—The partof the engine that collects exhaustgases leaving the cylinders.

EXHAUST—The rear opening of aturbine engine exhaust duct. Thenozzle acts as an orifice, the size ofwhich determines the density andvelocity of the gases as they emergefrom the engine.

FALSE HORIZON—An opticalillusion where the pilot confuses a rowof lights along a road or other straightline as the horizon.

FALSE START—See HUNG START.

FEATHERING PROPELLER(FEATHERED)—A controllablepitch propeller with a pitch rangesufficient to allow the blades to beturned parallel to the line of flight toreduce drag and prevent furtherdamage to an engine that has beenshut down after a malfunction.

FIXATION—A psychological condition where thepilot fixes attention on a single sourceof information and ignores allother sources.

Glossary.qxd 5/7/04 10:46 AM Page G-6

G-7

integrated effect of the static pressureacting normal to its surface resolvedin the drag direction.

FORWARD SLIP—A slip in whichthe airplane’s direction of motion con-tinues the same as before the slip wasbegun. In a forward slip, the airplane’slongitudinal axis is at an angle to itsflightpath.

FREE POWER TURBINEENGINE—A turboprop enginewhere the gas producer spool is on aseparate shaft from the output shaft.The free power turbine spinsindependently of the gas producer anddrives the output shaft.

FRICTION DRAG—The part ofparasitic drag on a body resultingfrom viscous shearing stresses over itswetted surface.

FRISE-TYPE AILERON—Aileronhaving the nose portion projectingahead of the hinge line. When thetrailing edge of the aileron moves up,the nose projects below the wing’slower surface and produces someparasite drag, decreasing the amountof adverse yaw.

FUEL CONTROL UNIT—The fuel-metering device used on aturbine engine that meters the properquantity of fuel to be fed into theburners of the engine. It integrates theparameters of inlet air temperature,compressor speed, compressordischarge pressure, and exhaust gastemperature with the position of thecockpit power control lever.

FUEL EFFICIENCY—Defined asthe amount of fuel used to produce aspecific thrust or horsepower dividedby the total potential power containedin the same amount of fuel.

FUEL HEATERS—A radiator-likedevice which has fuel passing throughthe core. A heat exchange occurs tokeep the fuel temperature above thefreezing point of water so thatentrained water does not form icecrystals, which could block fuel flow.

FUEL INJECTION—A fuel metering system used on someaircraft reciprocating engines in

GO-AROUND—Terminating a landing approach.

GOVERNING RANGE—The rangeof pitch a propeller governor cancontrol during flight.

GOVERNOR—A control whichlimits the maximum rotational speedof a device.

GROSS WEIGHT—The total weight of a fully loadedaircraft including the fuel, oil, crew,passengers, and cargo.

GROUND ADJUSTABLE TRIMTAB—A metal trim tab on a controlsurface that is not adjustable in flight.Bent in one direction or another whileon the ground to apply trim forces tothe control surface.

GROUND EFFECT—A conditionof improved performance encoun-tered when an airplane is operatingvery close to the ground. When anairplane’s wing is under the influenceof ground effect, there is a reductionin upwash, downwash, and wingtipvortices. As a result of the reducedwingtip vortices, induced drag isreduced.

GROUND IDLE—Gas turbineengine speed usually 60-70 percent ofthe maximum r.p.m. range, used as aminimum thrust setting for groundoperations.

GROUND LOOP—A sharp, uncon-trolled change of direction of anairplane on the ground.

GROUND POWER UNIT (GPU)—A type of small gas turbine whosepurpose is to provide electrical power,and/or air pressure for starting aircraftengines. A ground unit is connected tothe aircraft when needed. Similar toan aircraft-installed auxiliary powerunit.

GROUNDSPEED (GS)—The actualspeed of the airplane over the ground.It is true airspeed adjusted forwind. Groundspeed decreases with aheadwind, and increases witha tailwind.

which a constant flow of fuel is fed toinjection nozzles in the heads of allcylinders just outside of the intakevalve. It differs from sequential fuelinjection in which a timed charge ofhigh-pressure fuel is sprayed directlyinto the combustion chamber of thecylinder.

FUEL LOAD—The expendable partof the load of the airplane. It includesonly usable fuel, not fuel required tofill the lines or that which remainstrapped in the tank sumps.

FUEL TANK SUMP—A samplingport in the lowest part of the fuel tankthat the pilot can utilize to check forcontaminants in the fuel.

FUSELAGE—The section of theairplane that consists of the cabinand/or cockpit, containing seats forthe occupants and the controls for theairplane.

GAS GENERATOR—The basicpower producing portion of a gasturbine engine and excluding suchsections as the inlet duct, thefan section, free power turbines,and tailpipe. Each manufacturerdesignates what is included as the gasgenerator, but generally consists ofthe compressor, diffuser, combustor,and turbine.

GAS TURBINE ENGINE—A formof heat engine in which burning fueladds energy to compressed air andaccelerates the air through theremainder of the engine. Some of theenergy is extracted to turn the aircompressor, and the remainderaccelerates the air to produce thrust.Some of this energy can be convertedinto torque to drive a propeller or asystem of rotors for a helicopter.

GLIDE RATIO—The ratio betweendistance traveled and altitude lostduring non-powered flight.

GLIDEPATH—The path of anaircraft relative to the ground whileapproaching a landing.

GLOBAL POSITION SYSTEM(GPS)—A satellite-based radio posi-tioning, navigation, and time-transfersystem.

Glossary.qxd 5/7/04 10:46 AM Page G-7

G-8

GROUND TRACK—The aircraft’spath over the ground when in flight.

GUST PENETRATION SPEED—The speed that gives the greatestmargin between the high and lowmach speed buffets.

GYROSCOPIC PRECESSION—An inherent quality of rotating bodies,which causes an applied force to bemanifested 90º in the direction ofrotation from the point where theforce is applied.

HAND PROPPING—Starting anengine by rotating the propeller byhand.

HEADING—The direction in whichthe nose of the aircraft is pointingduring flight.

HEADING BUG—A marker on theheading indicator that can be rotatedto a specific heading for referencepurposes, or to command an autopilotto fly that heading.

HEADING INDICATOR—An instrument which senses airplanemovement and displays heading basedon a 360º azimuth, with the final zeroomitted. The heading indicator, alsocalled a directional gyro, is funda-mentally a mechanical instrumentdesigned to facilitate the use of themagnetic compass. The heading indi-cator is not affected by the forces thatmake the magnetic compass difficultto interpret.

HEADWIND COMPONENT—Thecomponent of atmospheric winds thatacts opposite to the aircraft’s flight-path.

HIGH PERFORMANCEAIRCRAFT—An aircraft with anengine of more than 200 horsepower.

HORIZON—The line of sightboundary between the earth and thesky.

HORSEPOWER—The term, originated by inventorJames Watt, means the amount ofwork a horse could do in one second.

engine. Some igniters resemble sparkplugs, while others, called glow plugs,have a coil of resistance wire thatglows red hot when electrical currentflows through the coil.

IMPACT ICE—Ice that forms on thewings and control surfaces or on thecarburetor heat valve, the walls of theair scoop, or the carburetor unitsduring flight. Impact ice collecting onthe metering elements of thecarburetor may upset fuel metering orstop carburetor fuel flow.

INCLINOMETER—An instrumentconsisting of a curved glass tube,housing a glass ball, and damped witha fluid similar to kerosene. It may beused to indicate inclination, as a level,or, as used in the turn indicators, toshow the relationship between gravityand centrifugal force in a turn.

INDICATED AIRSPEED (IAS)—The direct instrument readingobtained from the airspeed indicator,uncorrected for variations in atmos-pheric density, installation error, orinstrument error. Manufacturers usethis airspeed as the basis for determin-ing airplane performance. Takeoff,landing, and stall speeds listed in theAFM or POH are indicated airspeedsand do not normally vary with altitudeor temperature.

INDICATED ALTITUDE—The altitude read directly from thealtimeter (uncorrected) when it is setto the current altimeter setting.

INDUCED DRAG—That part oftotal drag which is created by theproduction of lift. Induced dragincreases with a decrease in airspeed.

INDUCTION MANIFOLD—Thepart of the engine that distributesintake air to the cylinders.

INERTIA—The opposition which abody offers to a change of motion.

INITIAL CLIMB—This stage of theclimb begins when the airplane leavesthe ground, and a pitch attitude has

One horsepower equals 550foot-pounds per second, or 33,000foot-pounds per minute.

HOT START—In gas turbineengines, a start which occurs withnormal engine rotation, but exhausttemperature exceeds prescribedlimits. This is usually caused by anexcessively rich mixture in thecombustor. The fuel to the enginemust be terminated immediately toprevent engine damage.

