ACC Module14

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Body of Knowledge Module 14

Airport Operations And Federal Aviation Regulation

Part 139—Certification



These modules were originally written by Stephen Quilty, A.A.E., and have been updated

by the AAAE BOE, AAAE staff, and industry experts.

2004/2005

@All Rights Reserved

American Association of Airport Executives



ContentsModule Objectives ................................................................................................ 1

Airport Certification ............................................................................................. 2

FAR Part 139 .................................................................................................. 2

Airport Certification Manual .................................................................. 3

Requirements and Contents of an ACM ..................................................4Airport Self-Inspection ................................................................................... 7

Pavement Surfaces .......................................................................................... 8

Pavement Condition and Inspection ........................................................9

Pavement Skid-Resistance .....................................................................11

Pavement Friction Measurement ...........................................................13

Movement and Safety Areas.........................................................................14

Markings, Signs and Lighting ......................................................................15

Airfield Lighting .................................................................................... 16

Airfield Signs ......................................................................................... 17

Airfield Markings ..................................................................................19

Snow and Ice Control.............................................................................23Snow and Ice Plan ........................................................................................ 24

De-ice and Anti-ice Compounds............................................................25

Aircraft De-icing .................................................................................... 26

Snow Removal Equipment ...........................................................................28

Rotary Snowblowers..................................................................................... 28

Snow Plows ............................................................................................ 28

Sweepers ................................................................................................ 29

Material Spreaders ........................................................................................ 30

Snow and Ice Removal Techniques ....................................................... 30

Airport Condition Reporting ........................................................................32Notices to Airman (NOTAM). ...............................................................32

Airport Construction Activity ................................................................34

Pedestrians and Ground Vehicles .................................................................35

Public Protection .......................................................................................... 35

Wildlife Hazard Management.......................................................................36

Summary.......................................................................................................40

Study Questions ............................................................................................ 43

TablesTable A: Subpart D-Operations .............................................................................................. 5

Table B: Runway Marking Elements ................................................................................... 19

Figures

Figure 1: Signing Examples for a Complex Airport ............................................... 18

Figure 2: Runway Markings ................................................................................... 20

Figure 3: Special Runway Markings ....................................................................... 20

Appendix A: Standard for Airport Sign System ......................................................................... 41

Appendix B: ACM Elements - Section 139.203 (B) .................................................................. 42



Module Objectives

Can you....

1. identify the certification requirements as stipulated in FAR Part 139?

2. distinguish the four classes of airports as defined by the most recent FAR Part 139?

3 explain what purpose an airport certification manual (ACM)serves, what it

should provide, and what it should emphasize?

4. identify the key components of an airport safety self-inspection program and the

types of activities they address?

5. identify those factors that affect pavement strength and wear and how to

mitigate deterioration?

6. explain the effects of poor pavement conditions on aircraft and how pave-

ment traction and friction can be maintained and improved?

7. explain how pavement conditions are measured and the effect of different

readings?

8. delineate the movement and safety areas of an airport and the criteria that

affects them?

9. identify the different types of approach lighting systems that exist and their

operating criteria?

10. identify the marking and signage requirements at airports and delineate their

inscriptions or color?

11. describe the effects of snow and ice on pavement surfaces and the responsibility

of airport operations to mitigate their effects?

12. explain the purpose of snow and ice plans and their basic components?

13. explain the various methods and timing for removing snow and ice from

pavement surfaces?

14. describe the basic properties of anti-ice and de-ice compounds?

15. identify when and what information is conveyed in a NOTAM?

16. determine when to conduct a Wildlife Hazard Assessment at an airport and

strategies for resolving or mitigating wildlife hazards?

17. explain the acronyms, terms, and common phrases used in the module?

18. interpret and explain the basic concepts presented in the various tables?

1



Airport Certification

The heart and soul of any airport organization is Airport Operations. The opera-

tions departments of most airports were created following the promulgation of

federal airport certification in the early 1970’s. Prior to this regulation, airport

maintenance departments generally performed airfield inspections and then

repaired any deficiencies found. The formal certification program now requiresthe operating departments to keep the airport functioning safely and efficiently.

These responsibilities include daily inspections; reporting of problems; inform-

ing tenants, users, and staff of current conditions; monitoring corrections and the

coordination of overall activities.

The Federal Aviation Administration (FAA) has the statutory authority, originally

approved by Congress in the Airport and Airways Development of 1970, to issue

Airport Operating Certificates (AOCs) to airports serving certain air carriers and

to establish minimum airport safety standards. This authority has been codified

in the Code of Federal Regulations as Part 139, Certification of Airports.

Under the most recent revision to FAR Part 139, airports that are served by

scheduled air carrier aircraft designed for more than 9 passenger seats or airports

serving unscheduled air carrier aircraft designed for at least 31 passenger seats

are subject to certification and annual safety inspection. All federally certified

airports are required to be operated and maintained in a safe and serviceable

condition in accordance with minimum standards required or prescribed in Part

139. The purpose of these inspections is to determine compliance with regulatory

safety standards.

FAR Part 139

In 2004, the FAA, as directed by Congress in the Aviation Investment and Re-

form Act for the 21st century (Air 21-Public Law 106-181), issued revised rules

for the certification of airports. The new regulations expanded and clarified

existing requirements by reclassifying airports into four categories according to

the type of air carrier operations.

The term air carrier aircraft was redefined to include large air carrier aircraft and

small air carrier aircraft. An aircraft that is being used by an air carrier is catego-rized as large if it is designed for at least 31 passenger seats and small if de-

signed for more than 9 seats but fewer than 31 seats.

The four classes of airports defined by Part 139 are as follows:

Class I is an airport certificated to serve scheduled operations of large air

carrier aircraft. It can also serve unscheduled passenger operations of large

air carrier aircraft and/or scheduled operations of small air carrier aircraft.

Objective 1

Airports that are served by scheduled air carrier

aircraft designed for

more than 9 passenger

seats or airports serving

unscheduled air carrier

aircraft designed for at

least 31 passenger seats

are subject to certifica-

tion and annual safety

inspection.

The new FAA regula-

tions expanded and

clarified existing

requirements by

reclassifying airports

into four categories

according to the type of

air carrier operations.

Air carrier aircraft was

redefined to include

large air carrier aircraft

(designed for at least31 passenger seats) and

small air carrier aircraft

(designed for more

than 9 seats but fewer

than 31 seats).

Objective 2

2



ACM —Airport

Certification Manual

Objective 3

Class II is an airport certificated to serve scheduled operations of small air

carrier aircraft and the unscheduled passenger operations of large air carrier

aircraft. This class may not serve scheduled large air carrier aircraft.

Class III is an airport certificated to serve scheduled operations of small air

carrier aircraft. This class may not serve scheduled or unscheduled large air

carrier aircraft.

Class IV is an airport certificated to serve unscheduled passenger opera-

tions of large air carrier aircraft. This class may not serve scheduled large

or small air carrier aircraft.

An air carrier operation is a takeoff or landing of an air carrier aircraft. It

includes the period of time from 15 minutes before until 15 minutes after

the takeoff or landing.

All airports in each class that are certificated under Part 139 must prepare

and operate under an Airport Certification Manual (ACM) approved by theFAA. The ACM is structured to help an airport comply with the statutory

requirements. The intent of the ACM is to provide necessary information to

personnel who are responsible for operating the airport or who are affected

by the regulations.

Air carriers are specifically precluded from using an airport for operations

that is not Part 139-certificated, and an airport is required to have an Air-

port Operating Certificate in order to accommodate air carrier activity.

Exceptions to the rule that may allow the use of a noncertificated airport

involve cases of an aircraft emergency, training flights, or an airport ap-

proved as an air carrier alternate.

Airport Certification Manual

Because Part 139 is written in broad terms to accommodate all airports cov-

ered by the regulation, it does not define how an airport is to be operated. It is

the ACM that functions as an extension of the Federal Regulations and pro-

vides the bridge between the general requirements of Part 139 and the applica-

tion at each airport, taking into account the airport’s specific site, activity, and

configuration. By requiring an airport to develop an ACM, the FAA places the

burden and responsibility for compliance on the airport operator. The FAAthen administers Part 139 by enforcing the contents of the approved ACM.

The ACM should provide enough direction to achieve compliance with the

regulation but not be so detailed as to lack operational flexibility or result in

constant violation of the manual. It is suggested that airport management’s

approach be comprehensive yet conservative. Only details necessary to show

how regulatory compliance is to be achieved is required. A good path for airport

3



management to take is to write the ACM as though they are leaving instructions

for someone to carry out.

When developing, writing, or revising the ACM, emphasis is placed on estab-

lishing responsibility, authority, and procedures for Part 139 compliance. This

is accomplished by identifying who is going to perform the tasks, what the

tasks will be, how the tasks are to be performed, and when they will be accom-

plished. Beyond that, excessive levels of detail can restrict the flexibility of

airport personnel to meet unforeseen circumstances, or even create unnecessary

commitments under the regulation. This is because, upon approval, the ACM

becomes a document with considerable legal significance.

Part 139 requires airport management to furnish all applicable portions of the

airport’s ACM to those airport personnel responsible for its implementation. It

is not intended that the ACM provide complete instructions on how to do a job.

If the ACM is well prepared and followed, it will result in job performance that

maintains the airport in regulatory compliance.

Requirements and Contents of an ACM

As a working document that reflects an airport’s current condition and opera-

tion, changes to the certification manual or specifications are to be expected.

Part 139 requires that the ACM be typewritten or printed, but it is not specific

on the form or material. However, it should be in a format that is easy to revise.

The ACM is normally bound in a loose-leaf, standard size, three-ring binder so

it can be easily organized and maintained. The FAA requires that each page

show the approval date, either as part of the original document or as a revision

or addition.

Either the certificate holder or the FAA through the Regional Airports Division

Manager may initiate an amendment to the ACM. Amendments to the ACM

should be submitted to the FAA 30 days before their effective date.

An airport may petition the FAA for an exemption from any Part 139

requirement. A request for an exemption becomes a rulemaking action and

requires the submittal of information demonstrating that compliance with

the requirement would be unreasonably costly, burdensome, or impractical.

If approved, an exemption issued to an airport effectively changes the

manner in which the airport complies with its operating certificate.

On occasion, an airport may be faced with a situation that could result in a

deviation from the regulations. Whether the deviation results in an actual

violation depends on the circumstances involved. Under Part 139, any

deviation requires that airport management inform the FAA not later than

14 days of the occurrence. Deviations are permitted in circumstances that

primarily emanate from an aircraft emergency. For example, if as the result

of an onboard safety problem, an air carrier used a runway that did not meet

What to emphasize

when developing,

writing, and revising

ACM—establish

responsibility,

authority, and proce-dures for Part 139

compliance

Amendments to theACM — must be

submitted 30 days

before the effective

date.

Under Part 139, an

airport manager must

inform the FAA of a

deviation from

regulations not later

than 14 days of the

occurrence.

An example of

violation of regula-

tions—Allowing air

carrier operations

while the airport’s

firefighting equipment

is participating in an

off-airport training

exercise.

4



the safety requirements of the ACM. This type of deviation from a regula-

tion may be acceptable because of the emergency circumstances. However,

the allowing of air carrier operations while the airport’s firefighting equip-

ment is participating in an off-airport training exercise is not a deviation,

but a violation.

A few sections of Part 139 demand actions beyond the authority of the airport

operator. Qualifying language such as “to the extent practicable” or “which

agrees to provide” highlights these sections and targets an attempt to achieve the

desired result. Examples are obstruction lights outside airport boundaries or

medical assistance and transportation from community resources.

Each airport, in accordance with its specific classification, must include in its

ACM a description of the operating procedures, facilities and equipment, re-

sponsibility assignments and other related information needed by key personnel

to comply with the applicable provisions of Subpart D—Operations. Table A

lists the major elements included in Subpart D.

The regulations also describe the specific manual elements for each class of

airports. See Appendix B.

Each airport, in accor-

dance with its specific

classification, must

include in its ACM a

description of the

operating procedures,

facilities and equipmen

responsibility assign-

ments and other relate

information needed by

key personnel to compl

with the applicable

provisions of Subpart

Table A: Subpart D—Operations

Section 139.301 Records.

Section 139.303 Personnel.

Section 139.305 Paved Areas.

Section 139.307 Unpaved Areas.

Section 139.309 Safety Areas.

Section 139.311 Marking, signs and lighting.Section 139.313 Snow and ice control

Section 139.315 ARFF: Index determination.

Section 139.317 ARFF: Equipment and agents.

Section 139.319 ARFF: Operational requirements.

Section 139.321 Handling and storing of hazardous substances and materials.

Section 139.323 Traffic and wind direction indicators.

Section 139.325 Airport emergency plan.

Section 139.327 Self-inspection program.

Section 139.329 Pedestrians and Ground Vehicles.

Section 139.331 Obstructions.

Section 139.333 Protection of Navaids.

Section 139.335 Public Protection.Section 139.337 Wildlife hazard management.

Section 139.339 Airport condition reporting.

Section 139.341 Identifying, marking and lighting construction and other unserviceable areas.

Section 139.343 Noncomplying conditions.

5



The FAA Airport Certification Branch annually inspects all Part 139 airports.

However, FAR Part 139 authorizes FAA to inspect at any time.

The FAA requires airports to employ sufficiently qualified personnel to operate the

airport in a safe manner. This regulation is met if all the requirements in the ACM are

properly performed. Those individuals who are authorized to carry out the responsi-

bilities of ACM compliance are specifically identified, and they are required to be

well trained and educated in the requirements. Training records for operating and

emergency personnel must be kept for twenty-four consecutive calendar months.

