Research & Development Annual Review 2005

Administration

Federal Aviation
Introduction 1

Aircraft Safety 2

Airport Technology 12

Air Traffic Management 18

Aviation Weather 20

Commercial Space 26

Environment & Energy 28

Human Factors & Aeromedical 36

Information Technology 48

Safe Flight 21/Alaska Capstone 50

Contents
Every day the aviation community faces a number of challenges 

that range from ensuring the health and safety of passengers 

and crew to protecting the environment, increasing capacity and 

efficiency, and maintaining an aviation system that is performance-based and human-centered. To meet these challenges, 

we are dedicated to four goals: increased safety; greater capacity; international leadership; and organizational excellence. 

FAA’s 47,000 employees are making a difference every day as 

they work to achieve these goals and create a better air transportation system. 

We are making a 

difference every day.

We are succeeding, in part, because of the dedicated work of 

our research and development program. Our researchers, scientists, engineers, and professional staff are creating the tools, 

technologies, and procedures that continue to improve the air 

transportation system. We are conducting critical research for 

aviation’s future.

The Fiscal Year (FY) 2005 R&D Annual Review highlights another successful year for our researchers. In these pages, you 

may review some of our ongoing work in support of the Agency’s 

strategic mission and goals. For additional information on the 

R&D program, please see the National Aviation Research Plan, 

which includes a description of our R&D projects, our research 

partners, budget information, and expected future results.
Evaluating Multiple-Site Damage in 

Fuselage Structure

In 1988, the FAA established a broad regulatory program 

to ensure the structural integrity of aging aircraft following 

the near catastrophic structural failure of a 737 flight to Honolulu, Hawaii. Since that accident, in which small cracks 

emanating from multiple rivet holes in a debonded lap joint 

resulted in a large portion of the fuselage crown tearing 

apart, researchers have focused efforts on developing 

methodologies to assess multiple-site damage in aircraft 

structures. (At the joint, the two parts of the fuselage are 

bonded, and then mechanically fastened with three rows 

of rivets. A debond happens when the glue in the joint no 

longer holds up. This results in the rivets carrying all the 

load across the joint, and when this happens, the rivet 

holes become hot spots for cracks to develop.) Research 

efforts sponsored by the FAA, National Aeronautics and 

Space Administration (NASA), and the Department of Defense (DoD) include the development of various analytical 

tools that address this complex problem at several levels. 

Researchers have developed rigorous numerical methods 

and simplified engineering approaches to predict crack 

initiation, growth, linkup, and residual strength. 

In an effort to provide experimental data for model validation, researchers used the FAA Full-Scale Aircraft Structural 

Test Evaluation and Research (FASTER) facility to investigate multiple-site damage initiation and growth in a pristine 

fuselage lap joint panel. The test panel, representative 

of a generic narrow-body fuselage, included a stiffened 

structure containing six frames, seven stringers, and a 

four-rivet row lap joint. During the fatigue test, researchers monitored and recorded damage formation and growth 

in the lap joint in real time using the Rotating Eddy-Current Probe (RECP) system and high-magnification visual 

methods. Researchers initially detected cracks in the outer 

critical rivet row A in the lap joint after 12,600 flight cycles 

take off and landing using RECP. While manufacturers of 

today’s large commercial aircraft originally anticipated their 

aircraft would remain in service for twenty years accumulating 60,000 flights, many are currently being flown longer. 

Researchers found visually detectable cracks in the rivet 

head of the critical rivet row after 51,500 cycles and then 

in the lap joint outer skin after 80,500 cycles. The first 

multiple site damage linkup occurred after 106,217 cycles, 

forming a lead crack. Subsequently, the lead crack grew 

very rapidly along the outer rivet row eventually forming a 

16.04” two-bay crack after 107,458 cycles.

Researchers conducted a residual strength test to determine the load-carrying capacity of the panel. They found 

that the panel failed catastrophically when the lead crack 

extended instantaneously in the lap joint across four skin 

bays. Researchers examined the fracture surfaces using 

a high magnification scanning electron microscope to 

determine initiation sites and mechanisms and to reconstruct subsurface crack growth behavior from marker band 

2 

Aircraft Safety
locations in the first visually detected crack. The results 

from this examination of a single crack revealed multiple 

initiation sites and extensive fretting damage along the 

faying surface of the skin. Results from this study provide 

key data to verify and validate fatigue damage assessment 

approaches. Additional details about this research can be 

found in Ahmed, A. and Bakuckas, J. G., Development of 

Multiple-Site Damage in Fuselage Structure (DOT/FAA/AR05/38, September 2005), on-line at http://aar400.tc.faa.

gov/Programs/AgingAircraft/Structural/reports/reports.htm.

Assessing Commercial Aircraft Lap 

Joint Damage

As part of its National Aging Aircraft Research Program, 

the FAA is developing and testing new technologies and 

techniques to predict, detect, and mitigate the deterioration of aircraft structures. Researchers are conducting 

comprehensive tear down inspections, collecting data, 

and performing structural evaluations and assessments 

of older, operational aircraft. During the past fiscal year, 

researchers disassembled the fuselage of a retired Boeing 

727 aircraft to collect data on an aircraft near the end of 

its design service goal of 60,000 flights. During this tear 

down, researchers focused attention on the fuselage crown 

lap joint, which has a known history of multiple-site damage 

cracking. 

Researchers developed a tear down procedure to characterize the state of damage to measure crack sizes, shapes, 

and distributions, to study crack initiation sources and sites, 

and to reconstruct crack growth histories through striation 

counts. Examination of the lap joint found over 350 cracks 

in 270 rivet holes in a fuselage section approximately 30 

feet in length. The cracks typically ranged in size from 0.01 

to 0.2 inches. The majority of holes had multiple cracks, up 

to six or seven in some cases, in a starburst pattern around 

the lower two-thirds region of the hole in the lower skin. 

Many of these cracks had multiple origins at the corner of 

the hole and the faying surface, which eventually formed a 

contiguous crack. 

The FAA will use the data from this study to: characterize 

crack initiation; crack linkup, and residual strength; assess 

the inspection capability of nondestructive inspection techniques to detect cracks; and determine widespread fatigue 

damage average behavior in the structures removed and 

examined. Additional details about this research can be 

found in Bakuckas, J. G., Bigelow, C. A., Carter, A., and 

Steadman, D., “Destructive Evaluation and Extended 

Fatigue Testing of Retired Aircraft Fuselage Structure,” 

Proceedings of the 23rd Symposium of the International 

Committee on Aeronautical Fatigue, June 6-10, 2005, 

Hamburg, Germany, on-line at http://aar400.tc.faa.gov/Programs/AgingAircraft/Structural/reports/reports.htm.

Detecting Structural Cracks in 

Helicopters 

Increasing niche applications, growing international markets, and the emergence of advanced rotorcraft technology 

are expected to increase greatly the use and number of helicopters over the next decade. As the helicopter industry 

expands and adapts to new situations, it is critical to ensure 

the appropriate application of nondestructive inspection 

equipment to manage structural safety. Currently, the 

capabilities for nondestructive inspection of rotorcraft are 

essentially limited to the techniques established for fixed 

wing aircraft. Since the environments in which rotorcraft 

operate are significantly different than fixed wing aircraft, 

much smaller cracks must be found than current nondestructive inspection techniques can detect 

Researchers at the FAA Airworthiness Assurance Nondestructive Inspection Validation Center at Sandia National 

Laboratories recently collaborated with Bell Helicopter and 

others in the rotorcraft industry to evaluate nondestructive 

inspection capabilities aimed at detecting small cracks 

under button head or raised head fasteners. The FAA and 

rotorcraft industry identified this as an important near-term 

issue because cracks in high cycle fatigue joints, such as 

those found in the tail boom and transmission assembly 

regions, can quickly grow from small initiation lengths to 

critical lengths in a relatively few number of flight hours.

Researchers designed a series of tests to isolate and 

study the effects of different rivet scenarios using various 

eddy current and ultrasonic inspection techniques. Two 

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of the most promising advanced methods are a remote 

field eddy current technique and a linear array ultrasonic 

system. The remote field eddy current technique is based 

on electromagnetic induction and is used to identify or 

differentiate among a wide variety of physical, structural, 

and metallurgical conditions in electrically conductive metals. Linear array ultrasonic inspection injects a short pulse 

of ultrasonic sound into a component to detect internal 

defects. Both techniques demonstrated the ability to detect 

small cracks under the rivet heads. Researchers are now 

working with industry to transfer these inspection methods 

to industry for routine use in rotorcraft maintenance depots. 

Successful transition will aid the rapid integration of these 

improved nondestructive inspection methods in a cost-effective manner.

Improving the Usability and 

Reliability of Aviation Technical 

Manuals

Aviation maintenance technical manuals provide critical 

information to aircraft maintenance, design, and inspection personnel. These manuals have increased in number 

and complexity as aviation systems have become more 

sophisticated, and the process for making changes to 

these manuals has grown increasingly cumbersome and 

expensive.

Research shows that the current generation of technical 

manuals may contain an unacceptable level of built-in errors generated from within the publication process. Tasks 

that are inadequately or incorrectly described are likely 

to generate process errors. Process errors, in turn, can 

lead to equipment failure and costly rework. In addition, 

researchers have discovered that some procedures are 

difficult to perform as described in technical manuals. 

To improve the quality of these technical manuals, the 

FAA, under a cooperative agreement with Wichita State 

University National Institute for Aviation Research (NIAR), 

and in conjunction with aircraft manufacturers (Raytheon, 

Bombardier, Cessna, and Boeing), conducted experiments with engineers and technical writers to identify the 

most effective techniques for developing and validating 

maintenance procedures for technical manuals. Based on 

the research results, they developed the on-line Evaluation Toolbox for Aviation Technical Writers (http://www.niar.

twsu.edu/humanfactors/toolbox/default.htm). This toolbox 

contains concepts, evaluation methods, tools, templates, 

and references to educate and assist technical writers in 

developing better technical documentation.

At a June 2005 workshop sponsored by the FAA, NIAR, 

and the aircraft manufacturers, researchers disseminated 

their results to approximately 50 technical writers from the 

aircraft manufacturers, the FAA, National Transportation 

Safety Board, and Boeing, as well as directors of technical 

publications from Cessna, Bombardier, and Raytheon. The 

local general aviation manufacturers are currently working 

with the Kansas Technology Enterprise Corporation, a private/public partnership established by the state of Kansas 

to promote technology-based economic development, and 

to develop a training program for technical writers based 

on this research. The FAA also plans to use the research 

results to develop an advisory circular.

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Studying Side Load Factors During 

Aircraft Ground Operations

The FAA Operational Loads Monitoring Research Program 

is defining the service-related factors that affect the operational life of commercial aircraft by collecting, analyzing, 

and publishing data in statistical formats that will enable 

the FAA to reassess existing certification criteria. Equally 

important, the new data will also enable the FAA, the aircraft 

manufacturers, and the airlines to understand better and 

control those factors that influence the structural integrity of 

commercial transport aircraft. 

In support of a number of FAA certification initiatives, FAA 

researchers completed a study of ground operations using 

airplane data recorded by digital flight data recorders to assess 0.5G limit lateral load criteria for wide body aircraft, in 

particular, the Airbus 380. Airbus had requested a reduction 

in the 0.5G Limit Load specified in Title 14 Code of Federal Regulations (CFR), Part 25.495. The study provided 

the technical data for the regulatory agencies to make an 

informed decision. Lateral acceleration certification criteria 

described in the CFR for commercial aircraft operations are 

based primarily on the two ground events considered the 

most critical to the aircraft structure: the touchdown and 

ground turns.

Researchers found a significant difference in the touchdown 

lateral acceleration between wide body airplanes and narrow body airplanes. Data show that, in general, the size 

and weight of the aircraft is a significant factor affecting the 

magnitude of the touchdown lateral acceleration. Smaller 

airplane models, such as the Boeing 737, tend to incur most 

of their higher lateral acceleration values while turning, probably because of higher speed and landing gear configuration. Heavier airplanes are prone to encounter lower values 

of lateral acceleration while taxiing and tend to have their 

highest lateral accelerations occur during the touchdown 

event and subsequent rollout.

As a result of this work, the FAA Aviation Rulemaking 

Advisory Committee recommended a special condition to 

14 CFR 25.495 to reduce the ground turning requirement 

from 0.5G to 0.42G for the Airbus A-380. The results of this 

study are documented in Study of Side Load Factors During 

Ground Operations (Technical Report DOT/FAA/AR-05/7), 

which can be found on-line at http://www.tc.faa.gov/its/worldpac/techrpt/ar05-7.pdf.

Updating and Commercializing the 

Metallic Materials Properties 

The Metallic Materials Properties Development and Standardization (MMPDS) process is an effort led by the FAA to 

collect, analyze, and publish statistically based, standardized 

information on aircraft and aerospace material and fastener 

properties that comply with FAA regulations. The publication, 

Metallic Materials and Elements for Aerospace Vehicle Structures, formerly known as Military Handbook-5 (MIL-HDBK5), is recognized worldwide as the most reliable source for 

verified design standards needed for metallic materials, 

fasteners, and joints used in the design and maintenance of 

aircraft, missiles, and space vehicles. 

In August 2005, Battelle Memorial Institute issued the first 

commercial version of the MMPDS-02 handbook. The FAA 

granted Battelle, a not-for-profit organization, an exclusive 

license, subject to annual renewal, to reproduce and distribute the handbook and related products. The latest version 

of the handbook includes descriptions of 12 new alloys. The 

volume includes: 

Volume 1 - Introduction and Guidelines (Chapters 1 and 9) 

Volume 2 - Steel and Magnesium Alloys (Chapters 2 and 4) 

Volume 3a - 2000-6000 Series Aluminum Alloys (First part of 

Chapter 3) 

Volume 3b - 7000 Series and Cast Aluminum Alloys (Second 

part of Chapter 3) 

5
Volume 4 - Titanium and Heat-Resistant Alloys (Chapters 

5 and 6) 

Volume 5 - Miscellaneous Alloys & Structural Joints 

(Chapters 7 and 8)

Additional information can be found on-line at http://www.

mmpds.org.

Developing Nondestructive Inspection Methods for Composite Aircraft 

Structures

The use of composite materials in commercial large 

transport aircraft structures is becoming more common as 

evidenced by the planned production of the Boeing 787 

and the production of the Airbus 380 aircraft. Composites 

offer lighter weight and equivalent strength to the metals 

they replace. By the nature of their fabrication, however, 

composites offer new challenges to inspectors. Composite inspection often requires scanning of large areas for 

subsurface damage. This can be time-consuming and may 

require intricate mapping of the surface when damage is 

detected mapping and interpretation of the inspected area.

Composite sandwich panels with honeycomb cores are 

widely used in aircraft as secondary structures and control 

surfaces for rudder skin panels, spoilers, flaps, engine 

cowlings, landing gear doors, and body fairings. When a 

honeycomb structure is crushed or damaged, the damaged 

area may be removed and repaired with patches of similar 

layers of material bonded in place at an airline composite 

shop. Repairs are occasionally performed aboard aircraft 

and cured without the benefit of an autoclave, which may 

introduce more porosity than typically found in undamaged 

structures. A primary maintenance concern is how to determine whether these repairs are structurally sound.

Because traditional ultrasonic inspection techniques are not 

as effective on composites, the FAA funded Iowa State University, through the FAA Airworthiness Assurance Center 

of Excellence, to develop a nondestructive inspection technique for composite structures. Researchers developed 

a prototype air-coupled ultrasonic system, comprised of a 

computer and scanning equipment, for assessing composite damage and repairs. This is a noncontact ultrasonic 

technique in which air acts as a coupling medium between 

the ultrasonic transducer surface and the object under examination. Hence, in contrast to conventional techniques, 

no coupling gel or immersion in liquid is required.

