1/28 Jet Safety International– Control / performance Flight Introduction to Control / Performance Flight Introduction to Control / Performance Flight

1/28Jet Safety International– Control / performance Flight

Introduction to

Control / Performance

Flight

Introduction to

Control / Performance

Flight


Aircraft attitude is the relationship of its longitudinal and lateral axes to the Earth's horizon. An aircraft is flown by controlling the attitude and power as necessary to produce the desired performance. This is known as the "control and performance concept" of attitude instrument flying and can be applied to any basic flight maneuver.

GeneralGeneralBASIC INSTRUMENT FLYING-FIXED WING


There are two basic situations that can exist when describing flight of airplanes which will change the methods of controlling the aircraft. For that reason, it becomes very important to understand the POWER CONDITION that you are operating in.

Power ConditionsPower Conditions


There are only TWO basic power conditions for flight. They are known as POWER CONDITION I, and POWER CONDITION 2.



Power Condition 1 (PC1) - power is available and variable.

This means that, at the discretion of the pilot, power may be adjusted or changed.

This can also be defined as when the flight path angle, altitude or rate of climb or descent of the aircraft is fixed or constant, and the power is variable.


Power Condition 1Power Condition 1


Some examples of Power Condition 1 (PC1) are

Level Flight (Fixed Altitude)Normal Approach visual approach to Landing (Fixed Flight Path - On VASI or aim-point)ILS approach (Fixed Flight Path - On Glide-slope)Normal Descents

"Note: Normal descents are descents with power set to any position EXCEPT idle power.




Power Condition 2 (PC2) - power is fixed by choice or by accident.

This means that if the pilot sets the power to a fixed position, such as MAX POWER, CLIMB POWER or IDLE POWER, or if the power is fixed by accident such as an engine failure, you are operating in PC2.

This can also be defined as when the power is fixed and the flight path is variable.




Some examples of Power Condition 2 (PC2) are:

Take-off (Fixed Power at Max Or Predetermined Limit)

Power Off Situations (Fixed Power - by Accident)Idle Power Descents" (Fixed Power At Idle - by Choice)

"Note: Power idle descents (by choice) are not very common when operating reciprocating engines. It

is important to realize that this condition does exist and is more common in jet powered aircraft flying.




When operating in PC2:

Pitch Controls Either Airspeed, Vertical Velocity OR Flight Path Angle.

When operating in PC2, the only variable that can be manipulated is PITCH. It is also reasonable to assume that since we only have one variable (pitch) we can only have one controlled output.

That is why pitch controls EITHER airspeed OR vertical velocity, but not BOTH SIMULTANEOUSLY.




Now that you understand the Power Conditions, you can examine the exact methods of accurate aircraft control. In order to do this, we must discuss the three control inputs that allow you to control the airplane. These are known as the CONTROL PARAMETERS.

There are three Control Parameters that allow you to control altitude, heading and airspeed. They are:

PITCH CONTROL BANK CONTROL POWER (THRUST) CONTROL

"Note: Yaw or rudder is not considered a control parameter in - flight because its only purpose is to compensate adverse yaw either from aileron usage or from asymmetric thrust situations.

Control ParametersControl Parameters


In a light single engine airplane, an increase in thrust will increase tail down force, an cause a PITCH UP tendency.

Specific Flight CharacteristicsSpecific Flight Characteristics


In a light single engine airplane, an decrease in thrust will decrease tail down force, an cause a PITCH DOWN tendency.



In a light MULTIENGINE TRAINER equipped with a “T - TAIL” an increase or decrease in thrust will have little effect on PITCH because the tail flies in free dynamic pressure.


Free Q (dynamic pressure)


In a high performance BUSINESS JET, an increase or decrease in thrust will have A REVERSE EFFECT on PITCH because the CENTER OF THRUST is above the CENTER OF GRAVITY.

That is an increase in thrust will cause a PITCH DOWN, and a decrease in thrust will cause a PITCH UP.


Free Q (dynamic pressure)

Center of Gravity


SPECIFIC FLIGHT CHARACTERISTCS, ARE NOT METHODS OF CONTROL.

IN power condition 1

FLY PITCH to FLIGHT PATH ANGLE, THRUST TO AIRSPEED, &

TRIM THE CONTROL PRESSURE TO NEUTRAL.



After Takeoff - Power Condition 2After Takeoff - Power Condition 2Pitch & Bank Control

Pitch Performance

Bank Performance

Power Fixed by Choice


Straight & Level - Power Condition 1Straight & Level - Power Condition 1Pitch & Bank Control Pitch Performance

Power Performance

Power Control

Bank Performance


Level Turn - Power Condition 1Level Turn - Power Condition 1Pitch & Bank Control Pitch Performance

Power Performance

Power Control

Bank Performance


Steep Turn - Power Condition 1Steep Turn - Power Condition 1Pitch & Bank Control Pitch Performance

Power PerformanceBank Performance

Power Control


Constant Rate Descent - Power Condition 1Constant Rate Descent - Power Condition 1Pitch & Bank Control

Pitch PerformanceBank Performance

Power Control

Power Performance


Thrust / Drag CurveThrust / Drag Curve

L/D max - Jet

L/D max - Prop



Back Side - Region of ReverseCommand - NOTPerformance - YES

Front Side



Back Side - Region of ReverseCommand - NOTPerformance - YES

Front Side

COMMAND IS CONTROL IT IS DYNAMIC - A CHANGE IN SOMETHING

PERFORMANCE IS STEADY STATE NOTHING IS CHANGING

CONTROL - IT TAKES LESS THRUST TO TO DECELERATE

PERFORMANCE - IT TAKES MORE THRUST TO MAINTAIN A SLOWER SPEED


Slow Flight - Power Condition 1Slow Flight - Power Condition 1Pitch & Bank Control Pitch Performance

Bank Performance

Power Control

Power Performance


Cockpit View - Landing Cockpit View - Landing

Aim Point - Pitch

Thrust - Aispeed

Lower Rear Anatomical reference


END OF CONTROLPERFORMANCEINTRODUCTION

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1/28 Jet Safety International– Control / performance Flight Introduction to Control / Performance Flight Introduction to Control / Performance Flight