The section on paved areas includes several specific requirements for surfaces

available only for air carrier use. Outside of Alaska a section on unpaved areas is

not frequently found in an ACM. Safety areas were redefined to include runway

or taxiway areas and the surrounding surfaces that are prepared or suitable for

reducing the risk of damage to an aircraft in the event of an undershoot, over-

shoot, or excursion from a runway or unintentional departure from a taxiway.

Because different criteria exist for the type of aircraft landing approaches to anairport, the section on marking, signs, and lighting reflects the requirements for

runways and taxiways to fulfill the criteria. Weather conditions may also affect

safe air carrier operations, and therefore snow and ice control is addressed.

Three sections under Part 139 address the airport’s responsibilities for aircraft

rescue and firefighting (ARFF). The sections detail the level of ARFF response

necessary, the type of equipment and agents appropriate, and the performance

requirements for ARFF response.

The handling and storage of hazardous substances and materials are also covered.

Hazardous materials include two different situations found at airports—oneconcerns hazardous materials such as aircraft cargo, and the other concerns

hazardous materials in the form of fuels that are for the operation of the aircraft

and are not considered cargo.

Part 139 airports are required to have traffic and wind direction indicators that

assist a pilot in determining safe conditions for landing or taking off.

In the event of emergencies, certificated airports must have a detailed emergency

plan to respond to the situation. The section on Airport Emergency Plans (AEP)

contains technical information that helps airport management develop an AEP.An AEP addresses several different conditions besides an aircraft emergency.

The section on an airport’s self-inspection program is very important because it

affects so many other areas of Part 139 compliance. It identifies what needs to be

monitored in order to be in compliance with the regulations.

The safety requirements for ground vehicles operating on the airfield and termi-

nal areas and the responsibilities of airport management to monitor obstructions

that fall within the airport’s authority must be described within the ACM. A

The safety area

section refers to

requirements for the

areas of and immedi-

ately surrounding the

runway and taxiway

surfaces.

Three sections under Part 139 address the

airport’s responsibili-

ties for aircraft rescue

and firefighting

(ARFF): (1) the level

of ARFF response

necessary, (2) the type

of equipment and

agents appropriate,

and (3) the perfor-

mance requirements

for ARFF response.

ARFF—aircraft

rescue and firefighting

6

Part 139 certificated

airports are required to

have traffic and wind

direction indicators

that assist a pilot in

determining safe

conditions for landingor taking off.

AEP—Airport

Emergency Plan

addresses several

different conditions

besides an aircraft

emergency.



separate section covers the requirement to protect navaids from electrical inter-

ruption, signal interference, and vandalism. Partly for these reasons, the FAA

stipulates that airports prevent inadvertent entry into an area containing hazards

for the unwary trespasser under the section on public protection.

If wildlife activity exists or can exist in or around an airport, the activity can have serious

consequences for the safe operation of aircraft. As a result, sections on how to address

wildlife hazard assessment and the reporting of a specific problem is required.

In order to ensure safe airport operations during periods of construction or

maintenance, airport managers are required to identify, mark, and report con-

struction or other unserviceable areas as they exist on the airport. More detailed

information on several of the ACM requirements follows in the paragraphs

below. Many special advisory circulars exist for each of the sections identified.

Guidelines and standards may be obtained through the FAA Regional or Local

Airports District Offices, FAA’s and AAAE’s Internet Web sites, the Government

Printing Office, and airport seminars and workshops.

Airport Self-Inspection

Regular self-inspections of the airport for hazardous conditions or those which

have the potential to become hazardous are the most critical actions that can be

taken to ensure the safety of airport operations. The airport manager’s primary

responsibility is to implement self-inspection and corrective procedures.

Primary attention in a self-inspection is given to operational items such as pavement

areas, safety areas, markings and signs, lighting, aircraft rescue and firefighting,fueling operations, navigational aids, ground vehicles, obstructions, public protection,

wildlife hazard management, construction, and snow and ice control. Inspection of

areas which have been assigned to individual air carriers, fixed-base operators, or

other tenants can be made the responsibility of the user, but airport management is

required to retain overall inspection supervision. This is because airport management

cannot delegate responsibility for operating the airport safely.

A successful safety self-inspection program has four key components:

(1) Regularly scheduled inspections of airport operating areas at least daily or

more often if operational activities or airfield lighting systems warrant.

(2) Continuous surveillance of certain airport activities such as fueling, construc-

tion, and airfield maintenance.

(3) Periodic evaluation of approach slopes, obstructions, or other activities and

facilities. The time interval could be weekly, monthly, or quarterly, depending

on the activity or facility.

(4) The monitoring of issues such as changing weather, high flight activity,

wildlife migration, or receipt of a complaint.

Regular self-inspec-

tions of the airport are

the most critical

actions that can be

taken to ensure the

safety of airport

operations.

7

Objective 4

An inspection of the

approach slope

surfaces for tree

growth would require

periodic evaluation.

If a control tower

reports a flock of birds

in the area, it is

necessary to conduct a

special inspection.

Such airport activities as

fueling, construction, and

airfield maintenance

require continuous

surveillance.

A special event such

as the arrival of the

President of the

United States requires

special inspection.



Part 139 requires that inspectors be given initial and recurrent training regarding

the self-inspection program used by the airport. The regulation also defines the

items on which the individuals must be trained. All training records for inspec-

tors must be kept for a 24-month period.

At certificated airports, inspections are necessary before the first air carrier

operation in the morning, upon any major change in airport surface conditions,

when braking action reports by pilots or others are stated to be deteriorating, and

after an incident or accident. Other inspections may be required by the ACM or a

construction safety plan.

An effective safety inspection program establishes deficiency-reporting proce-

dures for prompt correction. This includes a checklist of items to be inspected, a

dissemination plan for informing others of the hazards, a work order system to

correct the deficiencies, and a maintenance log for monitoring the status and

currency of the process. Certificated airports must retain the regularly scheduled

inspection checklists for at least twelve consecutive calendar months.

Pavement Surfaces

The airport’s paved surfaces are included in a self-inspection program. Pavement

falls within two general categories: flexible or rigid. Flexible pavements such as

asphalt, dirt, or grass tend to compress under load, while rigid pavement resists

such compressibility. Portland cement concrete (PCC) is an example of a rigid

paved surface.

The two types of pavement, asphalt and concrete, have different characteristics.Asphalt can be laid without expansion joints or seams and is generally less

expensive than concrete to install, but requires higher maintenance. Since asphalt

is primarily a petroleum product, it is susceptible to oxidation from the sun’s

ultraviolet rays and the solvent action of fuel or oil. Being more rigid, concrete is

poured into distinctive slabs that require seams or joints to allow for expansion

and contraction. This contributes to its higher cost. The advantage of concrete,

however, is that it can withstand much higher aircraft loads than an equivalent

thickness of asphalt. It also resists weathering and oil or fuel spillage.

The wear characteristics and longevity of any pavement surface will be

affected by a number of different factors. When designing pavement surfaces,engineers consider:

Type of load (critical aircraft: utility, transport, military)

Distribution of load (landing gear type: single, dual, tandem)

l Volume and frequency of load (how often load is imposed)

Material quality (ratio of cement and stone or asphalt and bituminous aggregate)

Climatic effects (temperature variations, type of weather)

Mix of traffic (demands by different types of aircraft)

Under Part 139,

inspectors must

receive training and

all training records for

inspectors must be

kept for a 24-month

period.

At certificated

airports, inspections

are necessary before

the first air carrier

operation in the

morning, upon any

major change in

airport surface

conditions, when

braking action reports

by pilots or others are

stated to be deteriorat-ing, and after an

incident or accident.

8

Certificated airports

must retain the

regularly scheduled

inspection checklists

for at least twelve

consecutive calendar

months.

Asphalt can be laid

without expansion

joints or seams.

Compared with

asphalt, concrete is

more rigid, but it can

withstand much

higher aircraft loads

than an equivalent

thickness of asphalt.

Objective 5



Roughness (smooth, coarse, porous)

Maintenance capabilities (preventive, routine, sealing)

Of the above factors, the two major elements contributing to pavement deteriora-

tion are weathering and imposed loads. The most detrimental factor to a paved

surface is water which seeps through and erodes the sub-base material. The water

weakens the supportive pavement resulting in pavement breakup.

General aviation pavement surfaces can suffer the same consequences, even

though they experience lighter loads, because the pavement is designed to carry

the most demanding aircraft expected to use the facility. Any sub-base deteriora-

tion, therefore, will result in normal loads now exceeding the pavement’s ability

to support them. Pavement potholes are typically formed when loads are imposed

over a pavement sub base area, weakened by water erosion.

Pavement Condition and Inspection

Part 139 requires that airport management maintain and promptly repair any

pavement surface available for air carrier use. If the airport is not certificated, any

pavement surface using federal grant dollars requires a similar level of response.

Airport management’s obligation is to prevent the overstressing of airport pave-

ments. Should pavement failure occur because the airport allowed aircraft opera-

tions that exceeded the pavement limitations, the cost to restore the pavement to

satisfactory condition may not be eligible for federal funding.

Acceptable aircraft weights are identified in the runway data table on the

airport layout plan. The ACN-PCN system of classification provides a stan-

dardized international airplane/pavement rating system replacing the variousS (single), D (dual), T (tandem), DT (dual tandem), LCN (load classification

number), and other rating systems used throughout the world. The ACN-PCN

system applies only to pavements with bearing strengths of 12,500 pounds or

higher. For pavements having lower bearing strengths, an older system using

letters still applies in the United States.

ACN is the aircraft classification number and PCN is a corresponding pavement

classification number. An aircraft having an ACN equal to or less than the PCN

can operate without restriction on the pavement. Therefore, the PCN is the

maximum pavement bearing strength for unrestricted aircraft operations.

To correct deteriorating pavement surfaces, or increase the strength of exist-

ing runways, taxiways, or ramp areas, a pavement overlay is commonly used.

Overlays can be either hot-mix asphalt (HMA) or concrete. Before an overlay

can be applied, any existing cracks or joint faults must be sealed to mitigate

reflective cracking. Reflective cracking occurs when an underlying pavement

crack works its way through a new overlay due to different coefficients of

expansion, contraction, or movement of the two surfaces. To help delay the

Erosion caused by

water seepage is the

most detrimental factor

affecting pavement

surfaces and conse-

quent maintenance.

Pavement potholesare typically formed

when loads are

imposed over a

pavement sub base

area, weakened by

water erosion.

If pavement failure

occurs because the

airport allowed

aircraft operations that

exceeded the pave-ment limitations, the

cost to restore the

pavement to satisfac-

tory condition may

not be eligible for

federal funding.

9

ACN—aircraft

classification number

PCN—a correspond-

ing pavement classifi-

cation number, indi-

cating the maxi-mum

pavement bearing

strength for unrestric-

ted aircraft operations

Objective 6

Reflective cracking

occurs when an

underlying pavement

crack works its way

through a new overlay

due to different coeffi-

cients of expansion,

contraction, or movement

of the two surfaces.

HMA—hot-mix asphalt,

one form of pavement

overlay that is used to

correct deteriorating

pavement surfaces or

increase the strength of

existing runways,

taxiways, or ramp areas



progression of reflective cracks, pavement engineers have used different

methods such as coarse mix binder and engineering fabrics.

Until 1997, the FAA would not participate in the maintenance expense funding

of pavement surfaces. However, congressional reauthorization of airport im-

provement funding in that year provided for a pilot program to fund several

maintenance projects at selected airports in an effort to determine its cost-benefit.

The FAA design standards for pavements are based on a 20-year design life.

Asphalt pavement normally maintains good resiliency for 10 years, but

quickly deteriorates at a faster rate the second 10 years. Rehabilitating pave-

ments at the 11-15 year mark is projected to take less time and extend pave-

ment life at a lower cost than replacing the pavement at 20 years. Since 1995,

federal law has required airport management seeking funding for pavement

rehabilitation or reconstruction to have a Pavement Management System

(PMS) in place as a grant assurance condition.

The establishment of a Pavement Management System (PMS) helps to guideairport management and FAA decisions on use of federal monies for mainte-

nance. A PMS provides a consistent objective and systematic procedure for

setting priorities and schedules, allocating resources, and budgeting for pave-

ment maintenance and rehabilitation.

The regulations are specific for certificated airports regarding pavement

conditions that can affect the safety of aircraft. The regulations call for the

removal of pavement edges exceeding three inches between abutting pave-

ment and/or other areas, and cracks or holes that could impair directional

control. A hole is defined as an opening larger than five inches in diameter,

exceeding three inches in depth with an inside side slope greater than 45degrees. Any pavement crack or surface deterioration that produces loose

aggregate or other contaminants must be repaired immediately.

When inspecting pavement surfaces, airport management should be looking

for other types of surface deterioration. These include spalling, raveling, and

alligatoring; debris and/or foreign objects. These could cause aircraft or

engine damage; pavement depressions, undulations and/or bumps. Airport

management should also be observant for any pavement-edge obstruction that

could impede water runoff; the buildup of rubber deposits from aircraft tires;

the condition and/or visibility of pavement markings; the presence of erosionof soil at runway edges allowing water to seep underneath; and vegetation

growth through open or silted-in joints or cracks. Inspection of pavement

surfaces is required daily during air carrier activity.

Asphalt pavement does not necessarily wear out, but it ages through the

oxidation of the asphalt binder and by water causing it to loosen the fine

surface aggregates. A seal coat protects asphalt against the highly damaging

effects of gas, oil seepage and other pavement chemicals. Sealing asphalt

The FAA design

standards for pave-

ments—20-year design

life

Rehabilitating pave-ments at the 11-15 year

mark is projected to

take less time and

extend pavement life at

a lower cost than

replacing the pave-ment

at 20 years.

Asphalt pavement

maintains good

resiliency to ten years

but quickly deteriorates

at a faster rate thesecond ten years.

PMS—Having a

Pavement Management

System in place is a

federal requirement.