Field tests of the new system proved successful. For 

example, researchers used the system to map the extent 

of damage to rotors on a Blackhawk helicopter at the Iowa 

Army National Guard Unit. They also conducted successful tests on a set of 42 honeycomb panels containing 

engineered flaws. This work marks the first demonstration of a non-contacting, non-contaminating air-coupled 

ultrasonic inspection tool in the field. Efforts are currently 

underway to license the technology and transfer it into the 

commercial sector. 

Creating Flame Retardant 

Composites

The use of composite structures in both commercial and 

general aviation aircraft is increasing because of advantages such as lower weight, better fatigue performance, no 

corrosion, and better design flexibility. The new Airbus 380 

and 350 for example, are expected to have over 20 percent 

of the structural weight in composites, including a carbon 

fiber reinforced epoxy wing. About 50 percent of the 

structural weight of the new Boeing 787 will be composites, 

making it the first large commercial airliner with a composite fuselage and wings. Although currently no fire resis6 
tance or flammability requirements exist for exterior polymer 

composite structures on airplanes, aircraft manufacturers 

must demonstrate that those composites provide equivalent 

safety to the current material (aluminum alloy).

Polymer composites can be flammable, so halogen (bromine and chlorine) containing flame retardant chemicals 

are normally added to reduce their flammability. However, 

halogen-containing flame retardants are being phased out 

all over the world because of environmental concerns, so 

FAA researchers are now working to identify new, non-halogen, environmentally-friendly strategies for reducing the fire 

hazard of polymer aerospace composites. To this end, use 

of epoxy resins and/or curing agents containing phosphorus, which is an environmentally-acceptable alternative to 

halogens, is being incorporated into existing aerospace 

epoxy formulations at low levels to provide low flammability structural composites with little or no compromise in 

processing, handling, and mechanical properties. Working 

with the FAA, NASA researchers synthesized epoxy resins 

and their curing agents containing phosphorus, characterized the phosphorus-containing epoxy formulations (resin 

and curing agent) by thermal analysis and flame tests, and 

measured their mechanical properties. NASA showed that 

the fracture toughness and compressive strength of several 

cured formulations showed no detrimental effect due to 

phosphorus content. 

At the FAA, researchers used fire calorimetry and microscale combustion calorimetry to measure the flammability 

of the compounds. They observed a three-fold reduction 

in flammability for the phosphate epoxies, which contained 

the most phosphorus-oxygen chemical bonds. However, 

testing indicated that phosphorus in the compounds tested 

had no significant effect on flame chemistry. Instead, 

researchers attributed flammability reduction to the creation 

of a protective layer of char catalyzed by the phosphorus on 

the surface of the composite. The activity of phosphorus as 

a char catalyst increased with the number of phosphorusoxygen bonds in the curing agent or epoxide, indicating that 

the catalyst for char formation is a phosphorus oxide or a 

phosphorus acid. 

The work will be published in the journal Polymer (P.M. 

Hergenrother, C.M. Thompson, J.G. Smith Jr., J.W. Connell, 

J.A. Hinkley, R.E. Lyon, and R. Moulton, “Flame Retardant 

Aircraft Epoxy Resins Containing Phosphorus” Polymer 46, 

5012-5024).

Licensing the Microscale Combustion Calorimeter

In a fire, the temperature at which a combustible material 

ignites (the ignition temperature), the rate of mass loss as 

the material subsequently burns (the burning rate), the rate 

at which the material releases heat in flaming combustion 

(heat release rate), and the maximum amount of heat that 

can be released by burning (heat of combustion) are the 

primary indicators of the material’s hazard to life and property. The time available for passengers to escape from a 

fire in an enclosure such as an airplane cabin is determined 

by the growth rate of the fire. The fire growth rate increases with the ignitability and the heat release rate (HRR) of 

the materials in the enclosure. Resistance to ignition can 

be defined as the minimum (critical) heat flux or fire size 

below which the material will not burn. The critical heat flux 

(CHF) is related to the ignition temperature of the material 

(Tign) as CHF = σ T4ign where σ = 5.7 W/m2-K4 is the 

Boltzmann constant. HRR is the product of the mass loss 

rate (MLR) or burning rate and the heat of combustion of 

the material (HOC): HRR = MLR x HOC.

In practice (i.e., in fire calorimeters), mass loss rate and 

heat release rate are measured continuously during the 

test by weighing the sample and measuring the amount 

of oxygen consumed by combustion, respectively. At the 

present time these fire hazard indicators, ignition temperature, heat release rate, and heat of combustion, are 

measured using procedures published by the American 

Society for Testing and Materials (ASTM) in at least three 

separate devices requiring at least one kilogram of material 

to complete all of the tests. Consequently, an instrument 

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and method that measures ignition temperature, burning 

rate, heat release rate, and heat of combustion in a single, 

rapid, and quantitative test under fire-like conditions using 

a small amount (milligrams) of substance is of theoretical 

and practical importance to fire protection engineers and 

materials scientists.

The FAA filed an application for a new patent with the Patent and Trademark Office in December 2005 for a Flammability Tester. The Flammability Tester combines methods of 

thermal analysis and fire calorimetry in a single device that 

simultaneously measures multiple flammability parameters 

(HRR, HOC, and Tign) of combustible materials using 

small samples. The method and apparatus is useful for 

quickly and accurately testing milligram and larger samples 

of combustible materials. 

On January 18, 2005, the FAA licensed The Govmark 

Organization, Inc., Farmingdale, New York to manufacture 

and sell the Flammability Tester. On March 11, 2005, the 

FAA also licensed Fire Testing Technology, Ltd., in the 

United Kingdom, to manufacture and sell the Flammability 

Tester.

Evaluating the Flammability of 

Aircraft Electrical Wiring

Over the years, a number of aircraft wire insulation 

materials have been used throughout the aircraft. The 

composition of the wire insulation is dependent upon the 

wire location (environmental conditions) and its purpose. 

Examples of common wire insulation materials include 

aromatic polyimide, and fluoropolymer insulation, such as 

ethylene tetrafluoroethylene, polyvinyl chloride/nylon, and 

crosslinked-polyalkene. As technology has progressed, 

improvements in aircraft wiring have been made. Some of 

these improvements include arc propagation resistance, 

a decrease in smoke production, and better flammability 

properties. 

The FAA issued its first flammability test requirement for 

electrical wiring in 1972, mandating, among other things 

that insulation on electrical wire or cable installed in any 

area of the fuselage must be self-extinguishing when subjected to what is called the 60-degree test. The 60-degree 

Bunsen burner test determines the resistance of electrical 

wire insulation to flame. The pass/fail criteria are based on 

the burn length, after-flame time, and drip-flame time. The 

FAA is now examining the currency of this flammability test 

requirement in light of the advent of new wiring and insulation materials and manufacturing processes to ensure the 

maximum safety for travelers.

To test the adequacy of the flammability requirement, 

researchers subjected samples of electrical wiring and 

electrical wiring insulation to the standard flammability test. 

They tested twelve specimens, and all but two passed the 

test. The 60-degree test did not discriminate very well 

between the performances of different materials. The difference in burn length for the best and the worst materials 

proved minimal. 

In a second phase of testing, researchers evaluated five of 

the original twelve types of wire and cable, using a second 

type of flammability test. Researchers found the Polytetrafluoroethylene (PTFE)/polyimide/PTFE construction 

to be the overall best performer. Another round of tests 

confirmed these results.

Test results showed that the 60-degree single wire Bunsen 

burner flammability test might not be adequate to qualify 

wire when bundled and subjected to a severe ignition 

source. The FAA is currently expanding its research to 

upgrade the fire test criteria for electrical wiring and materials in other hidden areas, such as the attic above the cabin 

ceiling, areas beneath the floor, and areas in or around the 

8 
lavatories. The test results are documented in An Evaluation of the Flammability of Aircraft Wiring (Technical Note, 

DOT/FAA/AR-TN04/32), which can be found on-line at 

http://www.fire.tc.faa.gov/pdf/TN04-32.pdf.

Studying In-Flight Flammability and 

Fuel Tank Inerting

Recent FAA research has illustrated that fuel tank inerting 

could be practical in the commercial fleet, thus reducing the 

risk of fuel tank explosions, if air separation modules could 

be used effectively in an inert gas generation system. Fuel 

tank inerting is accomplished by displacing the air in the 

existing empty tank space above the fuel (ullage) with nitrogen or nitrogen-enriched air generated by an onboard inert 

gas generation system. The FAA fuel tank inerting initiative 

focuses on center wing or body style tanks in the commercial transport airplane fleet. These tanks are frequently not 

used by the aircraft operators, and are likely to be empty on 

most domestic flight operations. 

To demonstrate the use of hollow-fiber membrane air separation modules, the FAA, with the assistance of several 

aerospace companies, developed a prototype onboard 

inert gas generation system that uses aircraft bleed air to 

generate nitrogen-enriched air at varying flows and purities 

during a commercial airplane flight cycle. Additionally, 

the FAA developed models and experimental methods to 

predict oxygen levels and the progression of flammability in 

an aircraft fuel tank ullage throughout a typical flight cycle.

In conjunction with NASA aircraft operations personnel, 

FAA researchers conducted a series of ground and flight 

tests to evaluate the FAA inerting system and examine 

the flammability of both the center wing and one inboard 

wing fuel tank. The inerting system was mounted in the 

pack bay of NASA’s Boeing 747 SCA, which is used for 

transporting the Space Shuttle Orbiter. During testing, researchers used special instrumentation to measure aircraft 

flight parameters, as well as fuel tank oxygen concentration 

and flammability, to understand better the ability of the FAA 

inerting system to reduce the flammability exposure of the 

center wing tank of a commercial transport airplane.

Test results prove the viability of the FAA inerting system, 

validating the primary research assumptions. Flammability measurements from both the center wing tank and the 

wing tank showed trends consistent with experimental and 

computational analysis previously performed and allowed 

for the potential improvement of ullage flammability models. 

A description of the flight test program and findings are 

contained in Evaluation of Fuel Tank Flammability and the 

FAA Inerting System on the NASA 747 SCA (DOT/FAA/AR04/41), authored by Mike Burns, William Cavage, Robert 

Morrison, and Steven Summer. The report is available 

on-line at http://www.fire.tc.faa.gov/pdf/05-25.pdf.

In December 2005, as a result of this research, the FAA 

issued a notice of proposed rulemaking for new rules. That 

would require operators and manufacturers of transport 

category aircraft to take steps, that in conjunction with other 

required actions, should greatly reduce the chances of a 

catastrophic fuel tank explosion.

Improving the Fire Safety of 

Insulation Material

The FAA recently proposed an Airworthiness Directive (AD) 

that would require U.S. airlines to remove thermal acoustic 

insulation blankets made of a Mylar® film called AN-26 

from over 800 of their transport aircraft. Service experience and tests conducted by FAA fire safety researchers 

prompted the proposed AD. The tests demonstrated that 

the film consistently could be ignited by an electrical arc 

and could cause a fire aboard an aircraft. 

Aircraft insulation blankets are used primarily to protect 

passengers and crew from engine noise and, at high 

altitudes, from frigid temperatures. They are typically 

composed of a batting material, generically referred to as 

fiberglass, with a covering of film that both contains the 

batting and resists the penetration of moisture. Metallized 

polyethyleneteraphthalate (MPET) and AN–26 are specific 

choices of films that aviation manufacturers have used as 

coverings. 

9
Based on in-service experience in the mid-1990s, FAA 

researchers began investigating the adequacy of the 

existing Bunsen burner flammability criteria for testing 

thermal acoustic insulation. Those tests alerted the FAA 

to the need for a new certification standard, but any such 

standard would have to be based on a test method capable 

of screening out materials considered too hazardous for 

future installation. 

While developing the new test standard, FAA fire researchers also established criteria to determine whether or not 

existing materials could safely remain in service. A review 

of the service history, and subjecting AN–26 to a variety 

of tests, revealed that even though the material met the 

standards in place at the time of original certification in 

1981, this type of insulation material could result in a fire 

when subjected to electrical arcing and sparks. In cooperation with industry, the FAA used the insulation blankets’ 

response to electrical arcing and spark testing as the 

basis for identifying the unsafe condition with MPET, and 

determined that these same safety criteria were applicable 

to AN–26. Additional research data have shown that 

contamination, such as dust, lint, grease, corrosion-inhibiting compounds, can increase susceptibility to ignition and 

flame propagation. As a result of this research, the FAA 

has proposed adopting the new airworthiness directive for 

certain Boeing transport category airplanes. The proposed 

AD would require replacing any insulation blanket constructed of polyethylene teraphthalate (PET) film, ORCON 

Orcofilm AN–26 with a new insulation blanket. 

Because of the large cost of removing AN26 (estimated to 

be 400 million dollars for the U.S. fleet), the FAA conducted 

additional work to evaluate alternate means of compliance 

for the proposed AD. Researchers have already evaluated 

a fire blocking cover and a spray-on fire retardant, and they 

will continue to conduct tests to ensure that any approved 

alternate means of compliance meets the intent of the 

proposed AD.

Developing New Fire Test Methods

In 2003, the FAA passed a new rule pertaining to the flammability of thermal acoustic insulation used in transport 

category aircraft. The rule established two new tests – the 

first measures a material’s capability to resist flame spread 

from a small ignition source, and the second determines 

the ability of a material to resist penetration or burn through 

from an external fuel fire. A radiant panel is required to 

conduct the flame spread test, while an oil-fired burner is 

used to simulate the external fire in the burnthrough test. 

Both of these tests are significantly better than the previous 

test method used to qualify insulation materials.

Although researchers have developed and refined these 

new tests over the past two years, many details still need 

to be addressed with regard to the conduct of these tests 

and the actual installation of insulation blankets in an 

aircraft. In terms of flame propagation, for example, many 

components of the blanket system, such as tape and “hook 

and loop” fasteners must also be tested since they are considered part of the blanket system and affect whether or not 

the material will propagate a fire. To ensure that all blanket 

components are properly tested, the FAA recently developed advisory circulars for both new test methods based 

on results from the latest research. The radiant panel 

advisory circular (AC 25.856-1) describes the test methodology and pass/fail criteria for evaluating the flammability 

of insulation blankets containing sub-components, such as 

thread, tape, and hook and loop. Tapes, for example, are 

used during initial production and also in making repairs to 

an in-service aircraft. Since it is not practical to test each 

possible configuration of tape and film/batting material, 

researchers have developed a simplified process using 

10 
strips of tape. The advisory circular also requires testing 

for structural damping materials. For example, although 

small aluminum sheets bonded directly to the airplane skin 

are not considered insulation, materials that include a layer 

of foam or other material sandwiched between the skin and 

thin aluminum sheets should be tested. 

The burnthrough advisory circular (AC 25.856-2) describes 

the appropriate methods of installing the insulation in an 

aircraft. Insulation materials can be classified into three 

basic categories: batting systems, barrier systems, and 

encapsulating systems. The advisory circular describes 

each system type and provides schematic examples of 

each in an appendix. In addition, it highlights critical installation areas, such as blanket overlap at frame members, 

horizontal blanket overlap, penetrations, and types of installation hardware. It includes a detailed test methodology 

for evaluating the burnthrough resistance of two horizontally overlapped blankets, and describes the appropriate 

test methodology for evaluating system performance in 

the event that an alternative approach is desired. This 

methodology includes a description of the test apparatus 

modifications necessary to fully evaluate any unconventional approach.