HUNG START—In gas turbineengines, a condition of normal lightoff but with r.p.m. remaining at somelow value rather than increasing to thenormal idle r.p.m. This is often theresult of insufficient power to theengine from the starter. In the event ofa hung start, the engine should be shutdown.

HYDRAULICS—The branch ofscience that deals with thetransmission of power by incompress-ible fluids under pressure.

HYDROPLANING—A conditionthat exists when landing on a surfacewith standing water deeper than thetread depth of the tires. When thebrakes are applied, there is apossibility that the brake will lock upand the tire will ride on the surface ofthe water, much like a water ski.When the tires are hydroplaning,directional control and braking actionare virtually impossible. An effectiveanti-skid system can minimize theeffects of hydroplaning.

HYPOXIA—A lack of sufficientoxygen reaching the body tissues.

IFR (INSTRUMENT FLIGHTRULES)—Rules that govern theprocedure for conducting flight inweather conditions below VFRweather minimums. The term “IFR”also is used to define weatherconditions and the type of flight planunder which an aircraft is operating.

IGNITER PLUGS—The electricaldevice used to provide the spark forstarting combustion in a turbine

Glossary.qxd 5/7/04 10:46 AM Page G-8

G-9

been established to climb away fromthe takeoff area.

INTEGRAL FUEL TANK—A portion of the aircraft structure,usually a wing, which is sealed off andused as a fuel tank. When a wing isused as an integral fuel tank, it iscalled a “wet wing.”

INTERCOOLER—A device used toreduce the temperature of thecompressed air before it enters thefuel metering device. The resultingcooler air has a higher density, whichpermits the engine to be operated witha higher power setting.

INTERNAL COMBUSTION ENGINES—An engine that producespower as a result of expanding hotgases from the combustion of fuel andair within the engine itself. A steamengine where coal is burned to heat upwater inside the engine is an exampleof an external combustion engine.

INTERSTAGE TURBINETEMPERATURE (ITT)—The tem-perature of the gases between the highpressure and low pressure turbines.

INVERTER—An electrical devicethat changes DC to AC power.

ISA (INTERNATIONALSTANDARD ATMOSPHERE)—Standard atmospheric conditionsconsisting of a temperature of 59°F(15°C), and a barometric pressure of29.92 in. Hg. (1013.2 mb) at sea level.ISA values can be calculated forvarious altitudes using a standardlapse rate of approximately 2°C per1,000 feet.

JET POWERED AIRPLANE—Anaircraft powered by a turbojet orturbofan engine.

KINESTHESIA—The sensing ofmovements by feel.

LATERAL AXIS—An imaginaryline passing through the center ofgravity of an airplane and extendingacross the airplane from wingtipto wingtip.

the coefficient of drag for any givenangle of attack.

LIFT-OFF—The act of becomingairborne as a result of the wingslifting the airplane off the ground, orthe pilot rotating the nose up,increasing the angle of attack to start aclimb.

LIMIT LOAD FACTOR—Amountof stress, or load factor, that an aircraftcan withstand before structuraldamage or failure occurs.

LOAD FACTOR—The ratio of theload supported by the airplane’s wingsto the actual weight of the aircraft andits contents. Also referred to asG-loading.

LONGITUDINAL AXIS—An imaginary line through an aircraftfrom nose to tail, passing through itscenter of gravity. The longitudinalaxis is also called the roll axis of theaircraft. Movement of the aileronsrotates an airplane about itslongitudinal axis.

LONGITUDINAL STABILITY(PITCHING)—Stability about thelateral axis. A desirable characteristicof an airplane whereby it tends toreturn to its trimmed angle of attackafter displacement.

MACH—Speed relative to the speedof sound. Mach 1 is the speed ofsound.

MACH BUFFET—Airflow separation behind ashock-wave pressure barrier causedby airflow over flight surfacesexceeding the speed of sound.

MACH COMPENSATINGDEVICE—A device to alert the pilotof inadvertent excursions beyond itscertified maximum operating speed.

MACH CRITICAL—The MACHspeed at which some portion of theairflow over the wing first equalsMACH 1.0. This is also the speed atwhich a shock wave first appears onthe airplane.

LATERAL STABILITY(ROLLING)—The stability about thelongitudinal axis of an aircraft.Rolling stability or the ability of anairplane to return to level flight due toa disturbance that causes one of thewings to drop.

LEAD-ACID BATTERY—A commonly used secondary cellhaving lead as its negative plate andlead peroxide as its positive plate.Sulfuric acid and water serve as theelectrolyte.

LEADING EDGE DEVICES—High lift devices which are found onthe leading edge of the airfoil. Themost common types are fixed slots,movable slats, and leading edge flaps.

LEADING EDGE—The part of anairfoil that meets the airflow first.

LEADING EDGE FLAP—A portion of the leading edge of anairplane wing that folds downward toincrease the camber, lift, and drag ofthe wing. The leading-edge flaps areextended for takeoffs and landings toincrease the amount of aerodynamiclift that is produced at any givenairspeed.

LICENSED EMPTY WEIGHT—The empty weight that consists of theairframe, engine(s), unusable fuel,and undrainable oil plus standard andoptional equipment as specified in theequipment list. Some manufacturersused this term prior to GAMAstandardization.

LIFT—One of the four main forcesacting on an aircraft. On a fixed-wingaircraft, an upward force created bythe effect of airflow as it passes overand under the wing.

LIFT COEFFICIENT— A coeffi-cient representing the lift of a givenairfoil. Lift coefficient is obtained bydividing the lift by the free-streamdynamic pressure and the representa-tive area under consideration.

LIFT/DRAG RATIO—The efficiency of an airfoil section. Itis the ratio of the coefficient of lift to

Glossary.qxd 5/7/04 10:46 AM Page G-9

G-10

MACH TUCK—A condition that canoccur when operating a swept-wingairplane in the transonic speed range.A shock wave could form in the rootportion of the wing and cause theair behind it to separate. Thisshock-induced separation causes thecenter of pressure to move aft. This,combined with the increasing amountof nose down force at higher speeds tomaintain left flight, causes the nose to“tuck.” If not corrected, the airplanecould enter a steep, sometimesunrecoverable dive.

MAGNETIC COMPASS—A devicefor determining direction measuredfrom magnetic north.

MAIN GEAR—The wheels of anaircraft’s landing gear that supportsthe major part of the aircraft’s weight.

MANEUVERABILITY—Ability ofan aircraft to change directions alonga flightpath and withstand the stressesimposed upon it.

MANEUVERING SPEED (VA) —The maximum speed where full,abrupt control movement can be usedwithout overstressing the airframe.

MANIFOLD PRESSURE (MP)—The absolute pressure of the fuel/airmixture within the intake manifold,usually indicated in inches ofmercury.

MAXIMUM ALLOWABLETAKEOFF POWER—The maxi-mum power an engine is allowed todevelop for a limited period of time;usually about one minute.

MAXIMUM LANDINGWEIGHT—The greatest weight thatan airplane normally is allowed tohave at landing.

MAXIMUM RAMP WEIGHT—The total weight of a loaded aircraft,including all fuel. It is greater than thetakeoff weight due to the fuel that willbe burned during the taxi and runupoperations. Ramp weight may also bereferred to as taxi weight.

allows air to continue flowing over thetop of the wing and delays airflowseparation.

MUSHING—A flight conditioncaused by slow speed where thecontrol surfaces are marginallyeffective.

N1, N2, N3—Spool speed expressed inpercent rpm. N1 on a turboprop is thegas producer speed. N1 on a turbofanor turbojet engine is the fan speed orlow pressure spool speed. N2 is thehigh pressure spool speed on enginewith 2 spools and medium pressurespool on engines with 3 spools withN3 being the high pressure spool.

NACELLE—A streamlined enclosure on an aircraftin which an engine is mounted.On multiengine propeller-drivenairplanes, the nacelle is normallymounted on the leading edge of thewing.

NEGATIVE STATIC STABILITY—The initial tendencyof an aircraft to continue away fromthe original state of equilibrium afterbeing disturbed.

NEGATIVE TORQUE SENSING(NTS)— A system in a turbopropengine that prevents the engine frombeing driven by the propeller. TheNTS increases the blade angle whenthe propellers try to drive the engine.

NEUTRAL STATICSTABILITY—The initial tendencyof an aircraft to remain in a newcondition after its equilibrium hasbeen disturbed.

NICKEL-CADMIUM BATTERY(NICAD)— A battery made up ofalkaline secondary cells. The positiveplates are nickel hydroxide, thenegative plates are cadmiumhydroxide, and potassium hydroxideis used as the electrolyte.