10

Spalling—fractured

edges in and around the

joint area of concrete as

a result of to the

tremendous pressures

generated during

expansion and contrac-

tion of the slabs

Pavement depressions,

undulations and/or bumps, erosion of soil

at runway edge,

vegetation growth,

etc., are all potential

runway problems.

Daily inspection of

pavement surface is

required during air

carrier activities.



helps prevent water seepage in the porous asphalt structure, slowing water

damage caused by rain, snow, frost, freezing, and thawing.

Different means exist for the testing and evaluation of pavement surfaces. A

records and site inspection are the simplest means of evaluation. The sam-

pling and testing of material provide a more accurate assessment. Direct

sampling involves the removal of core samples and subjecting them to lab

compression tests, while another sampling method uses Non Destructive

Testing (NDT) techniques which does not require material replacement or

subsequent sealing around areas removed during coring. Ground penetrating

radar and the use of infrared thermography are examples of NDT testing.

An evaluation of a complete runway using inspection, surveying, sam-

pling, and NDT techniques helps to establish a Pavement Condition

Index (PCI). PCI is a numerical rating of the surface condition of a

pavement along its entire length and width. A PCI of 100 indicates no

defects, while a PCI of zero indicates no useful pavement life exists.

The FAA conducts an annual inspection of all Part 139 airports and arranges

for the annual inspection of most other public-use airports, either through the

state aviation organizations or by themselves. The results are reported as part

of the Airport Safety Data Program, using FAA Form 5010, Airport Master

Record. Runway pavement condition is classified as good (all cracks and

joints sealed), fair (mild surface cracking, unsealed joints, and slab edge

spalling), or poor (large open cracks, surface and edge spalling, vegetation

growing through cracks and joints).

Pavement Skid-Resistance

Guidelines and standards exist for the design and construction of skid-resis-

tant pavement, for pavement evaluation with friction measuring equipment,

and for the maintenance of high skid-resistant pavements. The braking per-

formance on pavement surfaces for aircraft, especially turbojet aircraft, is

critical to safe operations. Wet pavement, snow or ice covered pavements,

and those with rubber deposits or other contaminants can result in aircraft

hydroplaning or unacceptable loss of traction. These conditions can result in

poor braking performance and possible loss of directional control. Research

into improved braking action has resulted in two major areas of attention: (1)

high skid-resistant pavement surface design and evaluation, and (2) theapplication of proper maintenance techniques and procedures.

Hydroplaning occurs (1) when tires lose contact with the pavement surface

due to contamination of some form such as water, snow, ice, or rubber and

(2) when the right combination of aircraft speed, loading, and surface condi-

tions exist. It can occur at low speeds and to small piston aircraft as well as

much larger aircraft. There are three types of hydroplaning: dynamic, vis-

cous, and rubber reversion.

NDT—Non Destruc-

tive Testing tech-

niques, such as the use

of ground penetrating

radar and infraredthermography, are

used for evaluating

pavement surfaces

PCI — Pavement

Condition Index, a

numerical rating of the

surface condition of a

pavement along its

entire length and width

11

Hydroplaning occurs

(1) when tires lose

contact with the

pavement surface due

to contamination of

some form such as

water, snow, ice, or

rubber and (2) when

the right combinationof aircraft speed,

loading, and surface

conditions exist.

Three types of

hydroplaning—

dynamic, viscous, and

rubber reversion.



Dynamic hydroplaning is a phenomenon that occurs on any surface. It gener-

ally occurs at high speed and is dependent upon aircraft load, speed, aircraft

tire pressure, and footprint area. A minimum fluid film density is also re-

quired. In dynamic hydroplaning, a wave of water builds up in front of a

rolling tire and allows the tire to ride up on a cushion of water and lose

contact with the runway surface. This results in loss of traction, steering

ability, and braking.

Viscous hydroplaning is a lubricating effect that occurs when a thin film of oil,

grease, dirt, rubber particles, or a smooth runway having water or other liquid on

the surface make the surface more slippery. Viscous hydroplaning prevents a tire

from making positive contact with the pavement and results in skidding.

Rubber reversion hydroplaning is less commonly known. It is caused by the heat

buildup beneath a tire footprint area due to friction. The heat causes the tire to

revert to its uncured state and form a seal that traps high-pressure super-heated

steam caused by the resultant friction. Rubber reversion hydroplaning occurs

primarily during landing and prevents a spin-up of the tire on touchdown.

Pavement grooving, asphalt porous friction courses, and the wire combing of

concrete surfaces have measurably improved the ability of runway surfaces to

shed water and provide for better traction. The most effective, economical

method of reducing hydroplaning is runway grooving. Pavement grooving

consists of forming or cutting closely spaced transverse grooves on the

runway surface. A porous friction course is a layer of asphalt aggregate with

voids in it that allow for better water drainage. Wire combing Portland ce-

ment just after it is poured provides a coarser texture for concrete surfaces,

which provide better friction capabilities.

The accumulation of contaminants in runway grooves reduces their water-

channeling capabilities, thereby decreasing the skid-resistance potential. In

simple terms, the water remains on the runway longer. For many airports, the

most persistent runway contaminant problem is rubber deposits from the tires of

landing jet aircraft. This requires maintenance to remove the rubber. Rubber

deposits occur primarily at the runway touchdown areas and can build up rapidly.

The removal of rubber deposits and other similar contaminants can be accom-

plished through a high-pressure water spray, the use of chemical solvents, high

velocity abrasive impact techniques, or mechanical grinding.

The effects of mechanical wear and the polishing action are directly depen-

dent upon the volume and type of aircraft traffic. Other influences on the rate

of deterioration are local weather conditions, the type of pavement; the

materials used in original construction, any subsequent surface treatment, and

airport maintenance practices. Structural pavement failure such as rutting,

raveling, cracking, joint failure, settling, or other indicators of distressed

pavement can also contribute to runway friction losses. The FAA expects

prompt repair by airport maintenance of these problems.

In dynamic hydro-

planing, a wave of

water builds up in

front of a rolling tire

and allows the tire to

ride up on a cushion

of water and lose

contact with the

runway surface. This

results in loss of

traction, steering

ability, and braking.

Runway grooving is

the most effective,

economical method of

reducing hydroplaning.

12

For many airports, the

most persistent

runway contaminant

problem is a deposit

of rubber from the

tires of landing jet

aircraft

The effects of

mechanical wear and

the polishing action

are directly dependent

upon the volume and

type of aircraft traffic.



Pavement Friction Measurement

The operator of any airport with significant jet aircraft traffic should

schedule annual friction evaluations of each runway that accommodates

jet aircraft. Depending on the volume and type (weight) of traffic on the

runways, evaluations may become more frequent and necessary.

There are two basic types of friction measuring equipment available for

conducting friction surveys on runways during winter operations—

Decelerometers (DEC) and Continuous Friction Measuring Equipment

(CFME). Decelerometers, which can be either mechanical or electrical, are used

primarily to assess friction properties of runways during winter operations. They

are not approved for conducting runway pavement maintenance surveys or for

providing consistent measurement of wet runway surfaces. The Bowmonk and

the Tapley are the most commonly used decelerometers at airports. They are

normally placed or mounted inside the inspection vehicle.

CFME devices provide a continuous graphic record of the pavement surfacefriction characteristics with friction averages for each one-third portion of a

runway length. The devices are either towed or installed in ground vehicles

capable of conducting the friction test at speeds of 40 mph or 60 mph for the full

length of the runway. (This compares to speed of 20 mph for decelerometers.)

Several CFME devices have the ability to carry water and provide self-wetting

capabilities for conducting and evaluating wet pavement conditions. Both DECs

and CFMEs are eligible for federal funding under the AIP program.

The Greek letter Mu is used to identify friction values. It is a measurement

that gives an indication of the slipperiness of a paved surface. Mu values

range from zero to 100 where zero Mu has no friction properties and 100

represents a full contact and action between a tire and the pavement. Gener-

ally, Mu readings below 60 on normal runways are considered to be below

the FAA’s maintenance planning levels and corrective action is required.

During snow and ice conditions, Mu readings below 40 are reported to pilots,

because that is when the braking action of aircraft begins to be compromised.

A friction report of Mu 27 or less means that an aircraft may experience

directional control and/or braking difficulties and the airport must apply

surface treatment to increase the friction coefficient.

Airports without CFMEs often have devices that report braking action as Good,Fair, Poor or Nil. Those readings can be conveyed, but not if a device having Mu

reading capability is available. In those cases, only the Mu value is conveyed

since no correlation exists between the two different ratings. This is because

braking action is subjective, whereas a Mu value is quantitative. What is consid-

ered a “Good” braking action for one person may be “Poor” or “Nil” to another.

Three friction measurements are taken and reported by CFMEs for each runway

(one measurement for each third of a runway’s length) in the direction of takeoff

and landing. The reporting of friction readings is found under the section on

Airport Condition Reporting.

DEC—either

mechanical or electrica

decelerometers are used

primarily to assess

friction properties of

runways during winter

operations.

CFME—Continuous

friction measuring

equipment provides a

continuous graphic

record of the pavemen

surface friction

characteristics with

friction averages for

each one-third portion

of a runway length.

13

Objective 7

Mu is a measurement

that gives an indication o

the slipperiness of a

paved surface; Mu

readings of less than 60

on normal runways are

generally considered to b

below the FAA’s

maintenance planning

levels.

Mu readings below 40

are reported to pilots,

because that is whenthe braking action of

aircraft begins to be

compromised.

Three friction mea-

surements are taken

and reported by

CFMEs for each

runway in the directio

of takeoff and landing



Movement and Safety Areas

FAR Part 139 requires management to identify those areas of the airport that are

to be used for air carrier operations. Known as aircraft movement areas (AMA),

they include runways, taxiways, and other areas of the airport that are used for

taxiing, takeoff, and landing of aircraft. They do not include loading ramps,

aircraft parking aprons, unpaved areas, or other areas that are not structurallycapable or that airport management has decided to preclude air carrier aircraft

from using. Those areas are known as non-movement areas.

A term commonly used at airports is the Air Operations Area (AOA). An

AOA, which really is a term originally identified under security regulations,

encompasses all portions of the airport designed and used for landing, taking

off, or surface maneuvering of aircraft. In that sense, AOA encompasses both

movement and non-movement areas. The AOA includes the runways, taxi-

ways, ramps, aprons, grass landing strips and parking areas, helipads or

hovering routes, and tie-down areas.

The distinction between movement and non-movement areas is necessary be-

cause not all areas of an airport available for aircraft maneuvering may be able to

meet the requirements of Part 139. Therefore, only those areas identified in the

ACM as being movement areas for air carrier aircraft are subject to the regula-

tions. Airport management is obligated to maintain to the standards and condi-

tions of the AMA as defined in an approved ACM. However, liability and practi-

cality concerns dictate that non-movement areas should not be neglected.

At airports with Air Traffic Control Towers (ATCT), the AMA generally

corresponds to those areas that are under the positive control of the ATCT.Airport and tower management sign Letters of Agreement (LOA) or Memo-

randums of Understanding (MOU) to identify those movement areas which

will be under the positive control of the ATCT, and those non-movement

areas that are the responsibility of airport management.

A safety area is a defined area comprising either a runway or a taxiway and the

surrounding surfaces, an area that is prepared or suitable for reducing the risk of

damage to airplanes in the event of an undershoot, overshoot, or excursion from

the runway or the unintentional departure from a taxiway. This safety area is

cleared, drained, and graded because it must be able to support aircraft in the

event they veer off the pavement. It must also be able to support emergency andmaintenance equipment responding to the aircraft. The safety area includes the

runway’s structural pavement, shoulders, blast pad, and stopways.

Safety areas have a total width range of 120 to 500 feet, depending on the aircraft

design group and the approach to the runway. Taxiway safety areas range from

49 to 262 feet in total width. Airport management is required to inspect daily the

safety areas for items such as rutting, rough and/or uneven terrain, mounds of

dirt, debris, and obstructions not mounted on frangible couplings. Objects lo-

Objective 8

AMA—Aircraft

Movement Areas—

include runways,

taxiways, and other areas of the airport

that are used for

taxing, takeoff, and

landing of aircraft.

AOA—Air Operations

Area— includes the

runways, taxiways,

ramps, aprons, grass

landing strips and

parking areas, helipads

or hovering routes, and

tie-down areas.

Only those areas

identified in the ACM

as being movement

areas for air carrier

aircraft are subject to

the Part 139 regula-

tions.

14

ATCT—Air Traffic

Control Towers

LOA—Letters of

Agreement

MOU—Memorandum

of Understanding.

A safety area is a

defined area compris-

ing either a runway or

a taxiway and the

surrounding surfaces,

an area that is pre-

pared or suitable for

reducing the risk of

damage to airplanes in

the event of an

undershoot, over-

shoot, or excursion

from the runway or

the unintentional

departure from a

taxiway



cated in the safety area because of their function (i. e., lights, signs) must be

mounted on frangible couplings that have breakaway points no higher than three

inches above grade.

An often-cited statistic from on-airport aircraft accidents shows that about 90

percent of the aircraft involved remain within about 1,000 feet of the runway

departure end and 250 feet from the runway centerline. For this reason, runway

safety areas have extensions past the runway ends to provide a greater safety

margin for aircraft, which undershoot or overshoot the runway. Those dimensions

vary from 250 feet at general aviation airports to 1,000 feet for airports with preci-

sion approach runways. Some airports may have less than the FAA standard

dimension since they were grandfathered when the design standards changed.

Efforts are being made to reduce the severity of airport accidents and incidents by

improving the overrun areas where the majority of these situations occur. Newer

technology or alternative systems have been developed for those airports not able

to develop the 1,000 foot overrun due to existing structures, bodies of water, large

drop-offs, railroads, or highways. One is a soft ground arrestor system. It is aporous cellular concrete bed area at the end of a runway that deforms under the

weight of a heavy aircraft, resulting in major drag and deceleration of the aircraft.