An electronic version of the radiant panel advisory circular 

can be found at http://www.airweb.faa.gov/rgl. When 

published, the burnthrough advisory circular will also be 

posted on this site.

Ensuring International Aircraft Fire 

and Cabin Safety Research 

Cooperation

The Cabin Safety Research Technical Group, comprised of 

representatives from the major aviation authorities throughout the world, including the FAA, sponsored the Fourth Triennial International Aircraft Fire and Cabin Safety Research 

Conference in Lisbon, Portugal, on November 15-18, 2004. 

The fourth in a series of triennial conferences to inform the 

aviation community about recent, ongoing, and planned 

research activities in aircraft fire and cabin safety, this is the 

only technical conference devoted exclusively to fire and 

cabin safety research in civil transport aircraft. Approximately 350 people attended the sessions on materials fire 

safety, systems fire safety, evacuation, crash dynamics, 

and operational issues.

The conference fire safety sessions focused on fuel tank 

inerting, fuel flammability, thermal acoustic insulation 

flammability, and hidden fire safety. Other presentations 

included halon replacement (halon production was banned 

because it is an ozone depleting agent), smoke and fire 

detectors (current cargo detectors exhibit very high false 

alarm rates), and ultra-fire resistant materials. Sessions on 

aircraft evacuation covered a broad range of research activities. A major concern is evacuation from the new, highcapacity Airbus 380, which will have an equal number of 

passengers on the upper and lower decks. An operational 

issues session focused on passenger performance and 

awareness. A crash dynamics session covered modeling 

and crash testing. Attendees discussed passenger protection, the development of neck injury criteria for occupants in 

side-facing seats, and simplifying the aircraft seat dynamic 

test requirements. 

To make further improvements in aircraft fire and cabin 

safety, it is essential that stakeholders work together to 

seek practical and cost effective solutions. Information 

on the Cabin Safety Research Technical Group and the 

proceedings of all four conferences is available on-line at 

www.fire.tc.faa.gov.

11
Improving Aircraft Rescue and Fire 

Fighting

For over 13 years, FAA Aircraft Rescue and Fire Fighting 

researchers have relied on their High Performance Research Vehicle, an Emergency One Titan 4x4 fire fighting 

vehicle built and procured in 1992, to achieve significant 

safety advances. For example, under an Interagency 

Agreement between the FAA and the U.S. Air Force Research Laboratory, researchers developed fire and rescue 

innovations, including: the Driver’s Enhanced Vision 

System; the SnozzleTM High Reach Extendible Turret; High 

Reach Extendible Turrets with aircraft skin penetrating devices; the RhinoTM multi position high performance bumper 

turret; vehicle suspension enhancements; and the lateral 

G-force indicator for vehicle stability.

With the upcoming introduction of the new Airbus 380 aircraft in 2006, researchers anticipate the need for extensive 

live fire testing to develop standards for fire protection for 

the new aircraft, which will carry twice the number of passengers and twice the amount of fuel as most current passenger jets. The size of the new large aircraft and the need 

for more sophisticated test and development methods led 

the FAA to acquire a new state-of-the-art research vehicle.

With final specifications developed by FAA researchers, 

the new aircraft rescue and fire fighting vehicle is significantly larger than the older model with room for up to 6,000 

pounds of additional installed equipment, such as the next 

generation elevated boom. It has a water tank capacity 

of 2,500 gallons, dual foam tanks to carry two fire fighting 

agents, and an electronic foam proportioning system for 

better control of foam injection and better monitoring of the 

tracking agent used in testing. The vehicle also carries two 

complementary agents, Halotron and dry chemical. For optimum vehicle handling and tire wear, the vehicle has rear 

wheel steering capabilities.

In early August 2005, researchers conducted pre-delivery 

testing and inspection at the Oshkosh Truck Corporation’s 

Test and Development Labs. There they put the vehicle 

through all testing procedures specified for prototype vehicle designs in FAA Advisory Circular 150/5220-10C, “Guide 

Specification for Water/Foam Aircraft Rescue and Fire 

Fighting Vehicles.” This series of tests included both static 

and dynamic testing of the vehicle’s stability, acceleration, 

braking, steering, and pump, and roll capabilities. The new 

vehicle met all criteria and the FAA accepted it for delivery.

Creating the North American Bird 

Strike Advisory System Strategic 

Plan

Bird strikes continue to represent a significant safety risk to 

all aircraft. On the civilian side, over 6,000 bird strikes are 

now reported annually to the FAA National Wildlife Strike 

Database. Because they also represent a similar risk to 

military aircraft and international air traffic, the FAA, U.S. Air 

Force, and Transport Canada have joined forces to develop 

a North American Bird Strike Advisory System. When fully 

operational, the North American Bird Strike Advisory System, integrating state-of-the-art technologies such as radar 

detection and the use of Geographic Information Systems, 

will provide on-line advisories to prevent bird strikes. 

12 

Airport Technology
As the first step towards realizing this system, the three 

agencies have a drafted a strategic plan that highlights 

the many advantages of an integrated and consolidated 

bird strike advisory system. One such advantage is the 

improvement in the accuracy and fidelity of bird avoidance 

information provided to users in the aviation community. 

Another advantage of the proposed system is the use of 

data from new and existing radar and other systems to 

enhance bird activity reporting. A key element of the plan is 

the development of a robust communications infrastructure 

and network to enhance the timeliness and scope of bird 

advisory information.

This draft Strategic Plan is the initial step in a process of 

consolidating and integrating the various United States and 

Canadian civil and military efforts to develop and implement a North American Bird Strike Advisory System. When 

implemented, the plan will represent a critical first step 

leading to the realization of a North American Bird Strike 

Advisory System that will help protect aviators and aircraft 

from the deadly and costly effects of bird hazards.

Testing the Ability of Radars to 

Detect Foreign Object Debris

Foreign object debris (FOD) is defined as any substance 

alien to the vehicle or system that can potentially cause 

damage. FOD can result from the manufacture or maintenance of aircraft and from the loss of parts from aircraft, 

pavement cracking, wildlife, ice and salt accumulation, and 

construction debris. The critical need for FOD detection 

and removal was clearly demonstrated in the loss of the 

Concorde in 2000. 

To enhance airport safety, FAA researchers evaluated an 

experimental radar for the detection of FOD on runways. 

As part of the evaluation, they conducted tests over a twoweek period at New York’s John F. Kennedy International 

Airport in January 2005 to assess the radar’s ability to 

detect FOD, to recognize FOD amongst other items, and 

to precisely locate FOD on a runway. During the tests, 

researchers placed FOD items on the runways at locations, 

and recorded known placement locations using Global 

Positioning System (GPS) linked to a Geographic Information System (GIS). Radar return data was subsequently 

entered in the GIS system. The GIS system allowed for 

exact comparisons between known placed FOD items and 

radar processed FOD target returns.

These preliminary tests proved the potential of the radar to 

detect and locate FOD in clear dry weather and winter like 

conditions. Additional tests are planned to evaluate the 

performance of the radar under wet weather conditions.

The analysis of the tests and a preliminary evaluation of 

the radar, Evaluation of the Tarsier FOD Detection Radar, 

will soon be published and made available at http://www.

airtech.tc.faa.gov/safety/downloads/.

Developing Obstruction Lighting 

Standards for Wind Turbine Farms

As a result of a U.S. Department of Energy mandate that 

renewable energy sources provide six percent of the 

nation’s electricity by the year 2020, wind turbines are now 

being used in 32 of the 50 states in U.S., with predictions 

that turbines will soon be operating in all 50 states. This 

renewed interest in wind energy has resulted in new, large 

turbines capable of generating large amounts of energy. A 

single turbine, 442 feet tall from the tip of the blade to the 

ground, generates well over 5-million kilowatt-hours per 

year, enough to power more than 500 households. Some 

sites already in operation have over 200 turbines spread 

over 20 miles on top of mountain ranges.

 

Because of the size and number of these turbines, the FAA 

considers them air navigation obstructions. For anything 

over 200 feet high, Federal Air Regulations require these 

obstructions to air traffic be illuminated with the appropriate FAA approved flashing red, flashing white, or steady 

burning red light lighting. Although FAA Advisory Circular 

70/7460-1K, Obstruction Lighting and Marking, includes 

some provisions for lighting or marking a single wind turbine, it does not provide guidance for lighting a large group, 

or farm, of wind turbines. 

FAA researchers recently undertook an effort to develop 

obstruction lighting standards for wind turbine farms that 

would ensure pilots could easily see, identify, and avoid 

turbines and to minimize any effects of those lights on the 

surrounding community or wildlife. After an initial investigation of eleven wind turbine farms, researchers documented 

current light installation, how those lights appeared from 

the air during both daytime and nighttime conditions, and 

how the surrounding community perceived the lights. They 

documented their findings and recommended that obstruc

13
tions in close proximity to each other, as in a tower, bridge, 

or even wind turbine sites, should be treated as though 

they are one large obstruction. The recommended flashing 

lighting pattern would warn pilots that the obstruction was a 

single, very large structure that should be avoided. 

To validate these recommendations, the FAA established a 

test-site in Lawton, Oklahoma, with 43 wind turbines situated along a mesa in two predominant rows. In the lighting 

plan used for the test site, only 14 turbines were lit, versus 

the 26 that would have been required under the current 

guidance. Researchers conducted test flights, and through 

repeated evaluations confirmed that the proposed lighting 

configuration provided sufficient guidance to approaching 

aircraft. Researchers will publish the results of this evaluation in an FAA technical note, which will recommend new 

lighting standards for illuminating wind turbine farms as 

obstructions.

Alternating Yellow/Green Taxiway 

Centerline Lights to Enhance 

Runway Safety

FAA Advisory Circular (AC 150/5340-30), “Design and 

Installation Details for Airport Visual Aids,” provides airports 

with guidance for lighting exit taxiways with color-coded 

alternating yellow and green fixtures to warn pilots and 

vehicle drivers that they are within the runway environment. 

Upon suggestions from industry, FAA researchers examined the feasibility of changing from the existing concept of 

alternating yellow and green taxiway centerline lights -to, 

using the same color coding in the reverse direction as a 

warning that one is approaching to the runway environment 

from an intersecting taxiway. A lighting configuration such 

as this could act as an enhancement to the hold position 

area, helping to reduce runway incursions. It could be applied to any airport with existing taxiway centerline fixtures 

with minimum cost. 

To study this theory, researchers temporarily constructed a 

curved taxiway entrance lighting configuration, using standard FAA approved taxiway lighting fixtures, at the FAA’s 

William J. Hughes Technical Center. The simulated taxiway 

lighting configuration included the following characteristics:

• A lead-in segment of solid green colored centerline lights 

for a distance of 200 feet prior to the hold line location 

(the beginning of the runway environment).

• A continuing segment of alternating yellow and green 

taxiway lights along the straight and curved section of the 

taxiway/runway entrance to the point of tangency with the 

runway centerline.

• All spacing and alignment was in accordance with the 

appropriate FAA Advisory Circular.

• All fixtures were standard FAA approved L-852 taxiway 

lights, with standard lamps and filters. 

Those helping to test the configuration viewed the lighting 

configuration under the existing weather and ambient 

light conditions. Individual subjects then drove in ground 

vehicles, at typical aircraft taxi speeds, through the display. 

They stopped the vehicle at the simulated hold position, 

as though waiting for a clearance, and then drove along 

the curved, color-coded taxiway lights. From this study, 

researchers proved that the concept of illuminating the 

runway environment area with alternating yellow and green 

14 
centerline lights would be a cost-efficient way to improve 

safety at those airports that have existing taxiway centerline lights. 

Improving Aircraft Landing Lights 

FAA researchers investigated the potential safety advantages of standardizing aircraft landing lights in the airport 

environment. Specifically, they explored the procedural 

use of landing lights to let other pilots know which aircraft 

had clearance to depart. Thirty-two pilots participated in 

the study as either the Captain or First Officer of a Boeing 

747-400 simulator crew. Each crew flew either a set of 16 

scenarios in an environment with a standardized use of 

landing lights or scenarios using current practices. In some 

of the scenarios, a rogue aircraft made an error that caused 

a runway incursion that could have resulted in an accident 

if not detected by the subject crews. 

The research team conducted multidimensional measures 

of runway incursion severity and situation awareness after 

each scenario. In general, the pattern of results suggest 

that standardizing the use of aircraft landing lights to 

indicate that aircraft were cleared to depart prevented or 

reduced the severity of runway incursions or accidents 

and increased pilot situational awareness. Further studies 

are recommended to determine the effects of other factors 

such as consistency, conspicuity, and the effects of the 

message on other human system elements. Evaluating 

alternatives such as pulse lighting and the potential value 

of cues to air traffic control may reveal additional benefits.

Evaluating Runway Status Lights

The Runway Status Lights system consists of an array of 

lights called Runway Entrance Lights placed at runway/taxiway intersections to warn pilots and vehicle operators that 

a runway is unsafe to enter. Additional lights called take-off 

hold lights are being evaluated. These lights are placed on 

the runway from the departure positions and hold location and inform pilots that is unsafe to begin a departure. 

The Runway Status Lights System works in conjunction 

with ASDE-X, ASDE-3, ASR-9, and AMASS systems as 

part of a layered defense against surface accidents. The 

operational evaluation of the Runway Entrance Lights at 

Dallas Fort Worth Airport has been expanded to include 

the evaluation of the take-off hold lights as well. The FAA is 

also planning to extend the evaluation to additional airports.

Preventing Runway Incursions

FAA researchers are evaluating the potential of inductive 

loop technology to improve runway safety and to monitor 

airport surface movement at the Gulfport-Biloxi airport. 

The Runway Obstruction Warning System is based on 

technology used worldwide to control the flow of vehicles at 

traffic lights. It consists of a network of sensors embedded 

in/near runways and taxiways that can be configured to be 

monitored in the tower and/or control runway lights visible 

to flight crews.

As a result of demonstrations conducted at the GulfportBiloxi airport, researchers conducted a system engineering 

feasibility study to identify the specific functional and implementation changes required to transition from the prototype 

runway obstruction warning system to a national airspace 

system-compatible technology insertion candidate. Initial 

indications from the study show that such a system may be 

effective in the tower environment. 

Researchers demonstrated a redesigned system in July 

2005. Analysis of the demonstration results indicates 

the new prototype works better, but still has a number of 

anomalies. Planning and activities are underway to implement a number of recommendations from the study, and 

develop solutions for the anomalies, and recover from the 

effects of Hurricane Katrina.

15
Conducting Rigid Pavement FullScale Traffic Tests

Traffic tests involving full-scale simulated aircraft gear loads 

are essential to developing the airport pavement thickness 

design procedures for the next generation of heavy civil 

transport aircraft. The FAA National Airport Pavement 

Test Facility is the world’s only facility capable of performing controlled, full-scale traffic tests to failure on airport 

pavements subjected to realistic gear loads. In December 

2004, FAA researchers successfully completed a series of 

traffic tests on three rigid (concrete) pavement test items, 

designated as CC2 (for Construction Cycle 2).