NORMAL CATEGORY—An airplane that has a seatingconfiguration, excluding pilot seats,

MAXIMUM TAKEOFFWEIGHT—The maximum allowableweight for takeoff.

MAXIMUM WEIGHT—The maximum authorized weight ofthe aircraft and all of its equipment asspecified in the Type Certificate DataSheets (TCDS) for the aircraft.

MAXIMUM ZERO FUELWEIGHT (GAMA)—The maximumweight, exclusive of usable fuel.

MINIMUM CONTROLLABLEAIRSPEED—An airspeed at whichany further increase in angle of attack,increase in load factor, or reduction inpower, would result in an immediatestall.

MINIMUM DRAG SPEED(L/DMAX)—The point on the totaldrag curve where the lift-to-drag ratiois the greatest. At this speed, total dragis minimized.

MIXTURE—The ratio of fuel to airentering the engine’s cylinders.

MMO—Maximum operating speedexpressed in terms of a decimal ofmach speed.

MOMENT ARM—The distancefrom a datum to the applied force.

MOMENT INDEX (OR INDEX)—A moment divided by a constant suchas 100, 1,000, or 10,000. The purposeof using a moment index is to simplifyweight and balance computations ofairplanes where heavy items and longarms result in large, unmanageablenumbers.

MOMENT—The product of theweight of an item multiplied by itsarm. Moments are expressed inpound-inches (lb-in). Total moment isthe weight of the airplane multipliedby the distance between the datum andthe CG.

MOVABLE SLAT—A movableauxiliary airfoil on the leading edge ofa wing. It is closed in normal flight butextends at high angles of attack. This

Glossary.qxd 5/7/04 10:46 AM Page G-10

G-11

of nine or less, a maximumcertificated takeoff weight of 12,500pounds or less, and intended fornonacrobatic operation.

NORMALIZING(TURBONORMALIZING)—A turbocharger that maintains sealevel pressure in the induction mani-fold at altitude.

OCTANE—The rating system ofaviation gasoline with regard to itsantidetonating qualities.

OVERBOOST—A condition inwhich a reciprocating engine hasexceeded the maximum manifoldpressure allowed by the manufacturer.Can cause damage to enginecomponents.

OVERSPEED—A condition inwhich an engine has produced morer.p.m. than the manufacturerrecommends, or a condition in whichthe actual engine speed is higher thanthe desired engine speed as set on thepropeller control.

OVERTEMP—A condition in whicha device has reached a temperatureabove that approved by themanufacturer or any exhausttemperature that exceeds themaximum allowable for a given oper-ating condition or time limit. Cancause internal damage to an engine.

OVERTORQUE—A condition inwhich an engine has produced moretorque (power) than the manufacturerrecommends, or a condition in aturboprop or turboshaft engine wherethe engine power has exceeded themaximum allowable for a givenoperating condition or time limit. Cancause internal damage to an engine.

PARASITE DRAG—That part oftotal drag created by the design orshape of airplane parts. Parasite dragincreases with an increase in airspeed.

PAYLOAD (GAMA)—The weightof occupants, cargo, and baggage.

P-FACTOR—A tendency for anaircraft to yaw to the left due to the

for scheduling fuel flow to thecombustion chambers of a turbineengine.

POWER—Implies work rate or unitsof work per unit of time, and as such,it is a function of the speed at whichthe force is developed. The term“power required” is generallyassociated with reciprocating engines.

POWERPLANT—A complete engine and propellercombination with accessories.

PRACTICAL SLIP LIMIT—Themaximum slip an aircraft is capable ofperforming due to rudder travel limits.

PRECESSION—The tilting orturning of a gyro in response todeflective forces causing slow driftingand erroneous indications ingyroscopic instruments.

PREIGNITION—Ignition occurringin the cylinder before the time ofnormal ignition. Preignition is oftencaused by a local hot spot in thecombustion chamber igniting thefuel/air mixture.

PRESSURE ALTITUDE—The altitude indicated when thealtimeter setting window (barometricscale) is adjusted to 29.92. This is thealtitude above the standard datumplane, which is a theoretical planewhere air pressure (corrected to 15ºC)equals 29.92 in. Hg. Pressure altitudeis used to compute density altitude,true altitude, true airspeed, and otherperformance data.

PROFILE DRAG—The total of theskin friction drag and form drag for atwo-dimensional airfoil section.

PROPELLER BLADE ANGLE—The angle between the propeller chordand the propeller plane of rotation.

PROPELLER LEVER—

The control on a free power turbineturboprop that controls propellerspeed and the selection for propellerfeathering.

PROPELLER SLIPSTREAM—The volume of air accelerated behinda propeller producing thrust.

descending propeller blade on theright producing more thrust than theascending blade on the left. Thisoccurs when the aircraft’slongitudinal axis is in a climbingattitude in relation to the relativewind. The P-factor would be to theright if the aircraft had a counterclock-wise rotating propeller.

PILOT’S OPERATINGHANDBOOK (POH)—A documentdeveloped by the airplanemanufacturer and contains the FAA-approved Airplane Flight Manual(AFM) information.

PISTON ENGINE—A reciprocatingengine.

PITCH—The rotation of an airplaneabout its lateral axis, or on a propeller,the blade angle as measured fromplane of rotation.

PIVOTAL ALTITUDE—A specificaltitude at which, when an airplaneturns at a given groundspeed, a pro-jecting of the sighting reference lineto a selected point on the ground willappear to pivot on that point.

PNEUMATIC SYSTEMS—The power system in an aircraft usedfor operating such items as landinggear, brakes, and wing flaps withcompressed air as the operating fluid.

PORPOISING—Oscillating around the lateral axis ofthe aircraft during landing.

POSITION LIGHTS—Lights on anaircraft consisting of a red light on theleft wing, a green light on the rightwing, and a white light on the tail.CFRs require that these lights bedisplayed in flight from sunset tosunrise.

POSITIVE STATIC STABILITY—The initial tendency to return to a stateof equilibrium when disturbed fromthat state.

POWER DISTRIBUTION BUS—See BUS BAR.

POWER LEVER—The cockpitlever connected to the fuel control unit

Glossary.qxd 5/7/04 10:46 AM Page G-11

G-12

PROPELLERSYNCHRONIZATION—A condition in which all ofthe propellers have their pitchautomatically adjusted to maintain aconstant r.p.m. among all of theengines of a multiengine aircraft.

PROPELLER—A device forpropelling an aircraft that, whenrotated, produces by its action onthe air, a thrust approximatelyperpendicular to its plane of rotation.It includes the control componentsnormally supplied by itsmanufacturer.

RAMP WEIGHT—The total weightof the aircraft while on the ramp. Itdiffers from takeoff weight by theweight of the fuel that will beconsumed in taxiing to the point oftakeoff.

RATE OF TURN—The rate indegrees/second of a turn.

RECIPROCATING ENGINE—Anengine that converts the heat energyfrom burning fuel into thereciprocating movement of the pis-tons. This movement is converted intoa rotary motion by the connecting rodsand crankshaft.

REDUCTION GEAR—The geararrangement in an aircraft engine thatallows the engine to turn at a fasterspeed than the propeller.

REGION OF REVERSECOMMAND—Flight regime inwhich flight at a higher airspeedrequires a lower power setting and alower airspeed requires a higherpower setting in order to maintainaltitude.

REGISTRATIONCERTIFICATE—A State and Fed-eral certificate that documentsaircraft ownership.

RELATIVE WIND—The directionof the airflow with respect to the wing.If a wing moves forward horizontally,the relative wind moves backwardhorizontally. Relative wind is parallelto and opposite the flightpath ofthe airplane.

alignment guidance during takeoffand landings. The centerline consistsof a line of uniformly spaced stripesand gaps.

RUNWAY EDGE LIGHTS—Runway edge lights are used tooutline the edges of runways duringperiods of darkness or restrictedvisibility conditions. These lightsystems are classified according to theintensity or brightness they arecapable of producing: they are theHigh Intensity Runway Lights(HIRL), Medium Intensity RunwayLights (MIRL), and the Low IntensityRunway Lights (LIRL). The HIRLand MIRL systems have variableintensity controls, whereas the LIRLsnormally have one intensity setting.

RUNWAY END IDENTIFIERLIGHTS (REIL)—One componentof the runway lighting system. Theselights are installed at many airfieldsto provide rapid and positiveidentification of the approach end of aparticular runway.