It is designed to not deform under normal ground vehicle loads.

Markings, Signs and Lighting

The FAA classifies runways in a number of ways. They can be categorized

according to their pavement surface (asphalt or concrete), intended aircraft usage

(utility, transport, heliport, STOL port, or seaplane), or by type of aircraft ap-proach. The most common is according to the type of aircraft approach used for

the runway (visual, non-precision, or precision instrument).

A visual approach runway does not require navigational aids to assist the

pilot. It is intended to be used solely under Visual Flight Rules (VFR) condi-

tions; therefore, only visual cues for landing are necessary. A non-precision

runway approach is one that uses horizontal navigational guidance to help a

pilot line the aircraft up with the runway. A precision instrument runway

approach has both vertical and horizontal navigational guidance provided by

an Instrument Landing System (ILS) or Precision Approach Radar (PAR).

Both precision and non-precision approaches require FAA approval andpublication of the procedures to use the approaches.

The published approach establishes criteria for the type of lighting and

markings to be used for the runway and associated taxiways. In the 1920s,

airfields were first lighted by the use of fire pots or regular white electrical

lights placed around the perimeter of the whole open landing field. There

were no taxiways. As aircraft weights increased in the 1930s, paved surfaces

transformed the normally open grass or dirt landing area into very distin-

Safety Areas have a

total width range of

120 to 500 feet;

taxiway safety areas

range from 49 to 262

feet in total width.

The safety areas at

certificated airports

extend past the runway

end by 1,000 feet

15

The most common

runway classification is

by the type of aircraft

approach — visual, non-

precision, or precision

instrument.

A non-precision

runway approach is

one that uses horizon-tal navigational

guidance to help a

pilot line the aircraft

up with the runway,

whereas a precision

instrument runway

approach has both

vertical and horizontal

navigational guidance

provided by an

Instrument Landing

System (ILS) or

Precision ApproachRadar (PAR).

VFR—Visual Flight

Rules

ILS—Instrument

Landing System

PAR—Precision

Approach Radar



guishable landing surfaces. The perimeter lighting then outlined the paved or

graded surface rather than the whole landing area.

Since those early days, the lighting and marking of runways and taxiways have

evolved, to increase the level of safety through standardization and uniformity.

This ensures pilot understanding. Airport management’s job is to maintain the

standards and uniformity through routine inspection and maintenance.

Airfield Lighting

Runway lighting systems are classified according to their intensity or brightness.

Depending on the type of approach, the systems will have High Intensity (HIRL),

Medium Intensity (MIRL), or Low Intensity Runway Lights (LIRL). The HIRL

and MIRL systems have different intensity levels or “steps,” whereas the LIRL

systems normally have one intensity setting or step. Intensity settings can be 1, 3,

5 or 7 steps, depending on the visibility conditions.

Many airports, not staffed 24-hours, have pilot-controlled lighting systemsinstalled. Keying the aircraft radio’s microphone switch several times in rapid

succession on a predetermined and published frequency activates these systems.

They provide a greater degree of pilot safety and reduce the airport’s operating

and maintenance costs.

In the ACM, clear instructions are required on how many and in what sequence

lights may be out before a system is considered inoperative. If more than three

lights in a row or more than 10 percent of a runway or taxiway route system are

inoperative, then standards are not being met. Snow, ice, or other conditions

obscuring the lights or causing outages may also make the system inoperative. A

Notice to Airmen (NOTAM) is required if standards are not met. The ACM is to

have detailed information on the lighting systems in place at the airport.

Runway edge lights are white. On instrument runways, amber lights replace

the white ones in the direction of landing for the last 2,000 feet or for one-half

the runway length, whichever is less. This provides visual safety information to

a pilot as he or she approaches the end of the runway. Taxiway edge lights have

solid blue lenses.

Threshold lights which mark the ends of the runway are of the colored split lens

type. The lens indicating the end of a runway to a departing aircraft is red whilethe other lens, which indicates the start of the runway for landing aircraft, is

green. Runway lights are directional in their focus through what is known as a

Fresnel lens. This lens requires the light bases to be properly aligned with the

runway and angled toward the landing approach.

In addition to the runway lights, several other lights can be found associated with

runways, depending on the approach. Precision runways can have Touchdown

Zone Lighting (TDZL), Runway Centerline Lighting (RCLS), and taxiway

Objective 9

Depending on the type

of approach, the

intensity of runway

lighting system ranges

from high to low.

16

NOTAM—Notice to

Airmen

If more than three

lights in a row or

more than 10 percent

of a runway or

taxiway route system

are inoperative, a

NOTAM is required.

Taxiway edge lights

have solid blue lenses.

Runway edge lights

are white.

Amber lights replace

the white ones in the

direction of landing

for the last 2,000 feet

or for one-half the

runway length,

whichever is less.

Runway lights are

directional in their

focus through what is

known as a Fresnel

lens.

Lights marking the end

of a runway to a

departing aircraft—red

Lights marking the

start of a runway to a

landing aircraft—green



turnoff lighting. TDZL are in-pavement lights on both sides of the runway

centerline starting at 100 feet past the threshold and extending up to 3,000 feet

down the runway. RCLS are in-pavement lights on the centerline of the runway.

White in color for the majority of the runway, the white lens is alternated with

red starting 3,000 feet from the end of the runway. With 1,000 feet remaining,

they all become red.

Taxiway turnoff lights are in-pavement green lights that lead from the runway

centerline onto a taxiway or vice versa. Some airports have the green taxiway

center lights mark the complete route between the terminal and the active runway.

At U. S. airports having the capability of allowing air carriers to conduct opera-

tions when the visibility is less than 1,200 feet Runway Visual Range (RVR),

Surface Movement Guidance and Control Systems (SMGCS) are being imple-

mented. SMGCS is a system of guidance, control, and regulation of all aircraft,

ground vehicles, and personnel on the movement areas during low visibility

conditions. The intent of the SMGCS is to prevent collisions and ensure that

traffic flows smoothly and freely in low visibility conditions. Guidance andregulation of aircraft are accomplished through surface markings, stop-bar

lights, clearance-bar lights, hold-position lights, training, and installation of

advanced technologies such as Forward Looking Infrared (FLIR) systems,

Enhanced Vision Systems (EVS), Head Up Displays (HUD), and Global Posi-

tioning Systems (GPS).

Another light of importance to an airport is the rotating beacon. Rotating beacons

help to identify the airport location and area to a pilot. The light emitted from a

beacon is angled from two to ten degrees above the horizon, depending on the

surrounding terrain. Civil land airports have a white-green beacon.

As a safety measure, beacons are designed and built so that if one bulb burns out,

a backup bulb will activate. The system also provides information by a secondary

light or signal that indicates a bulb has burned out. If a beacon is activated during the

day, it represents conditions below those for flight under visual flight rules. It could

be that the ceiling is below 1,000 feet and/or the visibility is less than three miles.

Any changes to the lighting systems of a public-use airport, including pilot-controlled

lighting, require revision in the Airport Facilities/Directory (AF/D).

Airfield Signs

Airfield signs provide useful information to ground vehicle operators when driving

on the airport and to pilots during takeoff, landing, or taxiing. Airfield signs,

normally located on the left handside in the direction of travel (except for runway

exit signs), are intended to provide easy determination of where a pilot or ground

operator is, where he or she needs to go, and/or where he or she needs to stop until

further clearance is given. Signs and markings also identify boundaries of ap-

proach areas, ILS critical areas, runway safety areas, and/or obstacle free zones.

Taxiway turnoff lights

are in-pavement green

lights that lead from

the runway centerline

onto a taxiway or vice

versa

SMGCS—Surface

Movement Guidance

and Control Systems—

is a system of guid-

ance, control, and

regulation of all

aircraft, ground

vehicles, and personne

on the movement areas

during low visibility

conditions.

GPS—Global Posi-

tioning Systems

17

TDZL—Touch-Down

Zone Lighting

RCLS—Runway

Centerline Lighting

A rotating beacon

should be activated

when conditions exist

at an airport below

those established for flight under visual

flight rules.

Changes to the lighting

systems of a public-use

airport require revision

in the Airport Facilities

/Directory (AF/D).

Objective 10

Mandatory signs—

have white inscriptions

on a red background

and require an indi-

vidual at a controlled

airport to obtain

clearance before

proceeding



Mandatory signs have white inscriptions on a red background and require an

individual at a controlled airport to obtain clearance before proceeding, or at an

uncontrolled airport to continue only with appropriate precautions. Mandatory

signs are used only in conjunction with runways with the exception of the no

entry sign. Location signs identify the taxiway or runway upon which the aircraft

or vehicle is located. They have yellow inscriptions on a black background. A

different type of location sign has black inscriptions on a yellow background;

these signs identify the boundary of the Runway Safety Area (RSA), Obstacle

Free Zone (OFZ), and ILS critical areas. The RSA, OFZ, and ILS signs are

installed only at airports with operating control towers and where pilots or

vehicles are often asked to report clear of a runway or critical area.

Directional signs provide information on the location and orientation of other

taxiways from the one where the pilot or ground operator is. They always

contain an arrow. Black inscriptions on a yellow background identify taxiways

leaving a runway or the direction of taxi routes. Where a taxiway ends, a taxi-

way-ending marker is normally installed. Destination signs are similar to direc-

tion signs except that they point toward a general location on the airport ratherthan a specific route. Sample destination signs are: APRON, FUEL, TERM(inal

area), CIVIL (aircraft area), MIL(itary area), PAX (passenger handling),

CARGO, INTL (international area), and FBO (fixed base operator).

A dot (%) between the inscriptions on a destination sign is read to mean “and”

while a hyphen (-) is used only on mandatory signs. A solid black vertical line

separates adjacent directional or destination insignia. Special informational signs

such as noise abatement procedures are black inscriptions on a yellow back-

ground. On runways, distance-remaining signs are placed along the runway at

Location signs—(1)

those with yellow

inscriptions on a black

background are used

for identifying the

taxiway or runway

where the aircraft or

vehicle is located (2)those with black

inscriptions on a

yellow background are

used for identifying the

boundary of the

Runway Safety Area,

Obstacle Free Zone,

and ILS critical areas.

Black inscriptions on a

yellow background

identify taxiways

leaving a runway or thedirection of taxi routes.

Taxiway directional

signs—with an arrow

and black inscription

against a yellow

background

Figure 1: Signing Examples for a Complex Airport

18

Destination signs—

similar to directional

signs but point toward

a general location on

the airport rather thana specific route, e.g.,

APRON, FUEL,

TERM (inal area),

CIVIL (aircraft area),

MIL(itary area), PAX

(passenger handling),

CARGO, INTL

(international area),

and FBO (fixed base

operator). A dot (%)

between inscriptions

mean “and.”

Special informational

signs have black

inscriptions on a

yellow background,

e.g., noise abatement

procedures.



intervals of 1,000 feet. Located 20 to 75 feet from the pavement edge, depending

on the size of the sign, they have single white numbers on a black background.

Where signs cannot be installed and/or where there is a need for additional

information, directional guidance or location can be painted on the pavement.

Airfield Markings

Similar to signs, pavement markings provide information that is useful to both

pilots and ground vehicle operators. They can be grouped into four categories:

runway, taxiway, holding position, and others. Markings for runways are white,

as are helicopter-landing areas with the exception of hospital helicopter pads,

which are red. Taxiway centerlines, closed and hazardous areas, and holding

position indicators are yellow, even though they may be located on a runway.

Similar to pavement lighting, runway markings are determined by the type of

approach to the runway. Those common to all runways include centerlines,

designator, and holding indications. A non-precision instrument runway will

include threshold and aiming point markers. Those for a precision instrument

runway include all the previous plus touchdown zone and side stripes markings.

Visual runways, 4000 feet and longer, used by jet aircraft require aiming-points.

Located 1,000 feet past the approach end of the runway, aiming-points spot

where a jet on a normal glidepath will touch down. Touchdown zone markingsare spaced at 500 feet intervals and provide distance information according to

the number of rectangular bars.

Runway threshold bars are a number of longitudinal lines (usually eight but as

many as sixteen depending on runway width) that identify the beginning of a

runway. Visual approach runways do not have threshold markings. In the event

of construction, maintenance, or other activity causing a partial runway closure,

the threshold is relocated and airport management is required to file a NOTAM

Distance-remaining

signs are placed along

the runway at intervals

of 1,000 feet. These

signs have single white

numbers on a black

background.

Four categories of

pavement markings—

runway, taxiway,

holding-position, and

others

Runway markings

and helicopter-landing

areas — white, except

for hospital helicopter

pads, which are red

Taxiway centerlines

are yellow.

Table B: Runway Marking Elements (Source: FAA).

Visual Non-precision Precision

Marking Element Runway Instrument Runway Instrument Runway

Designation x x x

Centerline x x x

Threshold x1 x x

Aiming points x2 x x

Touchdown Zone x x x

Side Stripes x x x

1 On runways used or intended to be used, by international commercial transport

2 On runways 4,000 feet or longer used by jet aircraft

19

Visual runways, 4000

feet and longer, used

by jet aircraft require

aiming-points.

Touchdown zone

markers—Spaced at

500 feet intervals,

these markers providedistance information

according to the

number of rectangular

bars.

Runway threshold

bars — from eight to

sixteen longitudinal

lines that identify the

beginning of a runway



and possibly remark the runway depending upon the duration of the activity. A

solid 10-foot wide white bar across the runway would identify a threshold that

has been relocated.

When it is necessary to site a threshold other than at the runway end, a displaced

threshold is used. This relocation is primarily needed because of an obstruction

in the runway approach. It is a white bar 10 feet in width across the runway.