All three test items included a 12-inch thick concrete 

surface, consisting of 15 x 15 foot slabs joined by dowels in both directions. The items had different structural 

designs to compare the performance of different foundation 

types. The three items included: a conventional structure, 

with the concrete slab supported by a crushed aggregate 

subbase; a concrete slab supported directly on the clay 

subgrade (no base); and a stabilized (econocrete) base 

between the concrete slabs and the crushed aggregate 

subbase. Researchers subjected the test items to two 

lanes of repeated traffic, with the facility’s load carriages 

programmed to simulate the normal lateral distribution of 

traffic (wander) on an airport taxiway. Except on one test 

item, the north load carriage applied a six-wheel gear load 

(three dual axles), similar to a Boeing 777, while the south 

carriage applied a 4-wheel gear. On one test item, both 

lanes received 4-wheel traffic, with different wander patterns. In all cases, the per-tire load was 55,000 pounds.

Researchers monitored the pavement test items for the 

onset and progress of cracks, which are an indicator 

of pavement performance. They conducted pavement 

performance monitoring at four levels: visual surveys using 

standard field inspection procedures; nondestructive testing using heavy-weight deflectometers and other devices; 

destructive testing of core samples; and embedded sensor 

monitoring. The research team used in-situ strain gages 

to detect the formation of cracks before they became visible from the surface. They recorded pavement condition 

using the Structural Condition Index (SCI), an index of rigid 

pavement performance, which varies between 0 and 100, 

and depends on the number, type and severity of observed 

cracks and other distresses. A SCI value of zero corresponds to complete loss of structural integrity. 

The total number of load passes varied by test item, from 

5,400 to 31,000 passes. Longitudinal cracks began to 

appear on the outer slabs of the test items after several 

hundred passes. Researchers continued trafficking the test 

items until full structural failure, characterized by extensive 

cracking, and significant loss of bearing capacity, occurred. 

Analysis of the test data has already yielded a number of 

significant conclusions. For example, the current design 

model assumes that the deterioration of SCI is a simple 

logarithmic function of traffic. The CC2 tests demonstrated 

that this relationship is valid for stabilized base as well 

as conventional structures. Furthermore, tests on three 

different supports (conventional, slab on grade, stabilized 

base) confirmed that the quality of the base has a specific, 

quantifiable effect on the durability of the pavement after 

the initial crack forms. This data, in combination with data 

from earlier full-scale tests, is being used to update the 

FAA’s thickness design standards for concrete pavements.

Evaluating Ultra-Thin Whitetopping 

for General Aviation Airport 

Pavements 

The FAA allows conventional concrete overlays with a 

minimum thickness of six inches to serve aircraft between 

12,500 and 30,000 lbs. and five inches for aircraft weighing less than 12,500 lbs. Thinner concrete overlay slabs 

(known as ultra-thin whitetopping or UTW) could theo16 
retically be justified for smaller aircraft on the basis of a 

structural analysis, if there is a strong and permanent bond 

between the new concrete overlay and the existing asphalt 

surface. UTW has been used extensively to rehabilitate 

highway pavements since the 1970s, but has only been 

used at three airports in the United States: Savannah-Hardin County, Tennessee; New Smyrna Beach, Florida; and 

Spirit of St. Louis Airport, Missouri. 

To assess the viability of using UTW for general aviation 

airport pavement rehabilitation, the FAA funded the Innovative Pavement Research Foundation to conduct a research 

project called, “Innovative Rehabilitation of Pavement for 

Light Load Aircraft.” The Innovative Pavement Research 

Foundation is a nonprofit research foundation sponsored 

by the American Concrete Pavement Association and Portland Cement Association to conduct research to improve 

the design, construction, and maintenance of concrete airport pavements. The project consisted of a field evaluation 

and a laboratory study. For the field evaluation, researchers studied the three general aviation airports currently using UTW. The airport field survey identified some locations 

where heavy loads (e.g., from fuel trucks) had apparently 

led to debonding and cracking in the UTW area.

For the laboratory work, researchers evaluated the 

concrete-asphalt bond. That bond, if properly constructed, 

should survive accelerated cycles of freeze/thaw and wet/

dry, simulating what a pavement might experience in the 

field. Failure of the bond, however, due to poor construction practices or to environmental cycling over time, could 

lead to loosening of concrete pieces and create a foreign 

object debris risk. Results of the laboratory testing proved 

somewhat surprising. Neither the freeze/thaw nor the 

wet/dry exposure cycles caused significant deterioration in 

the UTW bond, and researchers described the bond retention at the concrete/asphalt interface as excellent. The 

tests, however, did identify a potential failure location in the 

surface of the asphalt layer, which could be a concern if 

overlaying asphalt of unknown quality. 

A final report of this study is available on-line at http://iprf.

org/products/IPRF-01-G-002-3-Final%20Report.pdf.

 

Creating the Airport Cooperative 

Research Program (ACRP)

In September 2005, the Secretary of Transportation signed 

a Memorandum of Agreement implementing the ACRP. 

The ACRP is sponsored by the FAA , acting through its 

Transportation Research Board (TRB), and managed by 

the National Academies. Congress appropriated $3 million 

in FY 2005 and $10 million in FY 2006 to the FAA for ACRP 

research projects.

The ACRP will carry out applied research on problems 

that are shared by airport operating agencies and are not 

being adequately addressed by existing federal research 

programs. The ACRP will undertake research and other 

technical activities in a variety of airport subject areas 

including design, construction, maintenance, operations, 

safety, security, policy, planning, human resources, and 

administration.

The primary participants in the ACRP include representation from the FAA, airport operating agencies, Airports 

Council International - North America (ACI-NA), the American Association of Airport Executives (AAAE), the National 

Association of State Aviation Officials (NASAO), the Air 

Transport Association (ATA), and TRB. 

The ACRP will produce a series of research reports for 

use by airport operators, local agencies, FAA, and other 

interested parties.

17
Demonstrating the Small Aircraft 

Transportation System Concept

FAA and NASA researchers, along with local airports and 

aviation authorities, concluded the five-year public/private 

research program on the Small Aircraft Transportation 

System (SATS). SATS is a collaborative research effort 

between NASA, FAA, and industry focused on increasing 

public access and mobility within the national airspace 

system. It is designed to facilitate transportation between 

small general aviation airports using small aircraft as an 

alternative to traditional airline travel.

Project participants successfully concluded a proof of concept demonstration of four operating capabilities in Danville, Virginia, in June 2005. The four capabilities included: 

higher volume operations at nontowered, nonradar airports; 

lower landing minima; single pilot performance; and 

integration of SATS operations into the national airspace 

system. When implemented, these operating capabilities 

will enable point to point, on demand travel between more 

than 5,400 existing small airports. 

Testing the Surface Traffic 

Management System

FAA and NASA researchers successfully completed the 

initial surface traffic management system research at the 

Memphis International Airport, demonstrating that this 

technology could safely increase airport capacity and 

efficiency using traffic management technologies. The 

surface management system is a decision support tool that 

will help controllers, traffic managers, and airspace system 

users manage the movements of aircraft on the surface of 

busy airports, improving capacity, efficiency, and flexibility. 

The system presents a real-time map display of the airport 

layout, aircraft, taxiways, runways and gates. With the click 

of a mouse, individual aircraft can be targeted and pertinent 

information about the flight’s arrival and departure appears 

on a computer screen. The technology predicts arrival 

time, touchdown, and taxi time to the gate.

After successful tests, Memphis International Airport is 

now operating the system for the FAA under a cooperative 

research and development agreement. FAA and NASA 

Air Traffic 

Management

18 
researchers continue to refine surface management system 

functions, including developing more efficient traffic flow 

management functions. As part of a continuing surface 

investigation effort, FAA researchers installed the system 

at Louisville, Kentucky, for use by UPS ramp controllers. 

The surface traffic management system currently provides 

UPS ramp controllers with a tactical display of aircraft, 

both on the surface and in the vicinity of the airport, and 

serves UPS as a vital tool in efficient ramp management 

for unloading, loading, and refueling. Enhancements from 

the second phase of research will be installed and tested at 

airports other than those already using the SMS. 

Developing the Traffic Management 

Advisor Multi-Center

The Traffic Management Advisory-Multi-Center (TMA-MC) 

system is an extension of the Single-Center TMA Decision 

Support Tool in current use at more than half of the FAA Air 

Route Traffic Control Centers. The FAA and NASA are developing TMA-MC to enable time-based scheduling of arrivals to airports in the complex airspace of the Northeastern 

United States. High traffic congestion, multiple merging 

routes, narrow airspace sectors, and terminal airspace fed 

by more than one Center characterize this airspace.

During FY 2005 researchers conducted an operational 

field evaluation of the system to assess potential benefits. 

Researchers assessed the system’s performance using 

metrics that compared the operational delay at Philadelphia 

Airport while using TMA-MC against the delay under similar 

weather and demand conditions without the tool. TMA-MC 

proved successful in that operational trial – average delays 

at Philadelphia were significantly lower using TMA-MC as 

compared with the average delay in each of six non-TMAMC control periods.

Evaluating the Digital Airport Map 

Database

During FY 2005, the certification process was begun and 

work was done on the digital airport map creation and 

maintenance process. The production team is currently 

awaiting an investment decision by the FAA to continue reprocessing the original 82 maps and expand the database. 

This database is intended to be used in certified avionics 

applications, such as surface moving maps to enhance 

pilot and vehicle operator situational awareness.

19
Improving Aviation Weather 

Forecasts

One of the key ways to improve aviation safety and 

capacity is to provide better forecasts of aviation weather 

phenomena. The FAA Aviation Weather Research 

Program has sizeable research efforts in forecasting 

meteorological phenomena that pose problems for aviation, 

including: convective weather; aircraft icing (both in-flight 

and on ground); low ceiling and visibility oceanic weather; 

and turbulence. Recognizing that data quality can also be 

affected by the nature and quality of the meteorological 

sensors, the FAA also invests in new sensor development 

and radar technology. Scientists and engineers from the 

National Center for Atmospheric Research, Massachusetts 

Institute of Technology Lincoln Laboratory, and the National 

Oceanic and Atmospheric Administration (NOAA) Global 

Systems Division, National Severe Storms Laboratory, and 

Aviation Weather Center collaborate to provide the best 

technical solutions for aviation. 

The Aviation Weather Research Program makes use of 

several government platforms to deliver its products to end 

users, via experimental prototypes or via formal government technology transfer efforts. These platforms include:

• FAA Integrated Terminal Weather System (ITWS), which 

operates four prototypes demonstrating new products, 

and 11 operational systems at key terminals around the 

country. ITWS dedicated access is available to the towers, terminal radar approach control facilities, air route 

traffic control centers, and the Air Traffic Control System 

Command Center.

• FAA Enroute Weather and Radar Processor (WARP) 

system, present in all enroute air traffic control facilities, 

provides weather products for the enroute controllers’ 

displays. 

• Aviation Digital Data Service (ADDS), specifically developed by the FAA to provide public access to aviation 

weather data and products, also serves as an approved 

site for general aviation pilot weather briefings. 

Providing Weather Information on 

the Internet

For public dissemination of weather information, the FAA 

developed the Aviation Digital Data Service, available 

24-hours a day on the Internet (http://adds.aviationweather.

gov). Operated by the National Weather Service, this aviation information allows pilots, airline dispatchers, and other 

aviation users easy access to up-to-date weather data 

and products in user-friendly graphical and text formats. 

By providing pilots and dispatchers easy access to the forecast weather conditions, the Aviation Digital Data Service 

facilitates flight planning and minimizes the time required to 

change the route of flight when needed.

The Aviation Digital Data Service integrates existing tools, 

such as the current icing potential, forecast icing potential, 

graphical turbulence guidance, and the national convective weather forecast, to bring text, digital and graphical 

analyses, and observations of the latest weather developments to a variety of users. An important feature of the 

Aviation Digital Data Service is the flight path tool, which 

employs user-friendly graphics to display thunderstorms, 

Aviation Weather

20 
icing, turbulence, and other aviation weather hazards, for 

all flight altitudes, along a chosen route of flight selected by 

the user. 

FAA-funded researchers recently added new functionality 

to the flight path tool, making it even easier for users to 

plan routes to avoid dangerous weather. The original flight 

path tool gained popularity because it displayed complex 

three-dimensional gridded data, like icing or turbulence, 

with the observed and forecasted weather conditions 

provided in pilot briefings and other traditionally-used observation and forecast reports. Using the on-line program, 

a user can “click” on a route of flight within the continental 

U.S. and view these products in the vertical dimension 

along that route.

Forecasting Turbulence

Turbulence accounts for 65 percent of all weather-related 

injuries, while only 35 percent of turbulence is forecasted. 

Because observations and forecasts are not accurate 

enough to pinpoint the location, time, and intensity of 

turbulence, FAA-funded researchers created the Graphical Turbulence Guidance product. This tool produces 

easy-to-interpret depictions of turbulence. It is available 

on the web-based Aviation Digital Data System, allowing 

anyone with an Internet connection access to the display, 

which shows relative turbulence intensities at user-selected 

altitudes. 

Using input from several numerical weather prediction 

models, the Graphical Turbulence Guidance tool refines 

turbulence assessments by comparing the models with current pilot reports of turbulence. It produces turbulence forecasts out to twelve hours and clear-air turbulence forecasts 

for altitudes above 20,000 feet. Recently, a new Graphical 

Turbulence Guidance product for altitudes above 10,000 

feet received FAA and National Weather Service endorsement through the Aviation Weather Technology Transfer 

Board. With the Board’s endorsement, researchers 

entered into the final phase of research needed to advance 

the product to operational status. During this experimental 

research phase, users are allowed to view the product 

(versus a limited controlled group in the early research 

phase) and provide feedback, which the researchers use 

to refine and validate the product before requesting an 

operational decision from the Board. This is one more step 

toward a fully-developed, advanced Graphical Turbulence 

Guidance tool, which will provide forecasts for all altitudes 

and will have the capability to forecast mountain-wave and 

convectively-induced (regions involving thunderstorm activity) turbulence. 

To meet the short-term need of pilots to obtain sufficient 

warning of turbulence ahead to alert passengers and crew 

or to take evasive action, FAA researchers are developing 

a turbulence detection tool. The research team conducted 

a real-time regional demonstration last summer that 

combined the outputs of 16 NEXRAD radars located in the 

upper Midwest region. Researchers created a three-dimensional image (mosaic) of detected turbulent conditions 

from these combined data sets. During the test, a commercial vendor sent the image, including a customized map of 

the flight region, via an uplink to the cockpit of the demonstration partner’s aircraft. The detection product produced 

turbulence intensities in the form of a metric, the eddy 

dissipation rate. The eddy dissipation rate is a measure of 

the actual atmospheric conditions since it does not include 

pilot induced actions or the aircraft’s response. This metric, 

combined with the radar information, provides a 15-minute look ahead of in-cloud aviation hazards, emphasizing 

convectively-induced turbulence. Once the turbulence 

detection product is approved for operational use, the FAA 

plans to install it on all operational NEXRADs (anticipated 

in FY 2008). The eddy dissipation rate data could then be 

incorporated into existing aviation decision support systems 

to provide convectively-induced turbulence nowcasts to the 

aviation community.

Ensuring Safety in Winter Weather

The Weather Support to Decision Making (WSDM) System, 

developed with FAA funding, is currently operational at the 

Minneapolis-St. Paul International Airport as well as Denver 

International Airport. The system uses Doppler radar, 

surface weather data, and snow gauges to determine precipitation type, temperature, wind speed and direction, and 

the liquid water equivalent of snow. The system produces 

real time, short-term forecasts in the terminal area to support aircraft deicing and terminal management of runways 

during winter storm conditions. In a recent upgrade to the 

system, researchers completed development of a freezing drizzle detection product. Freezing drizzle conditions 

21
experienced at Denver International Airport during the past 

two winters resulted in more than two million dollars of 

engine damage as well as additional costs due to damaged 

aircraft taken out of service. With the upgrade installed, the 

WSDM system correctly diagnosed a freezing drizzle event 

this past January at the Denver airport. Since implementing the drizzle detection product and changing engine runup procedures (sheds ice buildup on engine fan blades), 

the airlines have reported no further engine damage as a 

result of freezing drizzle.