RUNWAY INCURSION—Any occurrence at an airportinvolving an aircraft, vehicle, person,or object on the ground that creates acollision hazard or results in loss ofseparation with an aircraft taking off,intending to takeoff, landing, orintending to land.

RUNWAY THRESHOLDMARKINGS—Runway thresholdmarkings come in two configura-tions. They either consist of eightlongitudinal stripes of uniformdimensions disposed symmetricallyabout the runway centerline, or thenumber of stripes is related to therunway width. A threshold markinghelps identify the beginning of therunway that is available for landing.In some instances, the landingthreshold may be displaced.

SAFETY (SQUAT) SWITCH—Anelectrical switch mounted on one ofthe landing gear struts. It is used tosense when the weight of the aircraftis on the wheels.

SCAN—A procedure used by thepilot to visually identify all resourcesof information in flight.

REVERSE THRUST—A conditionwhere jet thrust is directed forwardduring landing to increase the rate ofdeceleration.

REVERSING PROPELLER—A propeller system with a pitchchange mechanism that includes fullreversing capability. When the pilotmoves the throttle controls to reverse,the blade angle changes to a pitchangle and produces a reverse thrust,which slows the airplane down duringa landing.

ROLL—The motion of the aircraftabout the longitudinal axis. It iscontrolled by the ailerons.

ROUNDOUT (FLARE)—A pitch-up during landing approach toreduce rate of descent and forwardspeed prior to touchdown.

RUDDER—The movable primarycontrol surface mounted on thetrailing edge of the vertical fin of anairplane. Movement of the rudderrotates the airplane about its verticalaxis.

RUDDERVATOR—A pair of controlsurfaces on the tail of an aircraftarranged in the form of a V. Thesesurfaces, when moved together by thecontrol wheel, serve as elevators, andwhen moved differentially by therudder pedals, serve as a rudder.

RUNWAY CENTERLINELIGHTS—Runway centerline lightsare installed on some precisionapproach runways to facilitate landingunder adverse visibility conditions.They are located along the runwaycenterline and are spaced at 50-footintervals. When viewed from thelanding threshold, the runwaycenterline lights are white until thelast 3,000 feet of the runway. Thewhite lights begin to alternate with redfor the next 2,000 feet, and for the last1,000 feet of the runway, all centerlinelights are red.

RUNWAY CENTERLINEMARKINGS—The runway centerline identifies thecenter of the runway and provides

Glossary.qxd 5/7/04 10:46 AM Page G-12

G-13

SEA LEVEL—A reference heightused to determine standardatmospheric conditions and altitudemeasurements.

SEGMENTED CIRCLE—A visualground based structure to providetraffic pattern information.

SERVICE CEILING—The maximum density altitude wherethe best rate-of-climb airspeed willproduce a 100 feet-per-minute climbat maximum weight while in a cleanconfiguration with maximum continu-ous power.

SERVO TAB—An auxiliary controlmounted on a primary control surface,which automatically moves in thedirection opposite the primary controlto provide an aerodynamic assist inthe movement of the control.

SHAFT HORSE POWER (SHP)—Turboshaft engines are rated in shafthorsepower and calculated by use ofa dynamometer device. Shafthorsepower is exhaust thrustconverted to a rotating shaft.

SHOCK WAVES—A compressionwave formed when a body movesthrough the air at a speed greater thanthe speed of sound.

SIDESLIP—A slip in which theairplane’s longitudinal axis remainsparallel to the original flightpath, but theairplane no longer flies straight ahead.Instead, the horizontal component ofwing lift forces the airplane to movesideways toward the low wing.

SINGLE ENGINE ABSOLUTECEILING—The altitude that a twin-engine airplane can no longer climbwith one engine inoperative.

SINGLE ENGINE SERVICECEILING—The altitude that a twin-engine airplane can no longer climb ata rate greater then 50 f.p.m. with oneengine inoperative.

SKID—A condition where the tail ofthe airplane follows a path outside thepath of the nose during a turn.

SPLIT SHAFTTURBINE ENGINE—See FREEPOWER TURBINE ENGINE.

SPOILERS—High-drag devices thatcan be raised into the air flowing overan airfoil, reducing lift and increasingdrag. Spoilers are used for roll controlon some aircraft. Deploying spoilerson both wings at the same time allowsthe aircraft to descend without gain-ing speed. Spoilers are also used toshorten the ground roll after landing.

SPOOL—A shaft in a turbine enginewhich drives one or morecompressors with the power derivedfrom one or more turbines.

STABILATOR—A single-piece hor-izontal tail surface on an airplane thatpivots around a central hinge point. Astabilator serves the purposes of boththe horizontal stabilizer andthe elevator.

STABILITY—The inherent qualityof an airplane to correct for conditionsthat may disturb its equilibrium, andto return or to continue on the originalflightpath. It is primarily an airplanedesign characteristic.

STABILIZED APPROACH—Alanding approach in which the pilotestablishes and maintains a constantangle glidepath towards a predeter-mined point on the landing runway. Itis based on the pilot’s judgment ofcertain visual cues, and depends onthe maintenance of a constant finaldescent airspeed and configuration.

STALL—A rapid decrease in liftcaused by the separation of airflowfrom the wing’s surface brought on byexceeding the critical angle of attack.A stall can occur at any pitch attitudeor airspeed.

STALL STRIPS—A spoiler attachedto the inboard leading edge of somewings to cause the center section ofthe wing to stall before the tips. Thisassures lateral control throughout thestall.

SLIP—An intentional maneuver todecrease airspeed or increase rate ofdescent, and to compensate for acrosswind on landing. A slip can alsobe unintentional when the pilot failsto maintain the aircraft in coordinatedflight.

SPECIFIC FUELCONSUMPTION—Number of pounds of fuel consumedin 1 hour to produce 1 HP.

SPEED—The distance traveled in agiven time.

SPEED BRAKES—A controlsystem that extends from the airplanestructure into the airstream toproduce drag and slow the airplane.

SPEED INSTABILITY—A condition in the region of reversecommand where a disturbance thatcauses the airspeed to decrease causestotal drag to increase, which in turn,causes the airspeed to decreasefurther.

SPEED SENSE—The ability tosense instantly and react to anyreasonable variation of airspeed.

SPIN—An aggravated stall thatresults in what is termed an “autorota-tion” wherein the airplane follows adownward corkscrew path. As the air-plane rotates around the vertical axis,the rising wing is less stalled than thedescending wing creating a rolling,yawing, and pitching motion.

SPIRAL INSTABILITY—

A condition that exists when the staticdirectional stability of the airplane isvery strong as compared to the effectof its dihedral in maintaining lateralequilibrium.

SPIRALING SLIPSTREAM—Theslipstream of a propeller-drivenairplane rotates around the airplane.This slipstream strikes the left side ofthe vertical fin, causing the airplane toyaw slightly. Vertical stabilizer offsetis sometimes used by aircraft design-ers to counteract this tendency.

Glossary.qxd 5/7/04 10:46 AM Page G-13

G-14

STANDARD ATMOSPHERE—At sea level, the standard atmosphereconsists of a barometric pressure of29.92 inches of mercury (in. Hg.) or1013.2 millibars, and a temperature of15°C (59°F). Pressure and tempera-ture normally decrease as altitudeincreases. The standard lapse rate inthe lower atmosphere for each 1,000feet of altitude is approximately 1 in.Hg. and 2°C (3.5°F). For example, thestandard pressure and temperature at3,000 feet mean sea level (MSL) is26.92 in. Hg. (29.92 - 3) and 9°C(15°C - 6°C).

STANDARD DAY—See STANDARD ATMOSPHERE.

STANDARD EMPTY WEIGHT(GAMA)—This weight consists ofthe airframe, engines, and all items ofoperating equipment that have fixedlocations and are permanentlyinstalled in the airplane; includingfixed ballast, hydraulic fluid, unusablefuel, and full engine oil.

STANDARD WEIGHTS—Thesehave been established for numerousitems involved in weight and balancecomputations. These weights shouldnot be used if actual weights areavailable.

STANDARD-RATE TURN—A turnat the rate of 3º per second whichenables the airplane to complete a360º turn in 2 minutes.

STARTER/GENERATOR—A combined unit used on turbineengines. The device acts as a starterfor rotating the engine, and afterrunning, internal circuits are shifted toconvert the device into a generator.

STATIC STABILITY—The initialtendency an aircraft displays whendisturbed from a state of equilibrium.

STATION—A location in theairplane that is identified by a numberdesignating its distance in inches fromthe datum. The datum is, therefore,identified as station zero. An itemlocated at station +50 would have anarm of 50 inches.

TAXIWAY LIGHTS—Omnidirectional lights that outline theedges of the taxiway and are blue incolor.