A demarcation bar is a different type of marking across the runway. It distin-

guishes a displaced threshold from a stopway, blast pad, or taxiway that pre-

cedes the runway. The bar is three feet wide and painted yellow. Leading up to

the demarcation bar is a series of yellow chevrons indicating an unusable area

for landing, takeoff, or taxiing. Arrows and arrowheads help to identify andlocate a displaced threshold. If the arrows are used in a displaced threshold, they

are white in color.

Figure 2: Runway Markings

Figure 3: Special Runway Markings

20

Displaced threshold —

a 10-feet wide bar

placed across the

runway when there is

an obstruction in the

runway’s approach.

Demarcation bar — 3-

feet wide yellow bar used to distinguish a

displaced threshold

from a stopway, a blast

pad, or a taxiway that

precedes the runway



Other types of markings exist for the runways and taxiways. Shoulder stripe

markings are used on both runways and taxiways to identify non-structural

adjacent pavement. Sidestripes are used on runways and taxiways to provide a

visual contrast between the usable surface boundaries. They are one continuous,

solid white line on runways and two parallel continuous yellow lines on taxi-

ways. An exception is where a taxilane is defined on an apron area. Instead of

two solid lines, the markings consist of broken lines.

Taxiways at public-use airports are required to have taxiway centerlines and

runway hold-position markings. A taxiway centerline is a single continuous

yellow line, even where it extends onto the runway (called lead on/off lines).

Taxiway hold-position bars are four yellow parallel lines—two dashed lines and

two solid ones. The two dashed lines are closest to the runway. Aircraft or

vehicles approaching the runway will encounter the two double solid lines,

which require authorization from the ATCT to cross if a control tower is in

operation at the airport. Yellow in-pavement lights help to further distinguish the

hold-position marking.

At non-controlled airports, extreme diligence is used when approaching a hold-

position line. Safe practices would have the pilot or vehicle operator announce

over the radio his or her entry onto the runway before crossing the hold lines.

Upon exiting the runway, the pilot encounters the double dashed lines first, and

once passing both the dashed and solid lines, the pilot would announce being

clear of the runway.

Some airports have critical areas associated with navigational equipment. An

aircraft, piece of equipment, or vehicle in the critical areas can disrupt the

navigational signal. To keep aircraft and vehicles clear during IFR conditions, a

yellow ladder-type marking is used.

Airports with VOR facilities may have VOR ground checkpoint markings and

signage installed. The checkpoints allow pilots to calibrate aircraft instruments

on the ground. The checkpoint marking is a circle with an arrow directed toward

the navigational aid and is located within one-half mile of the VOR. The mark-

ing is two concentric circles—the outside white and the inside yellow—with a

yellow arrow. It is supplemented by a sign identifying the checkpoint and giving

the VOR identification letters and the course radial. If available, DME informa-

tion is also listed. The signage letters are black on a yellow background.

Closed runways and taxiways are marked by yellow X’s placed to obscure each

runway number, or are placed at the beginning and end of a taxiway. New

technology has resulted in raised lighted X’s as a substitute. Permanently closed

runways or taxiways additionally require disconnecting lighting circuits and

obliterating pavement markings. The marking of construction areas requires

special attention in the construction safety plan to ensure visibility and meaning.

Sidestripe markings —

one continuous solid

white line on runways

and two parallel

continuous yellow

lines on taxiways,

used to provide visual

contrast between the

boundaries of the

usable surface

Taxiways at public-

use airports are

required to have

taxiway centerlines

and runway hold-

position markings.

A taxiway centerline

is a single continuous

yellow line, even

where it extends onto

the runway.

Taxiway hold-position

bars—four yellow

parallel lines, two

broken and two solid.

Solid are on the

taxiway side and

broken are on the

runway side.

21

Checkpoint mark-

ing—a circle with an

arrow directed toward

the navigational aid,

located within one-

half mile of the VOR

Markings for closed

runways and taxi-

ways—yellow X’scovering up each

runway number or at

the beginning and end

of a taxiway



At airports having authorized Land and Hold Short Operations (LAHSO) for

two intersecting runways, or where the runway is used as a taxiway to another

runway, a yellow double solid and double dash hold-position marking extends

across the runway to identify the hold-short position. It is supplemented with

white on red signs adjacent to the runway. In-pavement lights help to distinguish

the hold-position line on Category II and III ILS runways. For airports required

to have a SMGCS, the stop-bar lights would be red.

One component of a SMGCS is painted taxiway markings that complement the

lighted guidance and informational signs. A SMGCS also requires elevated or

in-pavement runway guard lights, green centerline, and lead-on lights for pre-

ferred taxi routes, taxiway lights, clearance bar lights, gate-designator markings,

geographic hold-position markings (“ spots”), and yellow elevated runway guard

lights at hold positions (“ wig-wags”) along with in-pavement lights.

Vehicle roadway markings are intended to reduce the risk of an aircraft and

vehicle accident on the AMA or AOA. Driving lanes are normally like those on

highways, solid white boundary lines with a white broken centerline. An alter-native is to use white “zippered” (required for SMGCS) markings. Outside of

the AOA, markings should conform to those in the Department of

Transportation’s Manual on Uniform Traffic Control Devices.

For pavement markings two choices of paint exist: water-based (latex) or oil

based. Similar to the application of pavement sealers, pavement paint has less

friction than the asphalt or concrete it covers. The addition of silica sand or glass

bead can provide added texture to improve the friction properties of the painted

surface. Glass beads, which reflect light, are required to be added to the paint to

make the markings more conspicuous.

Two other types of markings/piloting aids can be found at airports: a compass

rose and a segmented circle. A compass rose is a painted or other marking that

is located on a surface large enough for aircraft to maneuver and be aligned to

the different magnetic headings marked on the pavement. The compass rose is

used to help calibrate aircraft magnetic compasses.

The segmented circle marking is actually a series of objects on the ground

designed to give traffic pattern and wind information to pilots in the air. A

segmented circle is a series of highly visible white or yellow markers arranged

in a circle to help a pilot identify important landing pattern and wind directioninformation. A segmented circle is required for airports serving any air carrier

operation and when there is no control tower in operation.

Inside the segmented circle is a wind indicator. Wind indicators pivot in the

wind and can be a tetrahedron, a wind cone (windsock), or a combination of

both. A landing strip indicator extends from the segmented circle for each

runway. If a right-hand traffic pattern exists, a traffic pattern indicator extends

from the landing strip indicator.

LAHSO—Land and

Hold Short Operations

22

A compass rose

marking is used to

help calibrate aircraft

magnetic compasses.

Segmental circle

marking—a series of

highly visible white

or yellow markersarranged in a circle,

with a wind indicator

inside, to help pilot

identify important

landing pattern and

wind direction

information



Depending on the model, wind cones (socks) at airports have a minimum open-

ing diameter of 18 inches, which provides an indication of wind speeds from 5

to 50 miles per hour. The cones have a distinguishing color of white, yellow, or

orange. The support structure should be orange in color.

Additional wind cones are required at airports certificated under Part 139 for each

runway available for air carrier use. These supplemental wind cones are installed at

the end of each runway, or at least at a point visible to the pilot while on final ap-

proach and prior to takeoff. For those airports open for air carrier operations during

hours of darkness, all wind direction indicators require lighting.

Snow and Ice Control

Airport managers have a duty to ensure the safety of operations at their facili-

ties. Part 139 requires a snow and ice removal plan that is current and complete,

to meet local conditions. Snow, ice, slush, and standing water degrade the

coefficient of friction; reduce braking and directional control; and impede

aircraft acceleration. Acceptable limits vary by aircraft, but most jet aircraftflight manuals limit their particular aircraft to landing with no more than one

inch of slush or standing water on the runway, and to taking off with no more

than one half inch accumulation.

The requirement for airport operators, therefore, is to remove as expeditiously as

possible all snow, ice, and slush so as to maintain runways, high-speed turnoffs,

and taxiways in a “no worse than wet” condition. Although snow is an important

and serious problem in airport maintenance operations, ice is the most difficult

problem to cope with and presents the greatest hazards to aircraft operations. A

NOTAM is issued whenever contaminants exist on the runway.

The snow and ice control plan required in an ACM includes instructions and

procedures for the following:

1. The prompt removal or control of snow, ice, and slush on each AMA.

2. The positioning of snow off AMA surfaces so that all air carrier aircraft propellers,

engine pods, rotors, and wingtips will clear any snowdrift or snow bank.

3. The selection and application of approved materials for snow and ice control.

4. The timely commencement of snow and ice control operations.

5. The prompt notification to all air carriers using the airport when there is less

than a satisfactorily cleared AMA for the safe operation of aircraft.

Since snow and ice conditions are considered an emergency situation, the timely

removal or treatment of either is important. A snow plan identifies and classifies

priority areas according to operational needs. Priority 1 areas generally are

ARFF access routes to the primary runway in use, the primary runway and its

associated taxiway routes to and from the terminal, and emergency service roads

into the airport if ARFF services are located off the airport. Clearance times are

based on the ability of the maintenance staff and the capability of equipment to

clear pavement surfaces.

Objective 10

Most jet aircraft flight

manuals limit their

particular aircraft to

landing with no more

than one inch of slushor standing water on

the runway, and to

taking off with no

more than one half

inch accumulation.

23

Ice is the most

difficult problem to

cope with and

presents the greatest

hazards to aircraft

operations.

Objective 11

Snow is first removed

from the primary

runway in use and its

associated taxiway

routes to and from the

terminal, ARFF

access routes and

emergency service

roads into the airport

if ARFF services are

located off the airport.



Snow and Ice Plan

Every fully certificated airport located where snow or ice regularly occurs is

required to have a written plan stating the procedures, equipment, and materials

to be used by the airport in removing snow and ice. Elements included in the

plan are: preseason preparation, snow committee composition, snow desk or

snow control center location, equipment, personnel training, weather reports,field condition reports, clearance criteria, clearance priorities, supervision, and

communications. A snow plan needs to be flexible enough to allow snow and ice

removal operations to change with weather and operational conditions.

Airports that are required to have a snow plan should have a snow committee as

part of the plan. The committee should be composed of representatives of

airport management, the airline flight operations department, fixed-base opera-

tors, the ATCT, the flight service station, Airway Facilities (AF), the National

Weather Service, other meteorological services, and/or other interested or

concerned parties. Air carriers normally provide information on aircraft opera-

tional limitations and assist in evaluating pavement surface conditions. Airportsin frequent or heavy snowfall areas have a “Snow Desk” or “Snow Control

Center,” which is a special operation for coordinating all snow and ice control

activities.

All snow removal vehicles operating on runways and taxiways must be in radio

communication or under the control of a radio equipped vehicle. The snow

control center facilitates communication between the ATC tower, snow and ice

control equipment and/or supervisors’ vehicles, and other support elements.

The snow control centers are to inform air carriers and the ATC of expectedrunway opening and closing times, and to serve as a prime source of field

condition information. They also ensure a timely response to a snow or ice

removal event by obtaining and monitoring accurate information about an

approaching storm and its likely effect on airport surfaces. The snow or ice

removal task can be reduced and costs lessened by a prompt, effective response

to a storm warning.

Proper application of approved chemicals on the pavement before or during the

very early stages of a snowfall will reduce the likelihood of compacted snow

bonding to the pavement. Prompt treatment will also reduce the effort needed

for either mechanical or chemical means of removing the snow. Freezing rainwill bond to a cold pavement surface and requires special treatment, depending

on the pavement surface temperature. If the pavement surface temperature is

below freezing, chemical application may be the most effective control measure.

If the pavement surface temperature is above freezing and a frozen rain (slush)

develops, brooming is a more effective method of control.

To help determine the best timing for de-/anti-ice application or snow removal,

the use of friction measuring equipment can be beneficial, or instruments that

Objective 12

Basic components of a

snow and ice plan—

(1) preseason

preparation,

(2) snow committeecomposition,

(3) snow desk or

snow control center

location,

(4) equipment,

(5) personnel training,

(6) weather reports,

(7) field condition

reports,

(8) clearance criteria,

(9) clearance priorities,

(10) supervision, and

(11) communications.

24



detect pavement conditions can be installed. Pavement condition sensing instru-

ments are sensors, which are embedded in the pavement to measure surface

conditions. They serve three functions: (1) they provide a precise measure of the

pavement temperature; (2) they indicate the presence of water, ice, or other

contaminants; and (3) they transmit this information to the snow control center

for incorporation into the decision-making process for the most appropriate

snow and ice control strategy. Both friction measuring equipment and surface

sensing instruments are eligible for funding under AIP.

Many factors influence a pavement’s temperature. Factors such as surface color

and composition, wind, humidity, solar radiation, traffic, and the presence of

residual deicing chemicals or other contaminants all need to be taken into

consideration. Since pavement temperature lags behind air temperature, use of

air temperature to infer the condition of the pavement surface is imprecise and

can be misleading. Ice will not form unless the pavement temperature reaches

the freezing point; therefore, knowledge of the direction and rate of change of

pavement temperature can provide a predictive capability for the formation of

ice. This is the benefit of a pavement sensor system.

De-ice and Anti-ice Compounds

The formation of frozen precipitation on an airport’s paved surfaces and on

aircraft is a serious concern. Snow and ice can degrade an aircraft’s performance

to the point where (1) surface maneuvering is impeded, (2) the generation of

speed or lift is diminished for takeoff, or (3) braking action and stopping dis-

tance become marginal when landing. For the air carriers, the FAA prohibits

takeoff when snow, ice, or frost is adhering to wings, propellers, control sur-

faces, engine outlets, or other critical surfaces on the aircraft.

For airport pavements, different types of chemicals or liquids may be used for

preventing or removing snow and ice accumulations. Chemicals that are avail-

able for use are: urea, acetate-based compounds, and sodium formate. Urea is a

solid synthesized crystalline granular compound that is often used as fertilizer. It

works for temperatures down to about 15 degrees Fahrenheit. Acetate-based

compounds are potassium acetate (Cryotech), calcium magnesium acetate

(CMA), or sodium acetate (Clearway 2). Another compound, sodium formate, is

marketed under the Safeway SF name. Potassium acetate can work down to -50

degrees Fahrenheit depending upon the dilution strength.