Forecasting Oceanic Weather

Lack of data on oceanic routes results in unnecessary 

rerouting or encounters with hazardous weather. To address this need, FAA-funded researchers developed an 

Oceanic Cloud Top Height product to provide pilots with an 

automated graphical display showing areas of convection 

relative to the aircraft’s flight path and altitude. Having 

this information allows pilots to avoid dangerous convection and turbulence conditions that occur around clouds 

along their oceanic routes. In May, after providing technical 

presentations to the joint FAA/National Weather Service 

Aviation Weather Technology Transfer Board, the Board 

approved the product to enter the experimental phase of 

research. The team will use this phase to refine the product prior to seeking an operational decision. The team also 

demonstrated the feasibility of using an automated uplink of 

this product to select commercial aircraft this year.

Improving Safety with National 

Ceiling & Visibility Tools

Low cloud ceilings and poor visibility conditions are safety 

hazards for all types of aviation. In fact, in the continental 

United States, 72 percent of ceiling and visibility related 

accidents result in fatalities. To mitigate these types of 

accidents, FAA-funded researchers created a National 

Ceiling and Visibility Analysis product that provides users in 

the lower 48 states an automated graphical display showing current ceiling, visibility, and flight category conditions 

along their route of flight. The joint FAA/National Weather 

Service Aviation Weather Technology Transfer Board 

has approved this product for experimental use. During 

the experimental stage, all users can view the product 

and provide feedback on its performance, allowing the 

researchers to make necessary refinements before seeking 

the product’s operational release from the Aviation Weather 

Technology Transfer Board.

Ceiling and visibility conditions are also a major concern 

within Alaska. Data indicate that 55 percent of ceiling and 

visibility-related Alaskan accidents result in fatalities. The 

FAA continues to make progress on the National Ceiling 

and Visibility Alaskan Analysis product, which is now in the 

testing phase of its research. In addition, a companion 

product, the National Ceiling and Visibility Alaska Forecast 

product, has received approval from FAA and the National 

Weather Service to enter the testing phase of research. 

The test phase means that limited users can see the 

product and provide input into the development process. 

When fully developed, the Alaskan forecast product will 

provide users with an automated graphic display containing 

forecasts from 1 to 12 hours of ceiling, visibility, and flight 

category conditions.

22 
Mitigating the Effects of Convective 

Weather

The FAA has a multifaceted research program designed 

to mitigate convective weather delays and improve safety 

near thunderstorms. The largest research project is geared 

toward providing aviation-oriented convective weather 

depictions and forecasts on the tactical (0-2 hour) time 

scales. Multiple radar data sources, satellite imagery, surface observations and numerical model data are combined 

using fuzzy logic techniques to produce high resolution 

forecasts. Thunderstorm growth and decay trends are 

provided as a product overlay and incorporated, along with 

initiation evidence, internally into the forecast storm evolution. A smaller but very significant research component is 

geared toward improving strategic (2-6 hour) forecasts of 

convective weather. The fuzzy logic forecast technology is 

coupled with numerical weather predictions and climatology 

to produce a blended 0-6 hour forecast. Improving these 

probabilistic strategic forecasts is crucial to enabling more 

effective traffic flow planning. Experimental tools are made 

available on FAA operational weather and air traffic control 

systems and the National Weather Service-operated Aviation Digital Data Service, allowing FAA air traffic specialists, 

airline dispatchers, and pilots to use experimental products 

and provide feedback leads to critical tool refinements. In 

the future, researchers hope to integrate these new tools 

into the automated traffic flow management decision support systems and cockpit data link technology. 

In fiscal year 2005, researchers demonstrated several capabilities, including a 0-2 hour Echo Tops Forecast product, 

which improves situational awareness between the terminal 

radar approach control facility and en route managers. It 

allows them to keep routes open longer, reroute traffic earlier/close impacted routes sooner, thereby minimizing cost 

and impact to airlines. They also extended the convective forecast out to 6 hours and introduced a probabilistic 

forecasting capability, requested by the operational user 

community. In addition they demonstrated techniques to 

forecast new growth of thunderstorms, the growth of which 

can greatly disrupt traffic flow and capacity. 

Researchers conducted a demonstration in the Chicago 

area. As a result, researchers found a new means 

of detecting surface effects on convection. A second 

demonstration occurred in the Dallas-Fort. Worth region 

where a meteorologist at the Center Weather Service unit 

(a position within the air route traffic control center) helped 

test the 1-hour automated forecast of storm initiation. The 

meteorologist supplied value-added enhancements to the 

automated output.

Avoiding In-flight Icing Conditions

The formation of even a thin coat of ice on an aircraft 

surface can seriously impact an airplane’s ability to fly by 

increasing drag, decreasing lift, and increasing aircraft 

weight. In many cases, the build-up of ice is so rapid that 

the pilot does not have enough time to take corrective action. National Transportation Safety Board records indicate 

that in-flight icing causes more than 25 accidents annually, 

with over half of these resulting in fatalities and destroyed 

aircraft. This equates to $100 million in injuries, fatalities, 

and aircraft damage each year. 

To address this problem, FAA researchers developed the 

Current and Forecast Icing Potential products to alert users 

to areas of in-flight icing, by displaying graphically the likelihood that icing will occur along their route of flight. The 

Aviation Weather Technology Transfer Board approved an 

upgrade to the Current Icing Potential product for operational use. The upgrade provides a more detailed look, at 

greater spatial resolution, of icing conditions. Users can 

now see the finer details of weather structure contributing 

23
to potentially hazardous icing conditions, providing a more 

accurate depiction of the icing hazard. This improvement 

allows pilots to devise flight plans that more effectively 

avoid these regions and thus enhances safety. 

Assessing Quality

Because verification is critical to providing reliable information for improved weather forecasts, FAA-sponsored researchers are developing verification techniques and tools 

that allow forecasters, and developers to generate and 

display statistical information in near real time. To enhance 

verification efforts, researchers are developing a Real-Time 

Verification System as a tool for assessing the quality of 

weather forecasts (http://www-ad.fsl.noaa.gov/fvb/rtvs/). 

The system is designed to provide a statistical baseline for 

weather forecasts and model-based guidance products, 

and to support real-time forecast operations, model-based 

algorithm development, and case study assessments. 

More importantly, it provides verification of research and 

operational weather products in real time via the Internet. 

This allows an aviation decision-maker to know how well a 

product is performing. 

A flexible easy-to-use web-based graphical user interface 

allows quick data access. Users can compare various 

forecast lengths and issue times, over a user-defined time 

period and geographical area, for a variety of forecast 

models and algorithms. System users include aviation 

researchers, the National Weather Service’s Aviation 

Weather Center, the FAA Air Traffic Control System Command Center, the FAA/National Weather Service Aviation 

Weather Technology Transfer Board, and several airline 

dispatch centers. On June 30, researchers installed the 

system as a prototype at the National Weather Service 

Headquarters in Silver Spring, Maryland. This prototype 

is a major milestone in achieving full operational verification capability. It is anticipated that the system will be fully 

operational in early 2006.

Enhancing Weather Models

The Rapid Update Cycle is an operational weather 

prediction system comprised primarily of a numerical 

forecast model and an analysis system to initialize the 

model. Funded by the FAA, National Oceanic and 

Atmospheric Administration researchers developed the 

model to provide frequently-updated short-range weather 

forecasts.

24 
Researchers have now updated the model to provide 

higher resolution graphics and assimilation of additional 

weather information, including improved moisture analysis 

and improved cloud/precipitation physics, to increase 

forecast accuracy. Called RUC 13 because of its 13-

kilometer resolution, the model provides improved aviation 

and surface forecasts of interest to aviation as well as the 

general public. The RUC 13’s output is used as input for 

FAA-developed aviation-weather applications that produce 

weather forecasts. 

Testing the Phased Array Radar

FAA researchers, in partnership with the Department of 

Defense, Office of Naval Research, National Oceanic 

and Atmospheric Administration, National Severe 

Storms Laboratory, Oklahoma State Regents for Higher 

Education, University of Oklahoma School of Meteorology 

and Engineering, and Lockheed Martin, are conducting 

research and testing of the Phased Array Radar 

Technology to improve airport and aircraft tracking and 

weather information for civilian use. In fiscal year 2005, 

the Office of the Federal Coordinator for Meteorology 

established the Phased Array Radar Joint Action Group 

tasked with completing the “Federal Research and 

Development Needs and Priorities for Phased Array 

Radar.” The purpose of this document is to establish the 

need for multiagency research in phased array technology. 

Researchers installed the track processor at the National 

Weather Radar Testbed, located at the National Severe 

Storms Laboratory in Norman, Oklahoma, in September 

2005. The processor enables dual use capabilities 

– tracking aircraft while simultaneously gathering 

meteorological data.

The FAA also began a research project with the 

Massachusetts Institute of Technology Lincoln 

Laboratory to assess the feasibility of developing low 

cost transmit/receive modules. The studies showed that 

low cost modules are feasible, that the technology and 

manufacturing to support them is greater than anticipated, 

and that phased array radar technology is becoming 

affordable for civilian use. Additional studies are underway 

to develop a phased array system architecture.

25
Enhancing Flight Safety Systems

The FAA Office of Commercial Space Transportation 

completed a follow-on study to its earlier report on nontraditional flight safety systems. Conventional flight safety 

systems minimize the threat to public safety and property 

posed by a malfunctioning launch vehicle. Non-traditional 

versions include fully autonomous and semiautonomous 

systems that interface with pilots and/or ground controllers. 

Because the FAA anticipates the application of these methods to spacecraft safety and health monitoring systems 

in the near future, proper regulation of these systems is 

essential to maintaining a consistent level of safety at a 

variety of ranges and spaceports. 

In its earlier study, researchers developed a verification 

framework for the regulatory approval of nontraditional 

systems. In an effort to gauge the effectiveness of this 

methodology, researchers recently applied it to an autonomous flight safety system currently being developed and 

tested by NASA at its Wallops Flight Facility. Because this 

program is still evolving, researchers based their evaluation on early research data in combination with results from 

completed tests. The results and lessons learned during 

this trial yielded valuable initial insights into possible approaches to creating valid new regulations. 

Mitigating Radio Frequency 

Blackouts

During the critical reentry phase of flight, space vehicles 

can suffer severe degradation or total loss of voice and 

data communications because of high temperature 

plasmas. A study assessing the radio frequency blackout 

phenomena caused by plasma generation has been completed. It evaluates the known methods for mitigating this 

condition that might be applicable to prospective reentering 

commercial space vehicles. In particular, the methods 

demonstrate the ability to predict the ionized flow field to 

identify the altitude of blackout onset. 

Researchers studied four mitigation methods under active 

and passive classes. The passive methods, such as 

aerodynamic shaping and use of high frequencies, show 

the most potential. By avoiding a temporary loss of signal 

strength, these methods may make continued communications possible with reentering craft. They also may meet 

the cost effectiveness requirements imposed upon commercial reusable launch vehicles. Researchers will continue to identify specific frequency bands that are suitable 

for communications in the presence of plasma shielding.

26 

Commercial Space
Analyzing Debris Risk

The FAA often uses computer-based models to develop 

public casualty expectations associated with launch 

accidents. In addition, the FAA uses the model to help 

establish insurance requirements and liability limits. 

To ensure safety of commercial launches, FAA researchers 

tested how well the current computer model could calculate 

the hazards to victims inside of buildings struck by falling 

debris. During the tests, researchers compared results 

from the model with actual damage data from exploded 

inhabited buildings. Sources of the historical data included 

the Khobar Towers bombing, the World War II bombing 

of London, the Oklahoma City bombing, and the SCUD 

missile attacks on Israel. Researchers have completed 

the Khobar Towers data comparisons. The data suggest 

that the FAA model is not as conservative as some had 

suspected. Completion of the project, slated for early next 

year, should provide a better basis for predicting debris-related casualties resulting from launch accidents.

Identifying Weather Delays

Postponing or canceling a commercial launch directly 

affects operational costs, which often exceed millions 

of dollars. To better understand the effects of weather 

on Expendable Launch Vehicle launches, researchers 

looked at data from over 300 launches from 1988-2005 at 

the Eastern Range at Cape Canaveral, Florida, and the 

Western Range at Vandenberg Air Force Base, California. 

In addition, several launches from the Kodiak Launch Complex in Kodiak, Alaska, were reviewed to determine trends 

and predict problematic weather for future launch operations. They categorized data into weather delays or scrubs 

as a result of lightning launch commit criteria, range safety, 

or user weather constraints. When research is completed, 

the published results will help commercial launch operators make sound decisions regarding launch operations 

and planning. The outcome will highlight new methodologies and help identify additional studies to aid commercial 

operations in the future.

Evaluating Reconfigurable Control 

Allocations for Reusable Launch 

Vehicles

Control surface degradation or actuator failure may pose 

a significant safety threat to reusable launch vehicles. To 

enhance safety and reliability of these vehicles, the FAA 

initiated a study to evaluate advanced guidance and control 

methods to compensate for control surface damage or 

failure. In particular, researchers wanted to know if alternative actuators and a reconfigured adaptive control strategy 

might help improve the management of emergency situations. Such a system would modify the guidance laws in 

response to real-time equipment conditions, resulting in 

changes to flight control strategies.

Researchers found that the most desirable solution would 

be for the control algorithms to adapt to changing conditions using available control surfaces and other actuators. 

They developed the concept of an executive reconfiguration control scheme that is independent of the physical 

hardware layer. A critical aspect of the system would be 

the ability to distribute control responsibility among available actuators in a reconfigured mode with a new management strategy that would adjust the flight profile to reflect 

the modified goal. Such a hierarchical scheme has the 

advantage of being design and device independent and, 

therefore, applicable to all generic reusable launch vehicle 

physical equipment types. 

27
Developing a Suite of Analytical 

Tools

Because aviation noise and emissions are highly interrelated phenomena that must be understood and mitigated 

together, FAA and NASA researchers are developing an integrated suite of analytical tools, the Environmental Design 

Space (EDS), Aviation Environmental Design Tool (AEDT), 

and the Aviation environmental Portfolio Management Tool 

(APMT). Each tool in the suite provides a key component 

of a valuable integrated decision making capability. EDS 

generates performance and cost data on source noise and 

exhaust emissions. AEDT computes and identifies interrelationships between noise and various emissions at the 

local, regional, and global levels. APMT computes the economic impact and assesses the cost-benefit of mitigation 

strategies. Individually these tools provide critical data, but 

as an integrated set they can help government and industry 

undertake operations and projects that more effectively 

control aviation noise and emissions. The toolset also will 

help the aviation community educate the public about how 

aviation noise and emissions, in combination, affect local, 

regional, and global communities.

Last year, on behalf of the FAA and NASA, the National 

Research Council’s Transportation Research Board began 

an assessment of the proposed tool suite. The Board conducted three workshops to analyze the required capabilities of the new toolset, and assess existing tools and their 

integrated potential. The FAA and NASA used the input 

from those meetings to refine the conceptual foundation 

and formulate a comprehensive work plan. In March 2005, 

the agencies launched their full-fledged development effort. 