TAXIWAY TURNOFF LIGHTS—Flush lights which emit a steady greencolor.

TETRAHEDRON—A large, triangular-shaped, kite-likeobject installed near the runway.Tetrahedrons are mounted on a pivotand are free to swing with the wind toshow the pilot the direction of thewind as an aid in takeoffs andlandings.

THROTTLE—The valve in acarburetor or fuel control unit thatdetermines the amount of fuel-airmixture that is fed to the engine.

THRUST LINE—An imaginary linepassing through the center of thepropeller hub, perpendicular to theplane of the propeller rotation.

THRUST REVERSERS—Deviceswhich redirect the flow of jet exhaustto reverse the direction of thrust.

THRUST—The force which impartsa change in the velocity of a mass.This force is measured in pounds buthas no element of time or rate. Theterm, thrust required, is generallyassociated with jet engines. A forwardforce which propels the airplanethrough the air.

TIMING—The application ofmuscular coordination at the properinstant to make flight, and allmaneuvers incident thereto, a constantsmooth process.

TIRE CORD—Woven metal wirelaminated into the tire to provide extrastrength. A tire showing any cordmust be replaced prior to any furtherflight.

TORQUE METER—An indicatorused on some large reciprocatingengines or on turboprop engines toindicate the amount of torque theengine is producing.

STICK PULLER—A device thatapplies aft pressure on the controlcolumn when the airplane is approach-ing the maximum operating speed.

STICK PUSHER—A device thatapplies an abrupt and large forwardforce on the control column when theairplane is nearing an angle of attackwhere a stall could occur.

STICK SHAKER—An artificialstall warning device that vibrates thecontrol column.

STRESS RISERS—A scratch, groove, rivet hole, forgingdefect or other structural discontinuitythat causes a concentration of stress.

SUBSONIC—Speed below the speedof sound.

SUPERCHARGER—An engine- orexhaust-driven air compressor used toprovide additional pressure to theinduction air so the engine canproduce additional power.

SUPERSONIC—Speed above thespeed of sound.

SUPPLEMENTAL TYPECERTIFICATE (STC)—A certificate authorizing an alterationto an airframe, engine, or componentthat has been granted an ApprovedType Certificate.

SWEPT WING—A wing planformin which the tips of the wing arefarther back than the wing root.

TAILWHEEL AIRCRAFT—SEE CONVENTIONAL LANDINGGEAR.

TAKEOFF ROLL(GROUND ROLL)—The totaldistance required for an aircraft tobecome airborne.

TARGET REVERSER—A thrustreverser in a jet engine in whichclamshell doors swivel from thestowed position at the engine tailpipeto block all of the outflow and redirectsome component of the thrustforward.

Glossary.qxd 5/7/04 10:46 AM Page G-14

G-15

TORQUE SENSOR—See TORQUE METER.

TORQUE—1. A resistance to turningor twisting. 2. Forces that produce atwisting or rotating motion. 3. In anairplane, the tendency of the aircraftto turn (roll) in the opposite directionof rotation of the engine and propeller.

TOTAL DRAG—The sum of theparasite and induced drag.

TOUCHDOWN ZONE LIGHTS—Two rows of transverse light barsdisposed symmetrically about therunway centerline in the runwaytouchdown zone.

TRACK—The actual path made overthe ground in flight.

TRAILING EDGE—The portion ofthe airfoil where the airflow over theupper surface rejoins the lowersurface airflow.

TRANSITION LINER—The portion of the combustor thatdirects the gases into the turbineplenum.

TRANSONIC—At the speed ofsound.

TRANSPONDER—The airborneportion of the secondary surveillanceradar system. The transponder emits areply when queried by a radar facility.

TRICYCLE GEAR—Landing gearemploying a third wheel located onthe nose of the aircraft.

TRIM TAB—A small auxiliaryhinged portion of a movable controlsurface that can be adjusted duringflight to a position resulting in abalance of control forces.

TRIPLE SPOOL ENGINE—Usually a turbofan engine designwhere the fan is the N1 compressor,followed by the N2 intermediatecompressor, and the N3 high pressurecompressor, all of which rotate onseparate shafts at different speeds.

TURBINE SECTION—The sectionof the engine that converts highpressure high temperature gas intorotational energy.

TURBOCHARGER—An air compressor driven by exhaustgases, which increases the pressure ofthe air going into the engine throughthe carburetor or fuel injectionsystem.

TURBOFAN ENGINE—A turbojetengine in which additional propulsivethrust is gained by extending a portionof the compressor or turbine bladesoutside the inner engine case. Theextended blades propel bypass airalong the engine axis but between theinner and outer casing. The air is notcombusted but does provide addi-tional thrust.

TURBOJET ENGINE—A jetengine incorporating a turbine-drivenair compressor to take in and com-press air for the combustion of fuel,the gases of combustion being usedboth to rotate the turbine and create athrust producing jet.

TURBOPROP ENGINE—A turbineengine that drives a propeller througha reduction gearing arrangement.Most of the energy in the exhaustgases is converted into torque, ratherthan its acceleration being used topropel the aircraft.

TURBULENCE—An occurrence inwhich a flow of fluid is unsteady.

TURN COORDINATOR—A rategyro that senses both roll and yaw dueto the gimbal being canted. Haslargely replaced the turn-and-slipindicator in modern aircraft.

TURN-AND-SLIP INDICATOR—A flight instrument consisting of a rategyro to indicate the rate of yaw and acurved glass inclinometer to indicatethe relationship between gravity andcentrifugal force. The turn-and-slipindicator indicates the relationshipbetween angle of bank and rate ofyaw. Also called a turn-and-bankindicator.

TROPOPAUSE—The boundarylayer between the troposphere and themesosphere which acts as a lid toconfine most of the water vapor, andthe associated weather, to thetroposphere.

TROPOSPHERE—The layer of theatmosphere extending from thesurface to a height of 20,000 to 60,000feet depending on latitude.

TRUE AIRSPEED (TAS)—Calibrated airspeed corrected for alti-tude and nonstandard temperature.Because air density decreases with anincrease in altitude, an airplane has tobe flown faster at higher altitudes tocause the same pressure differencebetween pitot impact pressure andstatic pressure. Therefore, for a givencalibrated airspeed, true airspeedincreases as altitude increases; or for agiven true airspeed, calibrated air-speed decreases as altitude increases.

TRUE ALTITUDE—The verticaldistance of the airplane above sealevel—the actual altitude. It is oftenexpressed as feet above mean sealevel (MSL). Airport, terrain, andobstacle elevations on aeronauticalcharts are true altitudes.

T-TAIL—An aircraft with thehorizontal stabilizer mounted on thetop of the vertical stabilizer, forminga T.

TURBINE BLADES—The portionof the turbine assembly that absorbsthe energy of the expanding gases andconverts it into rotational energy.

TURBINE OUTLETTEMPERATURE (TOT)—The temperature of the gases as theyexit the turbine section.

TURBINE PLENUM—The portionof the combustor where the gases arecollected to be evenly distributed tothe turbine blades.

TURBINE ROTORS—The portionof the turbine assembly that mounts tothe shaft and holds the turbine bladesin place.

Glossary.qxd 5/7/04 10:46 AM Page G-15

G-16

TURNING ERROR—One of theerrors inherent in a magnetic compasscaused by the dip compensatingweight. It shows up only on turns to orfrom northerly headings in theNorthern Hemisphere and southerlyheadings in the Southern Hemisphere.Turning error causes the compass tolead turns to the north or south and lagturns away from the north or south.

ULTIMATE LOAD FACTOR—In stress analysis, the load that causesphysical breakdown in an aircraft oraircraft component during a strengthtest, or the load that according tocomputations, should cause such abreakdown.

UNFEATHERINGACCUMULATOR—Tanks that holdoil under pressure which can be usedto unfeather a propeller.

UNICOM—A nongovernment air/ground radiocommunication station which mayprovide airport information at publicuse airports where there is no tower orFSS.

UNUSABLE FUEL—Fuel thatcannot be consumed by the engine.This fuel is considered part of theempty weight of the aircraft.

USEFUL LOAD—The weight of thepilot, copilot, passengers, baggage,usable fuel, and drainable oil. It is thebasic empty weight subtracted fromthe maximum allowable gross weight.This term applies to general aviationaircraft only.

UTILITY CATEGORY—An airplane that has a seatingconfiguration, excluding pilot seats,of nine or less, a maximumcertificated takeoff weight of 12,500pounds or less, and intended forlimited acrobatic operation.

V-BARS—The flight directordisplays on the attitude indicator thatprovide control guidance to the pilot.