Polypropylene glycol and ethylene glycol are the two liquids approved for use

as deicing existing buildups or for the prevention of ice formation (anti-ice). De-

icing chemicals and liquids work by lowering the freezing point of the water or

liquid mixture. Anti-ice chemicals or fluids are applied prior to ice formation to

prevent bonding of the ice to the pavement. Application rates of de-/anti-icing

fluids vary depending on ice and snow accumulations and overall weather

conditions. The chemical costs to deice a runway and taxiway can become very

expensive.

25

Objective 13

Both friction measur-

ing equipment and

surface sensing

instruments are eligible

for funding under AIP.

Objective 14

Chemicals available

for deicing and snow

removal—urea,

acetate-based com-

pound, and sodium

formate

Liquids approved for

deicing—polypropy-

lene glycol and

ethylene glycol



In applying de-icing compounds, whether on pavement or on aircraft, the ratio

of water and glycol mixture is dependent upon the eutectic point desired. The

lowest temperature that a chemical melts ice occurs with a specified amount of

chemical mixture. That temperature is called the eutectic temperature, and the

amount of chemical is called the eutectic composition. Combined, they are

called the eutectic point. Ice will form on a pavement or aircraft surface in one

of four methods: (1) radiation cooling, (2) freezing of cold rain, (3) freeze-thaw

of compacted snow, or (4) freezing of ponded or melted water. All anti-icing and

de-icing compounds are dispensed on the basis of the pavement temperature or

the temperature of the aircraft skin, not air temperature.

Compared with liquid de-icers, solids can be spread simultaneously with sand

and require less equipment and fewer operators to spread. Liquid de-icers

generally require special tanks and pumping stations. Chemical snow and ice

control is expensive and affects the environment. Urea and potassium acetate do

different things to the environment.

As urea degrades, it turns into ammonia nitrate, which has high biochemicaloxygen demand (BOD) and toxicity. Both properties are detrimental to the

environment. The benefits of liquids are for lower BOD and toxicity. Among the

acetates used on runways, ammonia acetate has the greatest toxicity effect. A

drawback to using liquid, however, is that it adds bulk to snow and slush,

thereby allowing greater potential for windrow dams to be formed. Also, using

liquid deicers is more expensive than using solid de-icers. Because each

airport’s snow and ice conditions will vary, sometimes a combination of the two

methods is most effective. Safety should always come first when considering the

application of anti-/de-ice material. The airport operator should work closely

with the state’s environmental departments to ensure the legality and effects any

chemical used will have on the environment.

Aircraft De-icing

Because aircraft cannot take off when snow, ice, or frost is adhering to the

wings, propellers, control surfaces, engine outlets, or other critical surfaces, the

aircraft must be de-iced. Aircraft de-icing is accomplished by spraying one of

several types of heated aqueous solutions (water/glycol) onto critical aircraft

surfaces. The heat of the solution and the force of the spray melt and remove the

ice/snow/frost, and the antifreeze properties of the solution prevent refreezing.

The spent solution falls to the ground and follows whatever natural drainagecourse exists.

The two most common types of aircraft anti-/de-icing fluids are distinguished by

their thickness or viscosity. The first solution, known simply as Type I, is a

mixture of glycol and water that is heated to 180 degrees F. Applied to clean

frozen precipitation on the aircraft, Type I fluid protects aircraft from snowfall

for approximately 15 minutes, but it provides only 3 to 5 minutes of holdover

protection from freezing rain. Type I is orange in color.

BOD—biochemicaloxygen demand

Using liquid deic-

ers—more expensive

than using chemical

deicers

26

The eutectic tempera-

ture—the lowest

temperature that a

chemical melts ice

The eutectic composi-

tion—the amount of

chemical mixture thatmelts ice at the

eutectic temperature

Anti/de-icing fluids

are distinguished by

their thickness or viscosity.

Type I fluid—a

mixture of glycol and

water heated to 180

degrees F; protects

aircraft from snowfall

for about 15 minutes

and from freezing rain

for 3 to 5 minutes



Type IV fluid is a thicker water and glycol mixture that uses a polymer as a

thickening agent and is green in color. It does not need to be heated before it is

applied. Considered an anti-icing solution, Type IV fluid is used mostly during

heavy snowfall. Once it is applied, the fluid adheres to the aircraft’s outer

surface and does not run off until take off. However, if ice or snow has formed

on the aircraft, it must be cleaned off first using Type I fluid. Type IV fluid

holdover times can protect aircraft from heavy snowfall for up to 45 minutes.

Airport operations personnel should be familiar with the types of chemicals used

on their airport, the correct response to spills, cleanup requirements and the

proper techniques for handling such chemicals.

The use of Type I and IV fluids is expedient and efficient, though the cost of the

solutions has made it expensive and there are environmental concerns associated

with them. Neither ethylene glycol nor propylene glycol is particularly toxic,

though the EPA lists ethylene glycol as a hazardous substance. A greater con-

cern exists for the environmental effects of de-icing. Each glycol compound is

known for its biochemical oxygen demand (BOD) and for aquatic toxicity. Of

the glycols, Type IV has higher toxicity and BOD.

Air carriers and airports have a leading role and joint responsibility in the glycol

mitigation process. The carriers must produce and update a plan of operations

that is acceptable to the airport operator and the environmental agencies. To help

minimize the effects of aircraft deicing on the environment, airports are encour-

aged and even required to construct separate de-icing facilities or to acquire

equipment that can collect the fluid on the ground.

Airport management can construct, within FAA standards, either centralized or

remote aircraft de-icing facilities. De-icing facilities at terminals or on apron areas

are considered centralized. Those located on taxiways or near departure runways areconsidered remote. Siting remote facilities near departure runways minimizes the

taxiing time between treatment and takeoff. Such facilities also compensate for

changing weather conditions when icing conditions or blowing snow is expected to

occur along the taxi route taken by aircraft to the departure runway.

The primary factor for siting deicing facilities is aircraft taxi time. Beginning

with the start of the last de-/anti-icing treatment and ending with a takeoff

clearance, the taxi time must be within the holdover time of the fluid in order to

remain effective.

The acquisition or use of vehicles that vacuum or otherwise collect glycol is

another technique for mitigating the effects of glycol runoff. Many airports use

this method because it is an economical approach to the problem of glycol

recovery. The collected glycol is then stored or otherwise deposited into a

facility that will recycle or process the glycol.

Another system for de-icing aircraft has been developed. Installed in a large

open-ended hangar, this system contains infrared sources suspended from the

Type IV fluid—a

thicker water and

glycol mixture that (1)

uses a polymer as a

thickening agent, (2)

does not need to be

heated before it is

applied, and (3) has

higher toxicity and

BOD

27

Siting remote

facilities near departure runways

minimizes the taxiing

time between

treatment and takeoff

Acquiring or using

vehicles that vacuum

or collect glycol

mitigates the effects

of glycol runoff.



ceiling to melt ice and snow from the surfaces of aircraft towed through it. The

technology continues to be tested.

Snow Removal Equipment

Snow removal equipment requirements are based on the annual operations at an

airport and the amount of Priority 1 surface area to be cleared in a specified timeperiod. Commercial service airports that provide scheduled air carrier service

and experience snow conditions as presented in AC 150/5200-30A should have

sufficient snow and ice control equipment, chemicals, and personnel to meet the

removal standards established in the ACM.

Snow and ice can be removed in one of two ways, either mechanically or chemi-

cally. The four mechanical methods of snow removal include rotary blowers or

throwers, plows, broom sweepers, and loaders. The chemical methods include

material spreaders that disperse de-/anti-ice granules or liquid.

Rotary Snowblowers

The rotary snow blower or thrower is the primary mechanical device for removal

of hazardous snow accumulations such as windrows and snow banks. Rotary

snowblowers are used primarily to cast heavy concentrations of snow away from

airport operational areas such as the runways and taxiways. The equipment can

be self-propelled or attached to a carrier vehicle and uses either one or more

rotating elements (single or two-stage units) to break up and discharge the snow.

The term carrier vehicle represents the various self-propelled prime movers

(combination truck chassis, body, and engine) that provide the power necessary

to move snow and ice control equipment during winter operations.

Single-stage rotary plows use one rotating device to accomplish both the

breakup and the casting of snow. Two-stage rotary plows break up the snow in

one step and discharge in the second. Impellers, which cut and gather the snow,

can be of blade, auger, or ribbon type. Impellers, which cast the snow, can be of

a web or disk design. There are various types of snowblowers available. Their

different snow removal capacities are based on their speed and casting distance.

Snow Plows

Displacement plows consist of a cutting edge to shear snow from the pavement

and a moldboard to lift and cast the dislodged snow to the side of the cleared

path. The cutting edge may ride in contact with the pavement or be held a small

distance above it by means of shoes or caster wheels. Displacement plow sizes

are classified as follows: small (6-10 feet), intermediate (10-15 feet), large (15-

22 feet), and extra large (greater than 22 feet).

The plows themselves can be further classified as to their function and purpose.

Typical plows are: one-way fixed angle, power reversible, rollover power reversible,

Snow removal

equipment require-ments are based on the

annual operations at

an airport and the

amount of Priority 1

surface area to be

cleared in a specified

time period.

The four mechanical

methods of snow

removal include rotary

blowers or throwers,

plows, broom sweep-ers, and loaders.

28



power reversible with folding wings, flexible reversible, ramp dozer, expressway,

and vee type. Plows are most commonly mounted on the front of a carrier vehicle,

but they may also be mounted on the side or underneath the vehicle.

A ramp dozer is used primarily in confined areas that require wide to extra-wide

swath plowing, but it may also be used to transport and dump snow. A ramp

blade can be equipped with side plates to contain snow and prevent spillage.

An expressway plow provides the speed characteristics of a rigid plow and the

cleanup ability of a reversible plow. The plow has bulldozing capabilities and, if

horizontally adjusted, has the ability to cast snow to the right or left. Vee-type

plows can tackle high drifts and heavy snow. Side-mounted extension wings

increase the swath of the front-mounted plow. Leveling wings are used for

windrow and snow bank leveling/trimming operations. Underbody mounted

scraper blades provide constant ground pressure on the pavement surface.

Combined with serrated cutting edges, they are especially useful in scarifying

ice which helps to retain applications of deice chemicals or liquids.

Sweepers

Snow sweepers or brooms are used primarily to clean up the residues left on the

pavement surface by a plow or blower, or in sweeping and cleaning debris from

airport operational areas. They incorporate high-speed brooms that consist of a

number of brush sections, which may be front-mounted to a carrier vehicle

(attached or integral), underbody-mounted, or mounted on a trailer towed by a

carrier vehicle. All are capable of sweeping wet, slushy snow as well as fine dry

snow from pavement surfaces. A sweeper can be complemented by an airblast

system, which is located behind the brush assembly. A sweeper airblast system

is used to sweep the pavement area clean of snow, slush, sand, and other debris;

help dry the pavement surface, and clear snow from around runway lights.

Four different types of sweepers are used on airports: (1) pushed, (2) towed, (3)

underbody, and (4) band sweepers. The pushed sweeper precedes the carrier

vehicle while the towed sweeper is fixed to a trailer and is towed by a conven-

tional carrier vehicle. Towed sweepers are available in three types of drives:

straight mechanical, variable speed mechanical and variable speed hydrostatic.

The underbody airport sweeper is a large multipurpose unit that is pulled by a

carrier vehicle and is capable of plowing and sweeping snow and debris simulta-

neously. The band sweeper is similar to a front-mounted broom except it uses acontinuously turning horizontal band that is made of reinforced rubber. The

band has a number of protruding vertical ribs that are capable of moving snow

to the right and left of the travel path.

The focal point of any sweeper is the brush assembly. It must not only sweep

snow and slush from pavement surfaces at a specified speed, but also lift and

cast these materials off the surfaces and away from the path of travel. Brushes

come in different shapes and sizes. They can be mounted on a single tubular

29

Snow sweepers or

brooms are used

primarily to clean up

the residues left on

the pavement surface

by a plow or blower,

or in sweeping and

cleaning debris from

airport operational

areas



core or on several abutting cores, both of which receive power directly from the

carrier vehicle engine or an independent engine.

The choice in brush design and bristle composition depends on an airport’s

particular needs and the nature and type of snow normally received. Generally,

brushes having a mixed polypropylene/wire bristle composition will provide the

best overall sweeping results. Brushes are most effective when their contact with

the pavement surface produces a “flicking action” that dislodges snow and slush

and leaves a clean dry surface behind. Brush bristles are made of polypropylene

plastic (poly), wire, or a combination of one-half poly and one-half wire.

Three different types of brushes are available for use on airport sweepers:

wafers, tufted wire sections, and cassettes. Wafers are by far the most popular

type of brush used on airports.

Material Spreaders

The function of a material spreader is to provide a continuous, unrestricted,accurately metered flow of granular or liquid material to a pavement surface

over a predetermined spread area. A spreader unit consists of a material storage

compartment, a feed mechanism to carry the material to the discharge opening,

a metering device to control the discharge rate, and a distribution mechanism.

Depending on the type, spreaders are capable of spreading dry and liquid chemi-

cals and abrasives. Liquid material spreaders apply fluids to the pavement

surfaces through a spray applicator system consisting of a supply tank, pump,

flow rate monitor, and a spray bar equipped with nozzles. Tank capacities

usually range from 500 to 4,000 gallons.