Member universities of the FAA/NASA/Transport Canadasponsored Partnership for Air Transportation Noise and 

Emissions Reduction (PARTNER) are developing the EDS 

and APMT modules. They completed version 0.0 of the 

EDS module and are now validating and refining it. They 

also completed comprehensive requirements and architecture studies for APMT and are now engaged in developing version 0.0. Led by Volpe National Transportation 

Systems Center, a team including the ATAC Corporation, 

CSSI, Inc., and Wyle Laboratories is developing the AEDT 

module. They have completed prototypes of that system’s 

components and are collaborating with the EDS and APMT 

development team to ensure the various modules function 

as an integrated tool suite.

Although this research and development work will last a 

decade, some capabilities will come on-line between 2006 

and 2009 – in time to influence the seventh and eighth 

meetings of the International Civil Aviation Organization’s 

(ICAO) Committee on Aviation Environmental Protection 

(CAEP). The integrated tools will help to inform regulatory 

decisions that have historically incurred $10 billion to implement in mitigation costs to government and industry. 

PARTNERing for Excellence 

The PARTNER Center of Excellence, sponsored by the 

FAA, NASA, and Transport Canada, and directed by the 

Massachusetts Institute of Technology (MIT) has seen considerable growth in its two-year history. PARTNER recently 

Environment & 

Energy

28 
welcomed York University of Toronto, Canada, and the 

Georgia Institute of Technology to its team – which, in addition to MIT, also includes Boise State University, Florida 

International University, the Pennsylvania State University, 

Purdue University, Stanford University, the University of 

Central Florida, and the University of Missouri – Rolla. The 

addition of York University reflects the Center’s goal to 

expand internationally and also supports a key element of 

the Center’s research strategy – to expand its capabilities 

in the area of climate change impacts from aviation. The 

addition of Georgia Tech reflects the growth in the Center’s 

activities in modeling.

In the past year, the Center also added two members to 

its Advisory Board: Airbus and Bombardier. The Advisory 

Board, comprising a broad range of stakeholders, serves 

as the principal point of contact for establishing collaborative research programs with industry and is the primary 

mechanism for ensuring that research is aligned with 

national and international needs. 

The FAA has identified six of the Center’s research efforts 

as “highly influential.” The Office of Management and Budget (OMB) requires the agency to give this designation to 

any research effort it considers to have a potential impact 

of more than $500 million in any one year on the public 

or private sectors, or if the work is novel, controversial, or 

precedent-setting. PARTNER research efforts – on climate 

impact of aviation, particulate matter and hazardous air 

pollutants, noise metrics, supersonic transport acceptability 

criteria, and monetization of aviation environmental impacts 

of aviation to inform policies and regulatory actions, both 

nationally and internationally – clearly meet these criteria. 

Once PARTNER research undergoes a formal peer review 

process, the FAA expects the research results to influence 

greatly the aviation enterprise and the general public. 

Studying Airport Encroachment and 

Land Use

A PARTNER researcher team, led by Purdue University 

and Florida International University, is researching issues 

of airport encroachment and land use. The Management 

and Airport Controls project is studying development 

around Denver International, Fort Lauderdale International, 

and Orlando-Sanford International airports. The team is 

working closely with airport administrators, civic leaders, 

and aviation organizations to collect data on the most 

prominent encroachment issues. Researchers are using 

census and image analyses from 1970 to 2000 to evaluate 

demographic trends and socioeconomic factors in areas 

adjacent to the study airports. The study will reveal trends 

and provide lists of indicators to predict where and why 

population expansion will occur and help to prevent its 

encroachment near airports. 

In the fall of 2006, the team will present a final report of its 

findings and recommendations to help inform future policy. 

This research has been given the OMB designation “influential,” as the findings are expected to have a clear and 

substantial impact on important public policies or private 

sector decisions of high public interest.

Furthering Knowledge Through 

Quiet Technology Demonstrator 2

The Agency continues to support research into new noise 

reduction technologies through participation in NASA’s 

Quiet Aircraft Technology Project. The goal of this program 

is to reduce perceived aircraft noise by 50 percent in 

10 years, using 1997 levels as the baseline. As part of 

this effort, FAA, NASA, and aerospace industry partners 

recently flight tested new, jointly developed noise reduction 

technologies. During the three-week flight test program, 

Quiet Technology Demonstrator 2, researchers used a 

Boeing 777 to validate the benefits of several new noise 

reduction technologies, including two improved chevron 

designs on the engine nacelle, and a cover that fits on the 

landing gear. 

Chevrons are scalloped or serrated edges already used on 

some newer jet engines. They modify the exhaust flow to 

reduce the jet noise levels. One improved chevron design 

includes asymmetrical scallops around the engine.

The new design tailors the chevrons to take into account 

the air flow and acoustic differences that occur when the 

engine is installed on the aircraft. Laboratory tests show 

the advanced chevron shape will reduce jet noise as much 

as four decibels during takeoff and when flying at cruise 

altitude. Results of the flight tests may lead to changes in 

aircraft configurations, future airplane engine and landing 

gear designs.

29
NASA research has shown that when landing, air rushing past a conventional landing gear is almost as loud as 

engine noise. To address this problem, the landing gear 

cover tested during the Quiet Technology Demonstrator 

2 flight test is a toboggan-like cover for the aircraft’s main 

landing gear. The cover streamlines the landing gear and 

makes it less noisy. The cover had previously been tested 

in a wind tunnel on a 26 percent scale model of the landing 

gear. The covered gear concept could reduce landing 

noise by another three decibels.

Mitigating Sonic Boom

The FAA and NASA have initiated a project, through PARTNER, to understand the impact of sonic boom phenomena. 

The project team is led by Pennsylvania State University 

and Purdue University. Its objectives are to assess applicability of existing noise metrics to sonic boom, determine 

annoyance associated with supersonic jets, and provide 

guidance for designing supersonic jets that will minimize 

the impact of sonic boom. 

This research project began in April 2005. The project 

team has surveyed existing sonic boom simulators to 

compare their abilities to duplicate sonic boom sounds and 

has begun to use the devices to assess human perceptions 

of the simulated sounds. 

The team is using a mobile Gulfstream simulator. Comparisons of the Gulfstream with the NASA Langley and 

Lockheed-Martin simulators and real booms are being 

conducted at NASA Langley Research Center in Hampton, Virginia, NASA Dryden Flight Research Center, near 

Palmdale, California, and at Lockheed-Martin Aeronautics 

in Palmdale, California. 

Once testing is completed, the researchers will evaluate 

the results from the three simulators against one another 

to compare the realistic and reproducible qualities of their 

output. Based on the findings from these tests, the project 

team will agree on requirements for sonic boom simulators. 

If they deem the realism in one or more of the simulators 

acceptable, the team will conduct subjective tests. Based 

on these tests, preliminary acceptance metrics would be 

defined by the end of 2006. This would guide development 

of a demonstration aircraft. 

The researchers are also studying representative atmospheric turbulence filter functions by means of glider and 

ground waveforms derived from the shaped sonic boom 

demonstrator field measurements. They performed the 

demonstrator flights using a modified F-5E aircraft with flattop front shock shaping only. The project’s industrial partners will collaborate in a detailed analysis of the waveforms 

collected in those studies to create waveforms, of a shaped 

boom design, that have been propagated through realistic 

atmospheric effects. This will help design aircraft that will 

take into account realistic sonic boom impact. 

Understanding Low Frequency 

Noise

Citizens ultimately determine when the noise associated 

with aviation is at an acceptable level. Researchers understand, however, that they need to determine a scientifically-based metric to assess the human impact of aircraft 

noise. In its search for such a metric, the FAA is funding 

the PARTNER Center of Excellence to study low frequency 

noise. The study encompasses many factors, including the 

noise source level and its spectrum, atmospheric propagation, the impact on homes in the form of noise, vibration 

and rattle, subjective perception and annoyance, and the 

ability of metric calculations to predict the physical and 

perceived impact. 

The researchers are exploring new ways to measure and 

predict the annoyance people feel when faced with low 

frequency noise. The research team members come from 

30 
Pennsylvania State University, Purdue University, the 

University of Central Florida, the Boeing Company, GE 

Aircraft Engines, Rannoch Corporation, the Volpe National 

Transportation Systems Center, and Wyle Laboratories. 

In the past year, the team conducted a low frequency noise 

study at Washington Dulles International Airport together 

with a NASA/Volpe assessment of “start of takeoff roll” 

source noise. They logged over 500 recordings of thrust 

reverser and sideline on-acceleration source noise, 41 

hours of impact assessments involving residences of different construction types, and concurrent profiles of combined 

meteorological, wind, and temperature data. They also 

collected source noise recordings at the houses and 

runway locations using high quality microphones, and then 

labeled acoustic signatures for each of the various types of 

participating aircraft. 

The signature recordings form a database that is being 

used in psychoacoustic testing. Juries of human subjects 

are reacting to the recordings, with specific emphasis on 

their perceptions of low frequency noise. This research 

may have implications on airport operations and future 

aircraft design and regulations. Eventually, it may identify 

acceptance metrics for low frequency noise and lead to 

action and technology development to mitigate the impacts 

of this type of noise. 

Developing Emissions Profiles

Under the National Particulate Matters (PM) Roadmap, the 

FAA has partnered with NASA and the aviation community 

to test selected commercial aircraft under field conditions and develop accurate emissions profiles for aircraft 

engines in current use. The participants agreed to an 

element of anonymity to avoid sensitive issues of security 

procedures and handling of proprietary data; hence, the 

tests have come to be called the “Una-Una” (unidentified 

airport, unidentified airline) study. This study focused on 

particulate matter emissions. The research team studied 

engines manufactured either by General Electric or Pratt & 

Whitney mounted on Boeing 757, Boeing 767, and McDonnell Douglas 88 aircraft. The test team included individuals 

from FAA, NASA, the National Oceanic and Atmospheric 

Administration, Volpe National Transportation Systems 

Center, University of Central Florida, University of MissouriRolla, and Aerodyne Research, Inc. 

During Phase 1 of the test, researchers held the aircraft 

immobile on the ground with their engines operating at various power settings. They measured emissions at engine 

exit nozzle and at downstream locations. Because the 

engines came from different manufacturers – and thus may 

have different rated thrust and depend on different emissions technologies – the study also provided an opportunity 

for a broader evaluation of particulate emissions than 

previously available. In Phase 2, researchers performed 

advected emissions measurements near the start of the 

runway, where aircraft generally begin takeoff operations. 

Although they initially collected samples from directly 

behind the engine, they subsequently tried to capture the 

exhaust plume as it moved a short distance downwind from 

a single aircraft, or under some runway conditions, from 

multiple aircraft. 

In addition to gathering extensive information on the level 

of particulate matter emitted under a range of power 

settings, the research team is working to answer critical 

questions about the physical and chemical properties of 

aircraft particulate matter, such as particle count, size 

distribution, particle composition, and black carbon mass. 

The researchers also evaluated different types of measurement equipment to determine how well these instruments 

measured various particulate matter characteristics. Initial 

indications show, for example, that NOAA’s Light Detec

31
tion and Ranging (LIDAR) technology failed to measure 

particles of less than 100 nanometers, while the Aerodyne 

and University of Missouri – Rolla systems successfully 

provided accurate measurement. These results will allow comparison with the measurements based on other 

technologies. Such information could prove relevant to 

a new standardized particulate matter test protocol being 

developed by the Society of Automotive Engineers (SAE).

The test team is drawing generalizations from the data and 

getting their findings peer reviewed for publication. They 

will conduct additional research on lessons learned and 

answer research questions about particulate matter aging 

and its subsequent transformation downstream during the 

next airport study conducted in October 2005 in Cleveland, 

Ohio. 

Creating the Particulate Roadmap

Regulatory and health agencies in the United States and 

other countries have found that exposure to particulates 

from a variety of sources, including aviation, may be hazardous to human health. These emissions may also adversely affect global climate. Although aviation is a known 

source of particulate emissions, there is little information on 

the characteristics of these emissions. To collect accurate 

and reliable scientific data on the characteristics of aviation 

emissions (rate of occurrence, particle size distribution, 

number density, composition, behavior in the environment, 

etc.), the FAA, NASA, DoD, the Environmental Protection 

Agency, engine and aircraft manufacturers, airports and 

airlines, and other stakeholders joined forces to develop a 

unified R&D and regulatory “Particulate Roadmap.” 

This roadmap will help researchers understand and quantify aircraft particulate matter emissions in relation to other 

sources. It will also help them determine how particles are 

composed, formed, grown, and transported. The resulting long-range action plan will guide aviation technology 

development.

Significant progress continues to be made in defining all 

the work elements necessary to achieve the project goals 

as defined in the mission statement. To ensure continued 

progress, the interagency Joint Planning and Development 

Office and its Environment Integrated Product Team will 

include this work in their research roadmap.

Designing Air Quality Standards

Airports are required to demonstrate compliance with the 

National Ambient Air Quality Standards (NAAQS) to ensure 

that particulate matter emitted by aircraft operated at their 

facilities does not exceed the size allowed by their applicable version of the standards. Until hard data becomes 

available, the FAA has developed a way to estimate the 

levels of particulate matter emissions attributable to a 

particular aircraft. Known as the First Order Approximation 

(FOA), this mathematical formula correlates the “smoke 

number” that is reported in the aircraft’s original certification 

process with the generalized mass emission rates of nonvolatile particulate matter emissions. The FOA methodology also draws on limited data from other sources.

Over 70 U.S. and international government, academic, 

and industry professionals have peer reviewed the initial 

development of the FOA. Feedback has been essential in 

the steps the FAA has taken to improve usefulness of the 

methodology. With each improvement, the FOA is returned 

to the peer review group for another evaluation and comment. Important contributors to these reviews include 

participants in the National PM Roadmap, researchers 

from PARTNER, and members of Working Group 3 of the 

International Civil Aviation Organization’s Committee on 

Aviation Environmental Protection.

32 
In August 2005, the FAA released version 4.3 of the 

Emissions Dispersion Modeling System, the latest version 

of the FOA methodology to estimate particulate matter 

mass emissions from aircraft engines, including emissions 

associated with downwind concentrations. For the first 

time in the evolution of modeling system, it can be used to 

demonstrate compliance with particulate matter national 

ambient air quality standards for airport emission sources.

The FOA will continually be improved as the science of 

particulate matter emissions from aircraft engines matures. 

Although it ultimately will become obsolete as verified indices of these emission emerge, the FOA fills an immediate 

need to estimate aircraft particulate matter emissions for 

compliance purposes.

Studying the Effects of Aviation on 

the Global Atmosphere

Aviation emissions contribute to climate change from 

factors such as greenhouse gas emissions, condensation 

trails (contrails), and enhanced cirrus clouds. Contrails are 

line-shaped clouds composed of ice particles, which are 

visible behind jet aircraft, typically at cruise altitudes in the 

upper atmosphere. Depending on the temperature and 

the amount of moisture in the air at the aircraft altitude, 

contrails evaporate quickly (if the humidity is low) or persist 

and grow (if the humidity is high). 

Based on analysis of current meteorological data and on 

assumptions about future air traffic growth and technological advances, persistent contrail cover is expected to increase between now and the year 2050. Though contrails 

have been produced by jet aviation since its earliest days, 

focus on contrails has increased with the growing concern 

over climate change. It is currently estimated that regions 

of the atmosphere with sufficient humidity to support the 

formation of persistent contrails cover about 16 percent of 

the Earth’s surface. If air traffic in these regions increases 

in the future, persistent line-shaped contrail cover will also 

increase.