V-SPEEDS—Designated speeds for aspecific flight condition.

VFE—The maximum speed with theflaps extended. The upper limit of thewhite arc.

VFO—The maximum speed that theflaps can be extended or retracted.

VFR TERMINAL AREACHARTS (1:250,000)—Depict Class B airspace whichprovides for the control orsegregation of all the aircraft withinthe Class B airspace. The chart depictstopographic information andaeronautical information whichincludes visual and radio aidsto navigation, airports, controlledairspace, restricted areas, obstruc-tions, and related data.

V-G DIAGRAM—A chart thatrelates velocity to load factor. It isvalid only for a specific weight,configuration, and altitude and showsthe maximum amount of positive ornegative lift the airplane is capable ofgenerating at a given speed. Alsoshows the safe load factor limits andthe load factor that the aircraft cansustain at various speeds.

VISUAL APPROACH SLOPEINDICATOR (VASI)—The most common visual glidepathsystem in use. The VASI providesobstruction clearance within 10° ofthe extended runway centerline, andto 4 nautical miles (NM) from therunway threshold.

VISUAL FLIGHTRULES (VFR)—Code of Federal Regulations that gov-ern the procedures for conductingflight under visual conditions.

VLE—Landing gear extended speed.The maximum speed at which anairplane can be safely flown with thelanding gear extended.

VLOF—Lift-off speed. The speed atwhich the aircraft departs the runwayduring takeoff.

VLO—Landing gear operating speed.The maximum speed for extending orretracting the landing gear if using anairplane equipped with retractablelanding gear.

VAPOR LOCK—A condition inwhich air enters the fuel system and itmay be difficult, or impossible, torestart the engine. Vapor lock mayoccur as a result of running a fuel tankcompletely dry, allowing air to enterthe fuel system. On fuel-injectedengines, the fuel may become so hot itvaporizes in the fuel line, not allowingfuel to reach the cylinders.

VA—The design maneuvering speed.This is the “rough air” speed and themaximum speed for abruptmaneuvers. If during flight, rough airor severe turbulence is encountered,reduce the airspeed to maneuveringspeed or less to minimize stress on theairplane structure. It is important toconsider weight when referencing thisspeed. For example, VA may be 100knots when an airplane is heavilyloaded, but only 90 knots when theload is light.

VECTOR—A force vector is agraphic representation of a force andshows both the magnitude anddirection of the force.

VELOCITY—The speed or rate ofmovement in a certain direction.

VERTICAL AXIS—An imaginaryline passing vertically through thecenter of gravity of an aircraft. Thevertical axis is called the z-axis or theyaw axis.

VERTICAL CARD COMPASS—A magnetic compass that consists ofan azimuth on a vertical card,resembling a heading indicator with afixed miniature airplane to accuratelypresent the heading of the aircraft.The design uses eddy currentdamping to minimize lead and lagduring turns.

VERTICALSPEED INDICATOR (VSI)—An instrument that uses static pressureto display a rate of climb or descent infeet per minute. The VSI can alsosometimes be called a verticalvelocity indicator (VVI).

VERTICAL STABILITY—Stabilityabout an aircraft’s vertical axis. Alsocalled yawing or directional stability.

Glossary.qxd 5/7/04 10:46 AM Page G-16

G-17

VMC—Minimum control airspeed.This is the minimum flight speed atwhich a twin-engine airplane can besatisfactorily controlled when anengine suddenly becomes inoperativeand the remaining engine is at takeoffpower.

VMD—Minimum drag speed.

VMO—Maximum operating speedexpressed in knots.

VNE—Never-exceed speed. Operatingabove this speed is prohibited since itmay result in damage or structuralfailure. The red line on the airspeedindicator.

VNO—Maximum structural cruisingspeed. Do not exceed this speedexcept in smooth air. The upper limitof the green arc.

VP—Minimum dynamic hydroplan-ing speed. The minimum speedrequired to start dynamichydroplaning.

VR—Rotation speed. The speed thatthe pilot begins rotating the aircraftprior to lift-off.

VS0—Stalling speed or the minimumsteady flight speed in the landing con-figuration. In small airplanes, this isthe power-off stall speed at the maxi-mum landing weight in the landingconfiguration (gear and flaps down).The lower limit of the white arc.

VS1—Stalling speed or the minimumsteady flight speed obtained in aspecified configuration. For mostairplanes, this is the power-off stallspeed at the maximum takeoff weightin the clean configuration (gear up, ifretractable, and flaps up). The lowerlimit of the green arc.

VSSE—Safe, intentional one-engineinoperative speed. The minimumspeed to intentionally render thecritical engine inoperative.

V-TAIL—A design which utilizestwo slanted tail surfaces to perform

equal to the mass of the body timesthe local value of gravitationalacceleration. One of the four mainforces acting on an aircraft.Equivalent to the actual weight of theaircraft. It acts downward through theaircraft’s center of gravity toward thecenter of the Earth. Weight opposeslift.

WEIGHT AND BALANCE—Theaircraft is said to be in weight andbalance when the gross weight of theaircraft is under the max gross weight,and the center of gravity is withinlimits and will remain in limits for theduration of the flight.

WHEELBARROWING—A condition caused when forwardyoke or stick pressure during takeoffor landing causes the aircraft to rideon the nosewheel alone.

WIND CORRECTION ANGLE—Correction applied to the course toestablish a heading so that track willcoincide with course.

WINDDIRECTION INDICATORS—Indicators that include a wind sock,wind tee, or tetrahedron. Visualreference will determine winddirection and runway in use.

WIND SHEAR—A sudden, drasticshift in windspeed, direction, or boththat may occur in the horizontal orvertical plane.

WINDMILLING—When the airmoving through a propeller createsthe rotational energy.

WINDSOCK—A truncated clothcone open at both ends and mountedon a freewheeling pivot that indicatesthe direction from which the wind isblowing.

WING—Airfoil attached to each sideof the fuselage and are the mainlifting surfaces that support theairplane in flight.

the same functions as the surfaces of aconventional elevator and rudderconfiguration. The fixed surfaces actas both horizontal and verticalstabilizers.

VX—Best angle-of-climb speed. Theairspeed at which an airplane gains thegreatest amount of altitude in a givendistance. It is used during a short-fieldtakeoff to clear an obstacle.

VXSE—Best angle of climb speed withone engine inoperative. The airspeedat which an airplane gains the greatestamount of altitude in a given distancein a light, twin-engine airplanefollowing an engine failure.

VY—Best rate-of-climb speed. Thisairspeed provides the most altitudegain in a given period of time.

VYSE—Best rate-of-climb speed withone engine inoperative. This airspeedprovides the most altitude gain in agiven period of time in a light, twin-engine airplane following an enginefailure.

WAKE TURBULENCE—Wingtipvortices that are created when anairplane generates lift. When anairplane generates lift, air spills overthe wingtips from the high pressureareas below the wings to the lowpressure areas above them. This flowcauses rapidly rotating whirlpools ofair called wingtip vortices or waketurbulence.

WASTE GATE—A controllablevalve in the tailpipe of an aircraftreciprocating engine equipped with aturbocharger. The valve is controlledto vary the amount of exhaust gasesforced through the turbochargerturbine.

WEATHERVANE—The tendency ofthe aircraft to turn into the relativewind.

WEIGHT—A measure of theheaviness of an object. The force bywhich a body is attracted toward thecenter of the Earth (or anothercelestial body) by gravity. Weight is

Glossary.qxd 5/7/04 10:46 AM Page G-17

G-18

WING AREA—The total surface ofthe wing (square feet), which includescontrol surfaces and may includewing area covered by the fuselage(main body of the airplane), andengine nacelles.

WING SPAN—The maximum distance from wingtipto wingtip.

WINGTIP VORTICES—The rapidly rotating air that spills overan airplane’s wings during flight. Theintensity of the turbulence depends onthe airplane’s weight, speed, andconfiguration. It is also referred to as

ZERO FUEL WEIGHT—The weight of the aircraft to includeall useful load except fuel.

ZERO SIDESLIP—A maneuver in atwin-engine airplane with one engineinoperative that involves a smallamount of bank and slightlyuncoordinated flight to align thefuselage with the direction of traveland minimize drag.

ZERO THRUST(SIMULATED FEATHER)—An engine configuration with a lowpower setting that simulates apropeller feathered condition.

wake turbulence. Vortices from heavyaircraft may be extremely hazardousto small aircraft.

WING TWIST—A design featureincorporated into some wings toimprove aileron control effectivenessat high angles of attack during anapproach to a stall.

YAW—Rotation about the verticalaxis of an aircraft.