Two methods exist to increase the friction coefficient of an iced or snow-packed

surface: (1) scarify the ice with a serrated blade and (2) apply granular material

(abrasives) to the surface. The use of abrasives needs to be carefully controlled

to reduce engine ingestion in turbojet aircraft. When applying abrasives, care is

used to help them adhere to the ice or snow since they can easily be blown away

by wind or scattered by aircraft operation. There are three approaches to reduc-

ing loss of abrasives: (1) they can be heated to enhance embedding into the cold

surface, (2) the granules can be coated with an approved de-icing chemical in

the stockpile or in the distributing truck hopper, or (3) diluted de-icing chemical

can be sprayed on the granules or the pavement at the time of spreading.

Snow and Ice Removal Techniques

It is important that any snow plowed off the runways not be of a height that will

interfere with pilot visibility or the wings, engines, and propellers of aircraft.

Furthermore, snow cleared from the runways should not be deposited within a

NAVigational AID (NAVAID) critical area.

NAVAID —Naviga-

tional Aid

The best type of snow

sweeper—made of

polypropylene and

wire bristle

30



Snow should be plowed to the prevailing downwind side of the runway to

reduce drifting. Eliminating windrows at the runway edge can also reduce the

formation of drifts onto the runway. These drifts, often called finger drifts,

frequently take the form of long, intermittent, and possibly narrow snow projec-

tions, which taper in width and height and can cause loss of aircraft directional

control. Snow fences can be used to minimize snow accumulation around

NAVAIDs and other sensitive facilities. Snow fences should not be placed so

that they penetrate any critical surfaces, and they should be outside of the

runway safety area.

If there is insufficient storage space for snow near the areas to be cleared and no

melting or flushing means are available, hauling snow to a disposal site may be

necessary. Careful consideration must be given to drainage when selecting a land

disposal site, as the ground can remain snow covered or wet long after all other snow

has melted. Seasonal vegetative growth can be delayed. Some airports have disposal

pits with melting devices in the ground to handle snow removal demands.

In heavy snow areas, the marking of edge lights by the placement of flexiblemarkers near the lights helps snow removal crews and pilots. The markers are

normally of a high contrast color such as international orange, which enhances

visibility. The height of the markers should be six inches outside the propeller

arc of the most critical airplane using the airport, and the markers need to be

securely fastened in place to avoid creating a foreign object damage (FOD)

hazard.

A NOTAM should be issued for the following winter operating conditions:

braking action reports, friction measurements, snow depths, plowed runways,

runway sanding or de-icing, snow banks, and runway light obscuration. The

procedures for pilot braking action reporting and runway friction reporting aregiven in the Aeronautical Information Manual (AIM). Relative to snow and

slush, depths normally greater than one-half inch require NOTAM publication.

The ACM is also the source for information regarding the placement of snow

banks near a runway, taxiway, or apron; though a snow bank exceeding 12 inches

is considered the norm for requiring a NOTAM.

The height of a snowbank on an area adjacent to a runway, taxiway, or apron

should be reduced to provide wing overhang clearance and preclude operational

problems caused by ingestion of ice into turbine engines or propellers striking

the banks. The maximum snow height profile developed for safe operationsshould be for the most demanding airplanes using an airport. This ensures that

props, wing tips, etc., do not touch the snow when a main wheel is located at the

edge of the full-strength pavement.

Some airports contract with private companies or municipal crews to conduct

snow removal operations. The principles of ensuring safety of operations apply

to them also. Any agreement needs to be clear and specific regarding (1) duties

and procedures for snow and ice control, (2) responsibilities for communications

and control, and (3) contingencies. Contractors should be given a copy of those

31

The height of themarkers placed next

to edge lights should

be six inches outside

the propeller arc of

the most critical

airplane that uses the

airport.

Objective 15

AIM —Aeronautical

Information Manual

A NOTAM should be

issued when there is

more than one-half

inch of snow on

paved surfaces and

when a snow bank

exceeds 12 inches.



portions of the ACM that apply to them, such as the snow plan and ground

vehicle operations. In addition, all airport leases and agreements should cover the

duties and responsibilities of lessees to carry out their snow and ice control

duties. It remains the responsibility of airport management to monitor all con-

tractor activities.

Airport Condition Reporting

Airport management is responsible for the timely notification of airport users

and the FAA of any conditions adversely affecting operational safety at the

airport. Several sections of Part 139 regulations require airport management to

have a system in place that will expediently notify users of any condition that is

not up to standard or that can affect aircraft operations. Airport management is

required to report deficient airport conditions, which could have an immediate

and critical impact on the safety of aircraft operations. Should it happen that

some element of Part 139 is not met, or an unsafe condition exists on the airport,air carrier activity for that area must be halted.

Notices to Airman (NOTAM)

The primary system used to convey safety information to airport users is known

as the Notice to Airman (NOTAM). The purpose of the NOTAM system is to

disseminate information on unanticipated or temporary changes to components

of, or hazards in, the National Airspace System until associated aeronautical

charts and other related publications can be amended.

The NOTAM system is important because airport operators have a duty to notifyusers of any change in published airport procedures or changes in the physical

facility. As an example, an airport manager should give timely and proper notice

of pavement or visual aids, which may have been damaged by a snowplow. If

the full width of a runway cannot be cleared of snow, the situation should be

reported in a NOTAM by giving details of the cleared width. This information

then allows each aircraft operator to judge the suitability of conducting opera-

tions since aircraft requirements differ.

The NOTAM system is not intended to be used to impose restrictions on airport

access for the purpose of controlling or managing noise, or to advertise data

already published or charted. NOTAM processing and dissemination are the

responsibility of FAA Flight Service Stations (FSS). When corrective actions

have been taken at the airport, the NOTAM should be canceled. The National

Flight Data Center (NFDC) in Washington, D. C. has overall management

responsibilities for the NOTAM system. At certain airports NOTAM issuance

may occur through the FAA air traffic control tower. However, airport manage-

ment is responsible for condition reporting and in these cases a letter-of-agree-

ment should be entered into, outlining the responsibilities for the NOTAM

issuance and dissemination.

The NOTAM system

is not intended to be

used to impose

restrictions on airport

access for the

purpose of control-ling or managing

noise, or to advertise

data already pub-

lished or charted.

The FAA Flight

Service Station (FSS)

is the processing

agency for NOTAM.

32



NOTAMs cover a variety of topic areas that fall under one of the following: move-

ment areas, lighting aids, air navigation aids, communications, services, special data,

and Flight Data Center NOTAMs. It is airport management’s responsibility to

promptly distribute information about any condition on or near the airport that

would prevent, restrict, or otherwise present a hazard to arriving and departing

aircraft. NOTAMs are often not the complete solution to providing adequate notifi-

cation at a particular airport. An internal communications system such as telephone,

computer, facsimile, or hand-carried written method that directly notifies air carrier

offices and tenants can be more timely and efficient.

Two types of NOTAM dissemination exist for airport condition reporting. A

NOTAM (L) is disseminated locally by the FSS to the area affected by the

hazard, aid, or service being advertised. A user of the airspace system may

become aware of a NOTAM (L) existence only by calling the FSS that has

jurisdiction for the issuing airport. A NOTAM (D) is one that carries distant

(national) dissemination by the FSS, thereby allowing someone outside the local

FSS area to become aware of the NOTAM without specifically requesting it.

If an airport is listed in the Airport Facility/Directory (AF/D), either of the NOTAM

dissemination methods can occur depending on the facility, equipment, or condition

being reported, though exceptions do exist. Generally, conditions qualifying for

NOTAM (L) dissemination are those associated with (1) runway and taxiway

information that does not restrict or preclude their use, (2) personnel and equipment

on or adjacent to the runway or taxiways, or (3) taxiway edge lights.

NOTAM (D) is issued in cases of an airport closure or the presence of conditions that

restrict or preclude the use of any portion of a runway or waterway. These can

include runway braking action reports; existence of runway contamination such as

snow, ice, slush, standing water, or rubber accumulation; changes in friction measur-ing values; friction measuring equipment out of order; restrictions or permanent

changes to Aircraft Rescue and Firefighting (ARFF) index; and outages of various

airport lighting and navigation aids, especially obstruction lighting outages.

Specific to snow or icing conditions, a NOTAM should include information on the

type of contaminant (wet snow, dry snow, slush), the depth of contaminant, whether

full or partial coverage; snow banks exceeding height standards, pavement tempera-

ture (if a SSI system is in place), type of device used and friction measurement

readings, braking action reports, chemical or abrasive treatments, runway closure

times, and obscuration of lights or markings. When issued, a NOTAM will includethe following information:

1. Identification of the affected airport facility and component;

2. Description of the affected component condition, which prompted the NOTAM;

3. The effective time period the component will be affected;

4. Name, address, and phone number of the person issuing the NOTAM;

5. To whom copies are distributed;

33

A letter-of-agreement

outlining the responsi-

bilities for the

NOTAM issuance and

dissemination should

be entered into by an

airport and the FAA

air traffic control

tower when the latter

is involved in

NOTAM issuance.

Two types of NOTAM

dissemination—

NOTAM (L) and

NOTAM (D)

NOTAM (D) is

issued in cases of an

airport closure or the

presence of conditions

that restrict or

preclude the use of

any portion of a

runway or waterway.



When reporting friction measurements, airport managers are to convey the runway

identifier, the type of device used, followed by the Mu number for each of the three run-

way segments, time of report, and a word describing the cause of the runway friction

problem. An example of a Mu report in the format used by ATC is as follows: “Runway

two seven, type of CFME, Mu 39, 37, 38 at one zero one eight Zulu, de-iced.”

Airports, certificated under FAR Part 139, must describe NOTAM issuance proce-

dures and required documentation in the ACM. Documentation of compliance is

necessary. A NOTAM log is required so that a manager can quickly access those

NOTAMs that are in effect and those that are not. When the FAA issues the

NOTAM, the time and duration of a NOTAM issuance is noted in Universal Time

Coordinated (UTC). The UTC system is stated in 10 digits (year, month, day, hour,

and minute). UTC replaced Greenwich Mean Time (GMT) in 1985. The acronym

ZULU continues in use, however, and it now represents the UTC date-time groups.

All times are expressed in the 24-hour clock. It is important that an airport document

the individual at the FAA facility who accepted the NOTAM information.

Airport Construction Activity

Periods of construction and maintenance on an airport present special prob-

lems in keeping aircraft, construction machinery, and personnel safely apart.

Obtaining contractor cooperation in this matter at the beginning is much

easier than trying to catch up later. The marking and lighting of construction

areas need to be spelled out clearly in the contract for incorporation into the

bid requirements. Planning for construction projects should always include

avoidance of damage to utilities.

Each bidding document (construction plans and/or specifications) for airportdevelopment work or NAVAlD installation involving aircraft operational areas

should incorporate an Airport Construction Safety Plan for the project. Con-

struction activities on an airport that are close to, or that affect aircraft opera-

tional areas or navigable airspace, are required to be coordinated with the FAA

and airport users before activities begin. Construction areas located within

safety areas require special attention in the project plans. Safety area encroach-

ments, improper ground vehicle operations, and unmarked or uncovered holes

and trenches near aircraft operating surfaces are the three most recurring threats

to safety during construction. Airport management is required to closely moni-

tor construction activity throughout its duration to ensure continual compliance

with safety requirements.

Certain airport projects, such as the construction, realigning, altering, activating,

or abandoning of a runway, landing strip, or associated taxiway, or construction,

or alteration of objects that affect navigable airspace, require formal written

notification to the FAA. On all AIP or PFC funded airport projects, a safety plan

must be developed. Key to the safety plan is the training of contractors and their

employees on how to operate safely on the airport.

Objective 15

The time and duration

of a NOTAM—noted

in Universal Time

Coordinated (UTC),

which replaced

Greenwich Mean

Time (GMT) in 1985

ZULU—represents

the UTC date-time

groups

34



Pedestrians and Ground Vehicles

Vehicular activity on airport movement areas should be kept to a minimum.

Airport Movement Areas (AMA) are the runways, taxiways, and other areas of

an airport which are used for taxiing or hover taxiing, air taxiing, takeoff, and

landing of air carrier aircraft, exclusive of loading ramps and aircraft parking

areas. Where vehicular traffic on movement areas cannot be avoided, it shouldbe carefully controlled. A basic guiding principle is that the aircraft always has

the right-of-way. At certificated airports, vehicle access to the AMA must be

controlled and identified easily. This includes vehicle markings, key or code

access, two-way radio communication, signal lights, traffic signs, flagmen,

escorts, or other means suitable for each particular airport.

The control of pedestrian and vehicular activity on airport operations areas is of high

importance. Airport management is required to establish and implement procedures

for access to, and operation on, movement areas and safety areas by both pedestrians

and vehicles. To heighten awareness of this safety issue and minimize runway

incursions and surface incidents, FAA requires an airport operator to provide spe-cific training on these operational procedures and requires that individual training

records be kept. The training requirements apply to airport employees, tenant

employees, construction crews, vendors and contractors.

With respect to vehicular traffic, aircraft safety is likely to be endangered by

four principle causes: increased traffic volume, non-standard vehicle traffic

patterns, vehicles without radio communication and markings, and operators

untrained in the airport’s procedures.

Public Protection

The requirements of Part 139 pertaining to public protection are oriented toward

inadvertent entry by persons or vehicles onto the AOA and the hazards that

exist. The prevention of intentional infiltration of airport security areas is within

the purview of the regulation on airport security, (Transportation Security

Administration—TSA) Part 1542. The ACM should provide for surveillance of

all of the safeguards on the airport for compliance with this provision.

Airport design requires the consideration of jet blast when locating facilities and

forming operational areas. The forces of jet blast far exceed the forces of prop

wash due to the high velocities of jet exhaust. In terminal, maintenance, and

cargo areas, personnel safety is the overriding consideration in design. The jet

exhaust velocities of most turbofan and turbojet engines can exceed 100 m.p.h.

for distances up to 200 feet behind an aircraft trying to break away from a

standstill. To mitigate the effects of jet blast on personnel safety, including

vehicular traffic near runway and taxiways, blast fences are used to deflect the

jet exhaust.