In 1999, the Intergovernmental Panel on Climate Change 

(IPCC) published a “Special Report on Aviation and the 

Global Atmosphere.” The 1999 report comprised a complete and thorough documentation of the state of understanding at that time of how emissions at cruise altitudes 

affect the atmosphere. A much used resource, the contents of that report have guided the ensuing research and 

have begun to influence international policy making. The 

momentum brought by the development of the 1999 IPCC 

report was not maintained; yet, the active research groups 

have made a number of significant advances in the intervening years. Recently, PARTNER developed a report to 

summarize some key insights that have emerged over the 

past five years and identified further research needed. As 

a result, PARTNER also is now conducting new research 

efforts to address key uncertainties, including investigating relationships between aircraft parameters (controllable 

inputs) and the properties of the condensation trails (contrails) generated by aircraft under a variety of atmospheric 

conditions. This research will be critical to the deliberations 

of the International Civil Aviation Organization’s Committee 

on Aviation Environmental Protection.

33
Measuring Aviation’s Greenhouse 

Gases

The World Meteorological Organization (WMO) and the 

United Nations Environment Programme established the 

Intergovernmental Panel on Climate Change to assess scientific, technical, and socioeconomic information relevant 

to the understanding of human-induced climate change, 

potential impacts of climate change and options for mitigation and adaptation. 

The FAA’s Chief Scientific and Technical Advisor for Environment is working with the Panel to revise the Guidelines 

for National Greenhouse Gas Inventories. The new guidelines, which will be published in 2006, stress harmonization 

with other sectors of the economy, introduce new scientific 

and technical material, and incorporate input from the 

International Civil Aviation Organization’s Committee on 

Aviation Environmental Protection. A key feature is a new 

methodology for computing inventories bases on newly 

available models such as the FAA-developed System for 

Assessing Aviation’s Global Emissions.

The draft guidelines will be ready for government consideration in early 2006. When published, they should be 

influential for years to come as countries seek to manage 

their greenhouse emissions.

Rewarding Research

This year, the PARTNER Center of Excellence announced 

two winners of the 1st Annual Joseph A. Hartman Student 

Paper Competition. Named to honor one of the Center’s 

founders, the contest awarded cash prizes of $2,000 to 

co-winners Nicolas Antoine and Nhut Tan Ho.

PARTNER honored Dr. Antoine, formerly of Stanford 

University and now at Airbus, for his paper, “Aircraft Optimization for Minimal Environmental Impact.” This study 

looks at the feasibility of integrating noise and emissions 

objectives into the conceptual design stage of new aircraft. 

His approach allows early quantitative analyses of tradeoffs between environmental performance end operating 

costs. It also could impact the long-term design of the next 

generation of commercial aircraft.

Formerly of MIT and now at California State University, 

Northridge, Dr. Ho, was honored for his “Design of Aircraft 

Noise Abatement Approach Procedures for Near-Term 

Implementation.” This research considers the installation 

of the Continuous Decent Approach (CDA) paradigm in 

commercial airports. While CDA clearly can reduce emissions as well as the noise affecting surrounding communities, its implementation may pose new challenges for air 

traffic control. This paper looks at many of these problems 

and suggests ways to overcome them.

The judges also awarded an “Honorable Mention” and a 

cash prize of $200 each to three students from the Pennsylvania State University:

• Peter Shapiro: “Subjective Response to Low-Frequency 

Aircraft Noise;”

• Erin Horan: “Vibration and Rattle Impact Due to Low Frequency Noise Investigated at Dulles Airport;” and 

• Remy Gutierrez: “Investigation into Low-Frequency 

Airplane Source Noise Directivity Along Runway Sideline 

During Start of Take-off Roll and Thrust Reverser Engagement.”

34 
Each of these papers relates to a larger project to quantify 

and define issues associated with aircraft low-frequency 

noise. 

Nicholas A. Jaggers, a PARTNER student at Purdue University, took second prize in the FAA Centers of Excellence 

Joint Annual Meeting Student Poster Contest for his entry, 

“Research to Examine Population Encroachment on Airport 

Operating Areas.”

The FAA also named Stephen P. Lukachko, a doctoral 

student in Aeronautics and Astronautics at MIT, “Student 

of the Year” for the FAA Centers of Excellence. He has 

developed an accounting framework to assess uncertainties and trade-offs of environmental impacts of commercial 

air transport. 

35
Sharing Human Factors Knowledge

The Human Factors Workbench provides FAA employees, 

system developers, human factors researchers, and human 

factors practitioners easy access to human factors information that supports aviation-related activities. By providing 

free on-line access (http://www.hf.faa.gov/Portal/default.

aspx) to information, the toolbox promotes knowledge sharing, allowing users to access: system development and 

process descriptions; more than 100 human factors tools; 

the Human Factors Awareness training course; and more 

than 1,600 publications, studies, and other papers assembled into a searchable database. Creation of the Human 

Factors Workbench promotes the sharing of knowledge 

about human factors best practices, and helps acquisition 

professionals, the FAA workforce, and associated participants, accomplish FAA objectives for the national airspace 

system. The Human Factors Workbench promotes use 

of important information related to solving human-system 

performance challenges in the aviation community. 

The FAA recently added new reports to the library and enhanced its search capability. Researchers also expanded 

the toolbox and updated some existing tools to reflect 

changes in the FAA Acquisition Management System. 

Following user feedback, human factors specialists revised 

the Human Factors Awareness Course. In addition, 

they finalized the evaluation components of the training 

course, providing a set of quizzes (one for each module), 

a pre-test, and a post test. Users can now print a course 

certificate of completion.

Improving Tower Siting/Visibility

In an average year, the FAA starts construction on seven 

airport traffic control towers (ATCT). Towers recently 

constructed or currently being built range in height from 

65 to 300 feet tall and cost from $11 to $80 million. These 

costs depend on several factors, such as the size of the 

base facility, whether there is a colocated terminal radar 

control facility, the equipment integrated in the tower, and 

the surrounding security requirements. But a major factor 

is the tower height and location. Each new tower costs 

millions of dollars to construct – approximately $40,000 per 

foot of height. 

In the past, tower siting (height and location) decisions 

were based on the FAA’s Airport Tower Siting Criteria (FAA 

Order 6480.4), issued in 1972. As part of efforts to update 

and revise that order, researchers collaborated with engineers and air traffic control specialists to develop, test, and 

validate a set of human performance metrics for assessing 

the impact of tower height on air traffic control tower specialist performance. After analyzing a number of methods 

to address object obscuration, object discrimination, lineof-sight angle of incidence (look-down angle), two-point 

lateral discrimination, and tower cab design human factors 

considerations, researchers developed a web-based tool to 

assist tower planners and construction engineers. 

Human Factors &

 Aeromedical

36 
The ATC Visibility Tool allows the user to manipulate basic 

or advanced visibility parameters to measure the effects 

on an observer’s ability to acquire an object visually. It 

also defines the minimum line-of-sight angle of incidence 

required for airport traffic control tower specialists to perform their necessary separation task. Users simply input 

an object, designate tower height and key point distance, 

select the outside illumination level, and the tool calculates 

minimum discrimination and slant angle (height) requirements. The tool is publicly available at http://www.hf.faa.

gov/visibility. 

As a result of this research, in June 2005, the FAA released 

for comment and interim use a revised ATCT siting policy 

that mandates the use of visibility performance measures. 

This research is having an immediate impact. It is not only 

enhancing safety by allowing researchers and engineers to 

find and resolve potential problems before tower construction begins, but it is also contributing to significant cost 

savings. 

Designing the Future En Route 

Workstation

The expected 50 percent increase in air traffic by 2020 

will require a dramatic change in how air traffic controllers 

work. To determine the feasibility of integrating automation functions in the tower that would allow controllers to 

handle additional traffic, researchers are examining ways 

to present and integrate information, measure controller operations, and ensure human factors considerations are reflected in the controller workstation of the future. The goal 

of this research project is to minimize the number of steps 

and amount of time an air traffic control specialist needs to 

either retrieve or input data into an automation system. 

In one of the most complex person-in-the-loop simulation studies ever conducted at the FAA William J. Hughes 

Technical Center, researchers exposed controllers to 

three workstation concepts and three levels of traffic. The 

workstation concepts included a baseline condition (Display 

System Replacement, Traffic Management Advisor, User 

Request Evaluation Tool, and data link-digital communications), a generic future concept (identical Radar Controller and Radar Controller Associate workstations), and a 

specialized future concept (where the Radar and Radar 

Associate workstations reflected some specialization based 

on the function). The three traffic levels consisted of 21 

(today’s traffic), 28 (33 percent traffic increase), and 35 

(66 percent traffic increase) aircraft under control. The 

experiment also included scenarios to address the effect of 

providing a conflict probe on the radar controller workstation and of upgrading the data-side display from a conventional configuration to one that includes a radar display 

with integrated automation functions. In addition, the study 

included scenarios to address the effect of providing data 

link-digital communications functionality by removing it from 

the available tools. 

Data analysis continues on the project. The results of this 

research project may help increase controller productivity and enable the air traffic system to increase capacity 

through user-centered automation. 

Determining the Benefits of the En 

Route Information Display System

The FAA plans to deploy a new system that will provide 

controllers real-time electronic access to weather data, 

aeronautical data, air traffic control procedures documents, 

Notices to Airmen, pilot reports, and other information. Prototype systems are currently being assessed at the Boston, 

Jacksonville, and Salt Lake Air Route Traffic Control 

Centers. 

As part of efforts to develop the En Route Information 

Display System (ERIDS), a team of researchers is studying controller information needs. In particular, they are 

assessing the benefits of the new system from a controller 

perspective, focusing on potential workload reduction and 

convenience. To date, researchers have identified current 

paper sources of air traffic system information, determined 

how often controllers access this information, examined 

the time and motion required for a controller to access 

information, and studied the importance and currency of 

the information. 

To determine the impact, workload cost, and benefits 

of ERIDS on the total system, baseline information was 

compared to performance data when using ERIDS. Radar 

controllers, radar associates, supervisors, and others took 

part in the study. The team also developed a test plan and 

began data collection efforts on the prototype systems in 

late 2005. In addition to this study, researchers are review

37
ing system hardware, evaluating integration into controller 

workstations and location of system hardware.

The FAA will use the results of this research to determine 

the human performance impact of the new system. This 

information will be an important input to the cost-benefit 

analysis prior to making a final decision on system acquisition and national deployment. 

Developing a Modular Display Concept for Air Traffic Control Towers

 Currently, each air traffic control facility is responsible 

for its own tower cab design. Lacking any central human 

factors design for tower displays and the arrangement of 

equipment within the tower cab, each tower is a unique 

facility that has evolved over time as a result of funding, 

traffic demand, and individual facility decisions. As a result, 

most tower cabs have a piecemeal design that places 

equipment where room is available without a clear understanding of controller information requirements. 

To create a more efficient cab design, human factors 

researchers are developing a modular concept of air traffic 

control tower design. In support of this effort, they collected 

data that will help them understand tower controller work 

patterns and the information required to perform controller 

tasks, with emphasis on the interaction with tower cab systems. They also produced sketches of tower cab layouts, 

recording the type and placement of equipment relative to 

controller positions. They developed flow diagrams to identify controller tasks, task elements, communications and 

coordination, and the information required to support task 

goals for each position in the tower cab (e.g., local, ground, 

flight data, clearance delivery). The diagrams identify 

which information elements or sources can serve controller 

requirements across multiple tasks and between positions. 

Once research is complete, the FAA will have a master 

concept for tower cab design that uses a modular approach 

to meet the tailored display needs for each tower.

Transforming a Safety Culture

To understand better and improve the organizational safety 

culture, human factors researchers began assessing the 

culture attributes of FAA Air Traffic Organization Technical 

Operations facilities. 

The research team conducted a series of focus group 

sessions at the Seattle, St. Louis, and Potomac Terminal 

Radar Approach Control facilities. They selected these facilities because of their potential to provide a realistic sampling of work environments and job types without having to 

conduct a large-scale nationwide study. After interviewing 

participants, the team developed a safety culture survey 

instrument that is now ready to be tested. 

To determine overall trends in the safety culture, researchers hope to conduct a longitudinal study—repeated 

measurements over a long period of time. A single survey 

would simply provide one data point, a snap-shot, which is 

an important starting point, but not nearly as useful as the 

long-term trend report. 

Data from the study will provide an in-depth understanding 

of the baseline status of the organization’s safety culture. 

Once the baseline is established, subsequent measurements will allow the organization to assess the effectiveness of various interventions that may be implemented in 

the course of the culture change efforts.

38 
Enhancing the Aircraft Certification 

Job Aid

Aircraft certification requires judgments about whether new 

aircraft designs will be safe for current and future pilots. 

Although studies have shown that design-induced human 

performance errors have contributed to many aviation incidents and accidents, there is a lack of guidance describing 

what human performance areas should be evaluated. Until 

recently, only a few methods have been available to help 

certification personnel predict the future occurrence of such 

errors based on analysis of the flight deck design. The 

Aircraft Certification Job Aid is a computerized decisionsupport tool designed to help aircraft certification personnel 

ensure aircraft flight deck technologies are user friendly 

and safe.

FAA-funded researchers at Research Integrations, Inc., 

previously developed a PC-based software tool with three 

major databases addressing regulatory information, flight 

deck components, and human factors considerations. 

Early versions of the Job Aid addressed Part 25 Transport 

Category Aircraft displays, controls, and integrated flight 

deck systems such as the flight management system. Human factors researchers have added information on Part 

25 integrated flight deck systems and summaries of Part 

25 regulations for human factors considerations related 

to equipment, tasks and procedures, and testing assumptions. Additionally, human factors summaries of Part 23 

Commuter Category Aircraft regulations and Advisory Circulars for human factors considerations related to displays, 

controls, and integrated flight deck systems are complete. 

A limited number of certification personnel continue to use 

the fielded version of the job aid in their jobs. They provide 

important feedback for future version enhancements. 

Evaluating Electronic Flight Bags

Airlines are now introducing electronic flight bags into 

the flight deck, bringing with them many human factors 

challenges. The FAA defines an electronic flight bag as an 

electronic information management device used by crew 

members to obtain information currently provided in paper 

form. Although these devices may look like familiar equipment, the flight deck perspective of their flexible configurations and functionality sets them apart from traditional 

equipment.

Human factors research is needed to provide input for 

certification, operational approval, and training guidance, 

including input to Advisory Circulars, as well as to mitigate 

risks associated with implementation and integration on 

the flight deck. The focus of the current effort is to develop 

more practical aids for field evaluations of electronic flight 

bags by FAA field inspectors. Such tools will benefit the 

FAA, system designers, and operators by providing structure for human-factors evaluations. They will be customized for both aircraft certification specialists and Flight 

Standards inspectors. 

Researchers continue to refine the Electronic Flight Bag 

Usability Assessment Tools, developed with FAA funds 

by the Volpe National Transportation Systems Center. In 

2005, researchers refined the assessment tool for FAA 

Aircraft Certification specialists. They participated in 

workshops with the intended users, received feedback, 

and incorporated the results into the assessment tools. 

Additionally, working closely with FAA pilots and capitalizing 

on the products previously developed for aircraft certification, researchers developed an initial usability assessment 

checklist for inspectors. 

39
Determining Effective Flight 

Symbology

New technology and electronic displays are becoming 

more common in the cockpit. Because display technology 

varies widely from manufacturer to manufacturer and device to device, researchers are working to determine what 

aeronautical chart symbology (airports, roads, railroads, 

terrain features, obstructions, etc.) most effectively presents moving maps and electronic chart displays. The goal 

of this work is to identify features of navigation symbology 

that are problematic when presented on electronic displays, 

and develop a method to design and evaluate symbology 

that takes into account the different media (e.g., paper vs. 

electronic) and platforms on which they will be displayed. 