YAW STRING—A string on the noseor windshield of an aircraft in view ofthe pilot that indicates any slipping orskidding of the aircraft.

Glossary.qxd 5/7/04 10:46 AM Page G-18

I-1

180° POWER-OFF APPROACH 8-23360° POWER-OFF APPROACH 8-2490° POWER-OFF APPROACH 8-21

AABSOLUTE CEILING 12-8ACCELERATED STALL 4-9ACCELERATE-GO DISTANCE 12-8ACCELERATE-STOP DISTANCE 12-8ACCURACY APPROACH 8-21

180° power-off 8-23360° power-off 8-2490° power-off 8-21

ADVERSE YAW 3-8AFTER LANDING 2-11

crosswind tailwheel 13-5roll 8-7tailwheel 13-4

AIMING POINT 8-8AIRCRAFT LOGBOOKS 2-1AIRFOIL TYPES 11-1AIRMANSHIP 1-1

skills 1-1AIRPLANE EQUIPMENT, Night 10-3AIRPLANE FEEL 3-2AIRPLANE LIGHTING, Night 10-3AIRPORT LIGHTING 10-4AIRPORT TRAFFIC PATTERN 7-1

base leg 7-3crosswind leg 7-4departure leg 7-4downwind leg 7-3entry leg 7-3final approach leg 7-3upwind leg 7-3

AIRWORTHINESS DIRECTIVES 2-1ALTERNATOR/GENERATOR 12-7ALTITUDE TURBOCHARGING 11-7ANTI-ICING 12-7APPROACH AND LANDING 8-1

after-landing roll 8-7base leg 8-1crosswind 8-15emergency 8-25estimating height and movement 8-4faulty 8-27final approach 8-2

go-around 8-11multiengine 12-14night 10-6normal 8-1roundout (flare) 8-5short-field 8-17soft-field 8-19stabilized approach 8-7touchdown 8-6turbulent air 8-17use of flaps 8-3

ATTITUDE FLYING 3-2AUTOPILOT 12-6AXIAL FLOW 14-5

B

BACK SIDE OF THE POWER CURVE 8-19BALLOONING 8-3, 8-30BANK ATTITUDE 3-2BASE LEG 7-3, 8-1BEFORE TAKEOFF CHECK 2-11BEST ANGLE OF CLIMB (VX) 3-13, 12-1

one engine inoperative (VXSE) 12-1BEST GLIDE SPEED 3-16BEST RATE OF CLIMB 3-13, 12-1

one engine inoperative (VYSE) 12-1BETA RANGE 14-7BLACK HOLE APPROACH 10-2BOUNCING 8-30BUS BAR 14-8BUS TIE 14-9BYPASS AIR 15-2BYPASS RATIO 15-2

C

CASCADE REVERSER 15-14CENTRIFUGAL COMPRESSOR

STAGE 14-5CHANDELLE 9-4CHECKLISTS, Use of, 1-6CIRCUIT BREAKER 14-9CLEAR OF RUNWAY 2-11CLIMB GRADIENT 12-8

Index.qxd 5/7/04 10:52 AM Page I-1

I-2

CLIMBS 3-13maximum performance 5-8night 10-5

COCKPIT MANAGEMENT 2-7COLLISION AVOIDANCE 1-4COMBUSTION CHAMBER 14-1COMBUSTION HEATER 12-6COMPLEX AIRPLANE 11-1COMPRESSION RATIO 15-1COMPRESSOR 14-1CONDITION LEVER 14-4CONES 10-1CONFINED AREA 16-4CONSTANT-SPEED PROPELLER 11-4

blade angle control 11-5governing range 11-5operation 11-5

CONTROLLABLE-PITCH PROPELLER 11-3CONVENTIONAL GEAR AIRPLANE 13-1CORE AIRFLOW 15-2CRAZING 2-2CRITICAL ALTITUDE 11-7CRITICAL MACH 15-7CROSS-CONTROL STALL 4-10CROSSWIND APPROACH

AND LANDING 8-13CROSSWIND COMPONENT 5-6CROSSWIND LEG 7-4CROSSWIND TAKEOFF 5-5CURRENT LIMITER 14-9

DDEICING 12-7DEPARTURE LEG 7-4DESCENTS 3-15

minimum safe airspeed 3-16partial power 3-16

DITCHING 16-1DOWNWASH 8-3DOWNWIND LEG 7-3DRAG DEVICES 15-13DRIFT 6-2DUCTED FAN 15-2

EEGT 11-8EIGHTS ACROSS A ROAD 6-11EIGHTS ALONG A ROAD 6-9EIGHTS AROUND PYLONS 6-11EIGHTS-ON-PYLONS 6-12ELEMENTARY EIGHTS 6-9ELEVATOR TRIM STALL 4-11ELT 2-1

EMERGENCIESabnormal instrument indications 16-11door open in flight 16-12electrical system 16-10engine failure 16-5fires 16-7flap failure 16-8landing gear malfunction 16-9loss of elevator control 16-9night 10-8pitot-static system 16-11VFR flight into IMC 16-12

EMERGENCY APPROACHAND LANDING 8-25

EMERGENCY DESCENTS 16-6EMERGENCY GEAR

EXTENSION SYSTEM 11-10EMERGENCY LANDINGS 16-1

airplane configuration 16-3psychological hazards 16-1safety concepts 16-2terrain selection 16-3terrain types 16-4

EMERGENCY LOCATORTRANSMITTER 2-1

ENGINE FAILURE AFTER TAKEOFF 16-5ENGINE FAILURE, MULTIENGINE

approach and landing 12-22during flight 12-21flight principles 12-23takeoff 12-18

ENGINE SHUTDOWN 2-12ENGINE STARTING 2-7ENTRY LEG 7-3EXHAUST GAS TEMPERATURE 11-8EXHAUST MANIFOLD 11-7EXHAUST SECTION 14-1

FFALSE START 14-10FAULTY APPROACHES 8-27

ballooning 8-30floating 8-29high final 8-27high roundout 8-28low final 8-27slow final 8-28

FEATHERING 12-3FEDERAL AVIATION ADMINISTRATION (FAA) 1-1FEEL OF THE AIRPLANE 3-2FINAL APPROACH 8-2FINAL APPROACH LEG 7-3FIRES

cabin 16-8electrical 16-7engine 16-7

Index.qxd 5/7/04 10:52 AM Page I-2

I-3

FIXED SHAFT ENGINE 14-3FLAP EXTENSION SPEED (VFE) 12-15FLAPS 11-1

effectiveness 11-2function 11-1operational procedures 11-2use of 8-3

FLARE 8-5FLIGHT CONTROLS 3-1FLIGHT DIRECTOR 12-6FLIGHT IDLE 14-7FLIGHT INSTRUCTOR, ROLE OF 1-3FLIGHT SAFETY 1-4FLIGHT STANDARDS DISTRICT

OFFICE (FSDO) 1-2FLIGHT TRAINING SCHOOLS 1-3FLOATING 8-29FORCED LANDING 16-1FORWARD SLIP 8-10FOUR FUNDAMENTALS 3-1FREE TURBINE ENGINE 14-5FUEL CONTROL UNIT 14-6FUEL CONTROLLER 14-1FUEL CROSSFEED 12-5FUEL HEATER 15-3

G

GAS GENERATOR 15-2GAS TURBINE ENGINE 14-1GLIDE 3-16GLIDE RATIO 3-16GO-AROUND (REJECTED LANDING) 8-11, 12-17GOVERNING RANGE 11-5GROUND BOOSTING 11-7GROUND EFFECT 5-7, 8-13GROUND INSPECTION 2-1GROUND LOOP 8-33, 13-6GROUND OPERATIONS 2-7GROUND REFERENCE MANEUVERS 6-1

drift and ground track control 6-2eights across a road 6-11eights along a road 6-9eights around pylons 6-11eights-on-pylons (pylon eights) 6-12rectangular course 6-4s-turns across a road 6-6turns around a point 6-7

GROUND ROLL 5-1GROUND TRACK CONTROL 6-2GROUNDSPEED 6-3HAND PROPPING 2-8HAND SIGNALS 2-7HIGH PERFORMANCE AIRPLANE 11-1HOT START 14-10

HUNG START 14-10HYDROPLANING 8-34

IILLUSIONS 10-2INITIAL CLIMB 5-1INTAKE MANIFOLD 11-7INTEGRATED FLIGHT INSTRUCTION 3-3INTENTIONAL SPIN 4-15INVERTER 14-8JET AIRPLANE 15-1

approach and landing 15-19low speed flight 15-10pilot sensations 15-15rotation and lift-off 15-18stalls 15-10takeoff and climb 15-16touchdown and rollout 15-24