35

TSAR Part 1542—

contains stipulations

for prevention of

intentional infiltration

of airport security

areas.



Wildlife Hazard Management

Estimates by the FAA indicate that the economic cost from bird strikes are signifi-

cant— exceeding 400,000 hours of aircraft downtime and $216 million in direct

losses. Though bird strikes have been reported as high as 25,000 feet, the vast

majority of wildlife strikes occur below 600 feet above ground level. Birds are not

the only problem at airports. Other types of wildlife exist, including domesticanimals. For airports, wildlife includes mammals, birds, and reptiles, which exist

free in nature, and any domestic animals that are out of the control of their owners.

Wildlife becomes a hazard when the potential exists for a damaging aircraft collision

on or near the airport, or when certain conditions exist that can serve as an attraction

to wildlife that could pose an aircraft strike potential.

FAR Part 139 requires airport managers to show that they have established

instructions and procedures for the prevention or removal of factors on the

airport that attract—or might attract—wildlife. A wildlife attractant is consid-

ered to be any man-made structure, land-use practice, or natural geographic

feature that can attract or sustain hazardous wildlife within the landing ordeparture airspace, aircraft movement area, loading ramps, or aircraft parking

areas of an airport. These attractants can include, but are not limited to, architec-

tural features, landscaping, waste disposal sites, wastewater treatment facilities,

agricultural or aqua cultural activities, surface mining, or wetlands.

Part 139 requires airport management to conduct a Wildlife Hazard Assessment

when any of the following events occur on or near the airport:

1. An air carrier aircraft experiences multiple bird strikes.

2. An air carrier aircraft experiences substantial damage from striking wildlife.3. An air carrier aircraft experiences an engine ingestion of wildlife.

4. Wildlife of a size or in numbers capable of causing an accident event is ob

served to have access to any airport flight pattern or aircraft movement area.

A Wildlife Hazard Assessment must be conducted by a wildlife damage man-

agement biologist who has professional training and/or experience in wildlife

hazard management at airports or an individual working under the direct super-

vision of such an individual.

FAA Form 5200-7, Bird Strike Incident/Ingestion Report, is used to report

bird strikes to the FAA. It is available in the Aeronautical InformationManual (AIM), from a Flight Service Station (FSS) or from the FAA Air-

ports District Office (ADO). The form is also used to report other types of

wildlife collisions or incidents.

A Wildlife Hazard Assessment consists of (1) analyzing the events or circumstances

that prompted the research; (2) identifying the species, numbers, locations, local

movements, and daily and seasonal occurrences of wildlife observed; (3) identifying

and locating features on and near the airport that attract wildlife; (4) describing the

36

FAR Part 139 requires

airport managers to

show that they have

established instructions

and procedures for the

prevention or removal

of factors on the air-

port that attract—or

might attract—wildlife.

A wildlife attractant—

any man-made

structure, land-use

practice, or natural

geographic feature that

can attract of sustain

hazardous wildlife

Objective 16

An assessment of wildlife hazard is

required when any of

the following events

occur on or near the

airport: (1) an air

carrier aircraft

experiences multiple

bird strikes, (2) an air

carrier aircraft

experiences substantial

damage from striking

wildlife, (3) an air

carrier aircraft

experiences an engine

ingestion of wildlife,

and (4) wildlife of a

size or in numbers

capable of causing an

accident event is

observed to have

access to any airport

flight pattern or aircraft

movement area.



wildlife hazard to air carrier operations; and (5) recommended actions for reducing

the identified hazards on air carrier operations.

Upon completion the Wildlife Hazard Assessment, the document must be

submitted to the FAA Administrator for approval and a determination if a

Wildlife Hazard Management Plan is needed.

In addressing wildlife hazards at a certificated airport, one of three types of

entries is needed in the ACM: (1) a statement of negative activity; (2) a brief

statement of the no-hazard findings of a Wildlife Hazard Assessment; or (3)

a Wildlife Hazard Management Plan. In any event, the ACM should contain

instructions for reporting observed wildlife activity. If no wildlife activity

exists or none that triggers the Wildlife Hazard Assessment, a statement to

that effect must be recorded in the ACM. If it has been determined that an

airport must have a Wildlife Hazard Management Plan, it then becomes a

permanent part of the ACM.

Two other requirements are placed on the airport operator if a Wildlife HazardManagement Plan is mandated by FAA. The first is that a training program must be

conducted for airport personnel involved in wildlife management by a qualified

wildlife damage management biologist in order to provide these individuals with the

knowledge and skills needed to successfully carry out the Plan. Secondly, the

Wildlife Hazard Management Plan must be reviewed and evaluated annually.

The basic ingredient in an effective wildlife control program is not the tech-

niques used, but rather the abilities of airport personnel and the support of

management. Wildlife control is based primarily on two approaches: (1) habitat

modification and (2) active control. Active control includes scaring, dispersal,

trapping, and lethal control. Since birds are the primary hazard to aircraft,reducing the potential for bird strikes at airports involves one or more strategies.

Elimination of a food source and habitat modification are the primary method.

Habitat management is a planned activity, which begins with the identification

of habitat, consideration of alternatives for modification or elimination of the

habitat, and then the incorporation of changes into a long-term land-use man-

agement practice.

Habitat modification may require keeping grass at 10-14 inches for gulls, or 6

inches for other birds of prey. It could require removing trees, ponds, building

ledges, and other unnecessary perches and roosting areas. Other means forminimizing wildlife interference may include (1) installing at least a ten-foot

perimeter fence with barbed wire to prevent wandering wildlife, (2) placing

glycol storage basins and storm water ponds underground or providing netting

over them to keep birds out, (3) draining all standing water areas, (4) designing

ponds with a 4: 1 slope, and (5) using sweepers to remove worms from airport

hard surfaces.

FAA Form 5200-7,

Bird Strike Incident/

Ingestion Report, is

used to report to the

FAA not only bird

strikes but also other

types of wildlife

collisions or incidents.

37



Secondary strategies involve the active control of the birds through harassing

or frightening techniques and lethal control. These methods can be bird

distress call tapes, pyrotechnic devices, propane cannons, whistles, decoys,

shotgun blasts with screamers shells, high pressure water from fire hoses,

and even papier-mâché owls to frighten birds. There is also the use of

chemical treatment to cause dispersal and movement of flocks. Lethal con-

trol or the killing of wildlife through the use of chemicals, firearms or other

mechanical means normally requires a depredation permit from a state or

federal Fish and Wildlife Service. Since birds and animals adapt to the

various strategies, effective wildlife control requires continuous changes to

the method used.

Large numbers of wildlife that are hazardous to aircraft are known to be

attracted to such things as waste disposal operations, waste water treatment

facilities, settling ponds, and artificial marshes. When located within certain

distances of the airport, they are considered incompatible with safe airport

operations. Accordingly, measures to minimize hazardous wildlife attraction

should be developed.

The Environmental Protection Agency (EPA) requires any operator proposing a

new or expanded waste disposal operation within five statute miles of a runway-

end to notify the appropriate FAA Regional Airports District Office and the

airport operator of the proposal. The EPA also requires owners or operators of

new Municipal Solid Waste Landfill (MSWLF) units—or lateral expansions of

existing MSWLF units that are located within 10,000 feet of any airport run-

way-end used by turbine powered aircraft or within 5,000 feet of any airport

runway-end used only by piston-type aircraft—to demonstrate successfully that

such units are not hazards to aircraft.

The FAA recommends that, to the extent practicable, operators of AIP funded

airports oppose off-airport land-use changes or practices within the distances

noted above that may attract hazardous wildlife. Failure to do so could place the

airport in noncompliance with applicable grant assurances. It is the responsibil-

ity of airport operators, sponsors, planners, and land-use developers to consider

whether any proposed land uses, including new airport development projects,

would increase the wildlife hazard. Because grant assurances and certification

are affected, AIP funds can be used for wildlife control.

All species of wildlife can pose a threat to aircraft safety. However, some spe-cies are more commonly involved in aircraft strikes than others. Gulls, water-

fowl, raptors, doves, vultures, blackbirds/starlings, corvids, wading birds, and

deer are the most common wildlife groups reported as being involved in damag-

ing strikes to aircraft in the United States.

Airports often experience other localized wildlife problems with diverse animals

such as cows, armadillos, rabbits, alligators, moose, prairie dogs, coyotes, and

groundhogs. Because the wildlife species and the size of the populations at-

MSWLF—Municipal

Solid Waste Landfill

AIP funds can be used

for wildlife control.

38



tracted to the airport environment are highly variable, it is important for airport

management to identify those land-use practices in the airport area that serve to

attract any such hazardous wildlife. The U. S. Department of Agriculture

(USDA) has expertise in the management of wildlife problems. The Wildlife

Services Department of the USDA can provide assessments and advice for

dealing with wildlife problems and control.

Airport operators with wetlands located on or near airport property should be

alert to any wildlife use or habitat changes that could affect safe aircraft opera-

tions. When expanding existing airports in or near wetlands, the wildlife hazards

should be evaluated and minimized through a wildlife management plan. The U.

S. Fish and Wildlife Service (USFWS) and the U. S. Army Corps of Engineers

(COE) can assist and make a determination as to whether or not an area would

qualify as a wetland.

The movement of storm water away from runways, taxiways, and aprons is a

normal function on most airports and is necessary for safe aircraft operations.

Both detention and retention ponds are used for the purpose of controllingrunoff and protecting water quality. Detention ponds hold storm water for short

periods (typically three hours or less), while retention ponds hold water

indefinitely. They both can attract hazardous wildlife. Retention ponds are

more attractive to hazardous wildlife than detention ponds because they

provide a more reliable water source. To facilitate hazardous wildlife con-

trol, the FAA recommends using steep-sided, narrow, linearly shaped,

riprap-lined, water detention basins rather than retention basins. When

possible, these ponds should be placed away from aircraft movement areas

to minimize aircraft-wildlife interactions. All vegetation that provides food

or cover for hazardous wildlife in or around detention or retention basins

should be eliminated.

Airport management often promote revenue-generating activities such as

agricultural crop production on airports. Any proposed on-airport agricul-

tural operations need to be carefully reviewed as to its attraction to wildlife

since such use may create potential hazards to aircraft by attracting wildlife.

If a problem with hazardous wildlife develops, an on-site inspection by the

USDA, Animal Damage Control or other qualified wildlife biologist should

be conducted. Regardless of the source of the attraction, prompt remedial

actions to protect aviation safety are recommended.

The key to effective wildlife control is not only detecting wildlife on the

airport but also anticipating its presence. It is important to pay attention to

weather, increased bird activities associated with migration, seasonal differ-

ences, and attractiveness of activities being performed on the airport. If an

existing land-use practice creates a wildlife hazard and the land- use practice

or wildlife hazard cannot be immediately eliminated, airport management is

obligated to issue a NOTAM and encourage the land owner or manager to

take steps to control the wildlife hazard and minimize further attraction. If

To facilitate hazardous

wildlife control, the

FAA recommendsusing steep-sided,

narrow, linearly

shaped, riprap-lined,

water detention basins

rather than retention

basins.

39

Key to effective

wildlife control—

detecting wildlife and

anticipating its

presence



the condition is expected to last indefinitely, the NOTAM can become a

permanent record within the Airport/Facility Directory. Such an entry in the

A/FD needs to be accompanied by a Wildlife Hazard Assessment.

Summary

Airport Operations is at the heart of an airport’s dynamic environment. In

that capacity, the operators of all federally certificated airports are required

to meet minimum safety standards required or prescribed by Part 139 of the

Federal Aviation Regulations (FAR), Certification of Airports. To accom-

plish this task of operating the airport in a safe and efficient manner, airport

operating departments are required to develop an Airport Certification

Manual (ACM). The ACM covers key airport operational issues and de-

scribes how the airport intends to comply with the statutory requirements of

FAR Part 139.

The central theme and purpose of the ACM is to be a useful working docu-ment, to help personnel maintain a safe airport, and complying with the

regulations. The most critical element to ensure safe operations is regular

self-inspections of the airport in order to identify those conditions that are

hazards or have the potential to become hazards. Establishing procedures to

correct deficiencies noted during the inspections is also the responsibility of

the operating departments.

Because of the day-to-day attention to details by personnel in Airport Opera-

tions, the United States airports are a major component of the safest aviation

system in the world.

40



41

Appendix A: Standard for Airport Sign System



Appendix B: ACM Elements - Section 139.203(B)

42



Study Questions

1. What are the changes in certification requirements under the most recentFAR Part 139?

2. How are the four classes of airports defined in the most recent

FAR Part 139?

3. What is the purpose of an airport certification manual (ACM)? What doesit provide? What does it emphasize?

4. What are the key components that an airport self-inspection program?What type of activities do these components address?

5. What affects pavement strength and wear? How does poor pavementaffect aircraft? How can traction and friction be maintained and improved?

6. What are the major causes of pavement deterioration? How can

deterioration be mitigated?

7. How are pavement conditions measured? What is the effect of differentreadings?

8. What are airport movement and safety areas? What criteria affect them?

9. What types of approach lighting systems exist? What are their operatingcriteria?

10. What are the marking and signage requirements at airports? Whatinscriptions and colors are used for markings and signs?

11. How do snow and ice affect pavement surface? What responsibility doesairport management have to mitigate the effects?

12. Why is it important to have a snow and ice plan? What does such a planconsist of?

13. What are the various methods for removing snow and ice from pavementsurfaces?

14. What are the basic properties of anti-ice and de-ice compounds?

15. What does NOTAM mean? When should a NOTAM be issued? Whatinformation does a NOTAM convey?

16. When should a Wildlife Hazard Assessment at an airport be conducted?What should such a study contain?

Documents

ACC Module14