JJET ENGINE 15-1

efficiency 15-5fuel heater 15-3ignition 15-3operating 15-2

K

KINESTHESIA 3-2

LL/DMAX 3-16LANDING GEAR

controls 11-10electrical 11-9electrohydraulic 11-9emergency extension 11-10hydraulic 11-9malfunction 16-9operational procedures 11-12position indicators 11-10retractable 11-9 safety devices 11-10tailwheel 13-1

LATERAL AXIS 3-2LAZY EIGHT 9-6LEVEL FLIGHT 3-4LIFT-OFF 5-1LIFT-OFF SPEED (VLOF) 12-1

Index.qxd 5/7/04 10:52 AM Page I-3

I-4

LONGITUDINAL AXIS 3-2LOSS OF DIRECTIONAL

CONTROL DEMONSTRATION 12-27

M

MACH 15-7MACH BUFFET BOUNDARIES 15-8MACH TUCK 15-7MANEUVERING SPEED 9-1MAXIMUM OPERATING SPEED 15-6MAXIMUM PERFORMANCE

CLIMB 5-8MAXIMUM SAFE

CROSSWIND VELOCITIES 8-16MINIMUM CONTROL SPEED (VMC) 12-2MINIMUM CONTROLLABLE

AIRSPEED 4-1MINIMUM DRAG SPEED 4-2MULTIENGINE AIRPLANE 12-1

approach and landing 12-14crosswind approach and landing 12-16engine failure during flight 12-21engine failure on takeoff 12-18fuel crossfeed 12-5go-around 12-17ground operation 12-12level off and cruise 12-14one engine inoperative approach and landing 12-22

propeller 12-3propeller synchronization 12-5rejected takeoff 12-18short-field operations 12-16slow flight 12-25stalls 12-25 takeoff and climb 12-12weight and balance 12-10

MUSHING 3-2

N

NIGHT OPERATIONSairplane equipment 10-3airplane lighting 10-3airport and navigation lighting aids 10-4approach and landing 10-6emergencies 10-8illusions 10-2orientation and navigation 10-6pilot equipment 10-3preparation and preflight 10-4start, taxi, and runup 10-5takeoff and climb 10-5

NIGHT VISION 10-1NOISE ABATEMENT 5-11NORMAL TAKEOFF 5-2NOSE BAGGAGE COMPARTMENT 12-7

OONE-ENGINE-INOPERATIVE SPEED (VSSE) 12-1OVERBANKING TENDENCY 3-9OVERBOOST CONDITION 11-9OVERSPEED 15-8

PPARALLAX ERROR 3-11PARKING 2-11PILOT EQUIPMENT, Night 10-3PILOT EXAMINER, Role of 1-2PITCH AND POWER 3-19PITCH ATTITUDE 3-2PIVOTAL ALTITUDE 6-14PORPOISING 8-31POSITION LIGHTS 10-3POSITIVE TRANSFER OF CONTROLS 1-6POSTFLIGHT 2-12POWER CURVE 8-19POWER LEVER 14-4PRACTICAL SLIP LIMIT 8-11PRACTICAL TEST STANDARDS (PTS) 1-4PRECAUTIONARY LANDING 16-1PREFLIGHT INSPECTION 2-2PRESSURE CONTROLLER 11-7PROPELLER 11-3, 12-3PROPELLER BLADE ANGLE 11-4

control 11-5PROPELLER CONTROL 11-4PROPELLER SYNCHRONIZATION 12-5PSYCHOLOGICAL HAZARDS 16-1PYLON EIGHTS 6-12

RRADIUS OF TURN 3-10RECTANGULAR COURSE 6-4REGION OF REVERSE COMMAND 8-19REJECTED LANDING 8-11REJECTED TAKEOFF 5-11, 12-18RETRACTABLE LANDING GEAR 11-9

approach and landing 11-13controls 11-10electrical 11-9electrohydraulic 11-9emergency extension 11-10hydraulic 11-9

Index.qxd 5/7/04 10:52 AM Page I-4

I-5

operational procedures 11-12position indicators 11-10safety devices 11-10takeoff and climb 11-13transition training 11-14

REVERSE THRUST 14-7RODS 10-1ROTATING BEACON 10-4ROTATION 5-1ROTATION SPEED (VR) 12-1ROUGH-FIELD TAKEOFF 5-10ROUNDOUT 8-5

ballooning 8-3floating 8-29high 8-28late or rapid 8-29

RUNWAY INCURSION 1-5RUNWAY LIGHTS 10-4

S

SAFETY CONCEPTS 16-2SECONDARY STALL 4-9SECURING 2-12SEGMENTED CIRCLE 7-3SERVICE CEILING 12-8SERVICING 2-12SHORT-FIELD

approach and landing 8-17tailwheel 13-3takeoff 5-8

SIDESLIP 5-6, 8-10SINK RATE 16-3SKID 3-8SLIP 3-8, 8-10SLOW FLIGHT 4-1, 12-25SOFT FIELD

approach and landing 8-19tailwheel 13-4takeoff 5-10

SPEED BRAKE 15-13SPEED INSTABILITY 4-2SPIN AWARENESS 12-26SPINS 4-12

developed phase 4-14entry phase 4-13incipient phase 4-13intentional 4-15procedures 4-13recovery phase 4-14weight and balance requirements 4-16

SPLIT SHAFT ENGINE 14-5SPOILERS 15-13SQUAT SWITCH 11-10STABILIZED APPROACH 8-7, 15-21STALL AWARENESS 1-6

STALLS 4-3accelerated 4-9characteristics 4-6cross-control 4-10elevator trim 4-11imminent 4-6jet airplane 15-10multiengine 12-25power-off 4-7power-on 4-8recognition 4-3recovery 4-4secondary 4-9use of ailerons/rudders 4-5

STEEP SPIRAL 9-3STEEP TURNS 9-1STRAIGHT FLIGHT 3-5STRAIGHT-AND-LEVEL FLIGHT 3-4S-TURNS ACROSS A ROAD 6-6

TTAILWHEEL AIRPLANES 13-1

crosswind landing 13-5crosswind takeoff 13-3short-field landing 13-6short-field takeoff 13-3soft-field landing 13-6soft-field takeoff 13-4takeoff 13-3takeoff roll 13-2taxiing 13-1touchdown 13-4wheel landing 13-6

TAKEOFFcrosswind 5-5ground effect 5-7multiengine 12-2night 10-5normal 5-2rejected 5-11roll 5-1short field 5-8soft/rough field 5-10tailwheel 13-3tailwheel crosswind 13-3tailwheel short-field 13-3tailwheel soft-field 13-4

TARGET REVERSER 15-14TAXIING 2-9

tailwheel 13-1THRUST LEVER 15-4THRUST REVERSERS 15-14TOUCHDOWN 8-6

bounce 8-30crab 8-32drift 8-32

Index.qxd 5/7/04 10:52 AM Page I-5

I-6

ground loop 8-33hard landing 8-32porpoise 8-31tailwheel 13-4wheelbarrowing 8-32wing rise 8-33

TRACK 6-2TRAFFIC PATTERN INDICATOR 7-3TRANSITION TRAINING

complex airplane 11-14high performance airplane 11-14jet powered airplanes 15-1multiengine airplane 12-31tailwheel airplanes 13-1turbopropeller powered airplanes 14-12

TRANSONIC FLOW 15-7TRIM CONTROL 3-6TURBINE INLET TEMPERATURE 11-8TURBINE SECTION 14-1TURBOCHARGER 11-7

failure 11-9heat management 11-8operating characteristics 11-8

TURBOFAN ENGINE 15-2TURBOPROP AIRPLANE 14-1

electrical system 14-8operational considerations 14-10

TURBOPROP ENGINES 14-2TURBULENT AIR APPROACH

AND LANDING 8-17TURNS 3-7

climbing 3-15coordinated 3-9gliding 3-18level 3-7medium 3-7

shallow 3-7steep 3-8

TURNS AROUND A POINT 6-7

UUPWIND LEG 7-3

VVFR FLIGHT INTO

IMC CONDITIONS 16-12VISUAL GROUND INSPECTION 2-1V-SPEEDS 12-1, 15-16, 15-19

W WASTE GATE 11-7WEATHERVANE 5-5WEIGHT AND BALANCE 12-10WHEEL LANDING 13-6WHEELBARROWING 5-9, 8-17, 8-32WINDSOCK 7-3WINGTIP WASHOUT 4-5

Y

YAW 3-2YAW DAMPER 12-6

Index.qxd 5/7/04 10:52 AM Page I-6