FAA-funded researchers at the Volpe National Transportation Systems Center, have conducted two experiments. 

They first tested the intuitiveness of navigation symbols 

that are constructed from feature rules (e.g., an outer circle 

implies that it is a “fly over” point). The second experiment 

identified stereotypes for the navigation symbols. Results 

from this research will help the FAA and industry establish 

standards for symbology. The researchers are currently 

working with the Society of Automotive Engineers (SAE) 

G-10 Aeronautical Charting Subcommittee in its efforts to 

update the recommended symbol set in SAE Aerospace 

Recommended Practice 5289. The subcommittee plans to 

use the results of these experiments for input to the recommended symbol set. 

Understanding Human Error 

For the past six years, the FAA has used the Human Factors Analysis and Classification System (HFACS) to examine human error associated with commercial and general 

aviation accidents. Designed by the military and modified 

for FAA use by FAA and University of Illinois researchers, 

HFACS is a theoretically based tool for investigating and 

analyzing human error associated with high-risk environments such as aviation. Researchers have proven that 

HFACS is a reliable tool to conduct human factors analysis 

of commercial and general aviation accidents.

The research team continues to conduct focused investigations of human error associated with a variety of aviation 

communities, including: commercial aviation; general 

aviation in Alaska versus the rest of the U.S.; helicopter 

emergency medical services; and aviation maintenance. 

To date, they have examined and classified over 25,000 

accidents using the HFACS framework. This encompasses 

all civilian aviation accidents since 1990. 

Researchers also have integrated HFACS and other traditional National Transportation Safety Board (NTSB) situational and demographic variables into a single, web-based 

database, which allows for human error examinations of 

the accident data. The data provide critical information in 

the development of “data-driven” interventions to prevent 

accidents. These interventions are catalogued into the 

human factors intervention matrix, which maps the causal 

categories outlined by HFACS to five human factors 

approaches to intervention – organizational/administrative, human/crew, technology/engineering, task/mission, 

and operational/physical intervention. The team also has 

completed a preliminary investigation of current FAA and 

proposed NTSB safety interventions using HFACS. Results 

from this effort will provide the baseline information necessary for assessment, modification, and/or development of 

future safety interventions.

40 
Improving Human Factors in 

Aviation Maintenance

Attention to human factors issues in maintenance and engineering has become a cornerstone for ensuring continuing 

safety. To help achieve our safety goal, the FAA released 

The Operator’s Manual for Human Factors in Aviation 

Maintenance. Written in response to industry requests 

for simplified instructions, the manual provides a short 

and concise listing of six key factors that will help ensure 

appropriate human factors input into any maintenance 

organization. 

Available to the public, at no cost on the Internet (http://

www.hf.faa.gov/opsmanual), the manual provides easily 

understood information on event investigation, documentation, training, shift turnover, and fatigue/alertness. The final 

chapter addresses the issue of program sustainment and 

cost justification. For each of the subjects covered, the 

manual provides information on why the topic is important, 

how the human factors practice can be implemented into 

an organization, how to measure success, and where to 

find additional information.

The manual is a result of joint government/industry effort to 

improve aviation maintenance human factors. In addition 

to the FAA, participating organizations included: NASA; 

jetBlue Airways; Northwest Airlines; US Airways; American Airlines; FedEx; Saint Louis University; the Boeing 

Company; and major airline labor organizations. Users 

of the manual include aviation maintenance managers, 

quality managers, and training personnel. It provides 

supplemental information for FAA aviation safety inspectors 

and personnel overseeing airline maintenance, repair, and 

overhaul.

Establishing Proficiency Standards 

for Advanced Aircraft

The advent of technically advanced general aviation aircraft, such as the Eclipse 500, requires that pilots, instructors, and evaluators master a wide variety of new concepts 

and skills. To help the aviation community, researchers 

produced a comprehensive list of knowledge and skills that 

are important for pilots, instructors, and evaluators who 

operate, teach, and test in technically advanced aircraft. 

This research will be used to develop a new technical publication to serve as an official information source for these 

new areas of proficiency. It will be similar to the Airplane 

Flying Handbook (FAA-H-8083-3), Instrument Flying 

Handbook (FAA-H-8083-15), and the Pilot’s Handbook of 

Aeronautical Knowledge (FAA-H-8083-25).

Using Advanced Technology for 

General Aviation Inspection 

Training

The majority of all general aviation aircraft inspections are 

visual. As aircraft become more technologically advanced, 

the inspector’s job becomes more difficult. To prepare 

inspectors for new aircraft, new tasks, and new inspection 

techniques, FAA human factors specialists are demonstrating how advanced technology can improve training. This 

effort will reduce inspector errors in the general aviation 

maintenance environment. 

FAA-funded researchers at Clemson University have 

developed a prototype computer-based training tool called 

the General Aviation Inspection Training System (GAITS), 

which will improve defect detection. This training program 

is organized into separate modules: introduction; training; 

simulation; design and analysis; and, simulator. Specific 

activities conducted in support of the development of 

41
GAITS included: development and evaluation of alternate 

interfaces, and development of scripts and story boards. 

GAITS allows for individualized training, as well as evaluation of a maintenance inspector’s performance. The Design and Analysis module, for example, helps the instructor 

customize the training program to suit individual needs. If 

an inspector needs help in locating corrosion defects, he or 

she can access information about different types, severity, 

and locations of corrosion. Similarly, the simulator can be 

tailored to provide specific feedback to enhance the learning experience.

Developing a Web-Based Surveillance and Auditing Tool

The FAA is developing a web-based surveillance and auditing tool (WebSAT) that will provide a standardized format 

for maintenance data collection, reduction, and analysis to 

identify factors contributing to maintenance errors. The goal 

of this research is to reduce errors and improve the reliability of aircraft inspection operations. WebSAT will aid in 

standardizing the data collection process supporting analysis of maintenance errors prior to aircraft dispatch. This will 

facilitate analysis across airlines. In addition, WebSAT can 

be combined with existing training programs to facilitate 

consistency in inspection training, provide adaptive training, 

and support record-keeping and performance monitoring.

A FAA-funded research team at Clemson University is 

conducting research in the areas of user-interface, data 

reduction techniques, and data analysis strategies. The 

research team is also developing a reliable risk model to 

analyze data collected from various surveillance, technical 

auditing, and airworthiness directive work functions. They 

have completed the technical auditing module.

Establishing Requirements for 

Simulator Training

FAA-funded research is underway at the Volpe National 

Transportation Systems Center to establish flight simulator 

qualification standards for pilot training. Because air carrier 

certification, qualification, and continuing qualification is 

accomplished in simulators by most air carriers, simulation 

must accurately replicate the airplane and aviation environment. 

Previous studies investigated the effects of motion in 

recurrent pilot training. Researchers recently completed 

work with a major air carrier and its Boeing 717-200 fleet 

to determine the effects of simulator motion on initial pilot 

training. They trained and tested over 40 pilots on a full 

flight simulator airplane after completion of ground school. 

They trained half of the pilots with motion and the other half 

without motion. To assess the effect of motion on transfer 

of training, the research team then tested all of the pilots 

in the simulator with motion as a stand-in for the airplane. 

They collected data from the simulator and with questionnaires. Analysis is underway, and additional research 

must be performed before the researchers issue their final 

conclusions. Early results, however, support previous findings and suggest that flight-simulator motion will not benefit 

recurrent training.

42 
Training Pilots and Crew

In most air carrier pilot training programs, instructional 

strategies that seek to improve teamwork in the cockpit 

(crew resource management skills) are treated as standalone entities. However, research indicates that crew 

resource management should be integrated into all aspects 

of training. Situational training will improve pilot performance and enable air carriers to prepare pilots to manage 

more effectively the range of flight situations they may 

experience. 

Current FAA-funded research at Battelle Memorial Institute 

is investigating the advantages and implications of using 

a situational training framework. Based on this work, 

researchers expect to develop a catalog of situational 

events that the FAA and air carriers can employ in training 

development. They plan to develop a training framework 

that integrates crew resource management training with 

the more technical training. Such a training program would 

make pilots aware of the consequences of situational factors and tap crew resource management skills to manage 

and resolve potentially dangerous flight situations.

Standardizing Event Reporting

Over the last decade, the FAA has introduced a broad 

range of industry safety programs designed to enhance 

safety by collecting data on human and aircraft performance. One of these programs is the Aviation Safety 

Action Program (ASAP) developed to encourage airline 

employees to voluntarily submit safety-related reports. 

In a typical report, the pilot voluntarily writes a short narrative describing the event and the causal factors, and provides recommendations to prevent recurrence. From this, 

air carriers prepare training objectives. Because ASAP 

programs are carrier specific, the FAA is working to develop 

a means to share data and accident/incident mitigation 

strategies among the various air carriers collecting ASAP 

data. To accomplish this, the Agency must develop uniform 

incident classification tools that various air carriers can use 

to collect and analyze their data. 

In 2005, FAA-funded researchers at the American Institutes for Research developed, tested, and validated the 

Aviation Causal Classifications for Event Report System 

in coordination with a regional air carrier. Completion of 

this taxonomy yielded a document that illustrates seven 

high-level causal contributors to human error in aviation, 

and shows the hierarchical assignment of an additional 

70 detailed factors to these seven categories. Definitions 

are provided both at the category and factor level. This 

taxonomy provides a uniform set of descriptors and is now 

available to industry.

43
Training Pilots for Unexpected 

Events

The goal of this research at the University of Central 

Florida is to provide the FAA and air carriers methods to 

develop training curricula that will prepare pilots to respond 

to abnormal or emergency operational conditions. Training pilots to cope with and react to unexpected events 

continues to be a challenge for the air carrier industry. 

Each year, the air carriers conduct special training sessions to train their pilots for newly identified, safety-critical 

maneuvers and operations. Yet, at the same time, this 

type of event-specific training will not, and cannot ,prepare 

pilots for all possible eventualities. Instead, pilots need to 

be prepared to react flexibly and creatively to previously 

unexperienced events. 

This research project addresses the psychological, cognitive, and behavioral processes contributing to surprise, and 

identifies factors underlying events perceived as abnormal 

or emergency. In 2005, researchers completed a field 

study investigating factors underlying a pilot’s ability to recognize and react to various flight abnormalities, including 

upset recovery. The research team has analyzed the data 

and issued a final report outlining preliminary suggestions 

for training development and recommendations for further 

research. Suggested actions include development of 

training interventions to manage unexpected events, such 

as scenario-based training, metacognitive training, and 

adaptive expertise training. These interventions will be 

prototyped and tested in upcoming years.

Understanding the Effects of Mixed 

Fleet Flying

FAA-funded scientists at Research Integrations, Inc., 

conducted a longitudinal study to identify whether skill 

degradation occurs when pilots have not recently flown the 

aircraft upon which they have been trained. The primary 

topics of investigation included examining the possibility of 

pilots making errors in one airplane because of their experience with another airplane, and the likely degradation of 

pilot skills if they have not flown one of the planes for up to 

six months. Prior to this study, researchers had identified 

the potential for human error if pilots trained in one aircraft 

flew another type of aircraft without training. 

Researchers have analyzed data from this study to 

determine the magnitude of potential safety vulnerabilities. 

They identified one safety concern related to the design of 

the Takeoff/Go-Around (TOGA) switches. Other findings 

showed that several procedural and training items must 

be addressed for pilots to fly successfully two types of 

airplanes. They also determined that for most of the operations and maneuvers tested, a six-month currency cycle 

is acceptable. Research results will help the FAA and the 

airlines to identify constraints and establish requirements 

for air carriers where pilots fly two different types of aircraft. 

44 
Analyzing Opiates in Postmortem 

Fluids and Tissues

Researchers in the Aerospace Medical Research Division 

of the FAA Civil Aerospace Medical Institute (CAMI) are 

making significant advances in the analysis of postmortem 

fluids and tissues following fatal aircraft accidents. Forensic toxicology researchers routinely detect and measure 

drugs, alcohol, toxic gases, and toxic industrial chemicals 

in the remains of accident victims to rank these factors 

among the causes of accidents. They also analyze clinical 

chemical parameters in search of significant health trends 

affecting aviation personnel. 

Opiates are some of the most widely prescribed drugs in 

the U.S., but they are often abused. Derived from a seedpod of the poppy plant, their general effects include sedation, slowed reflexes, sluggish movements, and slowed 

breathing. The research team has developed a simple 

method to determine the presence and qualities of as many 

as eight opiate compounds from a single sample. 

One of the primary goals of this research is to make sure 

drug positives have not resulted from the incidental use 

of common food products or postmortem artifacts. Eating 

foods such as poppy seed bagels and muffins, for example, 

can make a person test positive for morphine and codeine. 

This person also is likely to test positive for thebaine, a 

unique marker for poppy seeds. In contrast, a person 

taking prescription codeine tests positive for codeine and 

morphine but not for thebaine. Until recently, toxicologists 

could not easily and quickly tell the difference between codeine use and poppy seed consumption in laboratory tests. 

Studying Gene Expression Changes 

in Response to Mild Alcohol 

Ingestion 

Aerospace medical researchers are conducting focused 

studies on the expression, function, and interactions 

of genes to identify ways of preventing accidents. For 

example, researchers are working to identify genes associated with impairment. This research will ultimately result in 

new methods to identify pilots whose potential impairment 

might lead to an accident. 

Among other investigative techniques, researchers use 

microarrays (also known as “DNA chips”) in a method that 

screens a biological sample for the relative expression 

pattern of all its contained genes. They have demonstrated 

the effectiveness of microarray analysis for detecting 

mild (< 0.08 percent) alcohol consumption and identifying 

genes associated with alcohol consumption. This genetic 

knowledge can now be used to evaluate aviation accidents 

in terms of alcohol consumption and impairment. 

Functional genomics research pushes the FAA’s aerospace 

medicine community towards the forefront of scientific 

discovery and therefore the realization of state-of-theart safety processes. Continued investigation will allow 

researchers to tell the difference between alcohol that developed in a victim’s body after death as a result of normal 

microbial activity and the remains of alcohol that the victim 

had actually ingested. This research directly supports the 

Office of Science and Technology Policy Interagency R&D 

Fiscal Year 2005 priorities by enabling a molecular level understanding of normal life processes and those associated 

with disease. This understanding will lead to improved 

aeromedical safety operations.

45
Using the Scientific Information 

System for Research Studies

Researchers apply computational and analytical methods 

to understand very complex biology. They have developed 

a scientific information system that permits the comprehensive, systematic study of pilot-related mishaps (accidents 

and incidents) due to medical and human factor causes. 

The process involves examination of millions of records 

from FAA medical certification efforts in combination with 

accident investigation findings from the National Transportation Safety Board. 

Researchers recently completed the evaluation of atrial 

fibrillation (AFIB), a medical condition of importance to 

aeromedical examiners when evaluating aircrews. AFIB 

is the most common form of arrhythmia, a heart condition 

affecting more than two million people annually. Its prevalence increases with age and complications include stroke 

and congestive heart failure. Bioinformatics research has 

found that the overall safety record of pilots with AFIB is no 

different from that of pilots in general. Also, the mishaps 

studied were not related to the medical condition of the pilots. This review provides a fact-based foundation for decision-making and supports the safety of current certification 

procedures. Accident precursors are becoming much more 

visible as a result of this type of research, thereby enabling 

more effective and timely introduction of countermeasures. 

46 
Testing the LASER Transmissivity 

of Aircraft Windows 

Between January 2004 and January 2005, 53 out of 90 reported LASER (Light Amplification by Stimulated Emission 

of Radiation) sightings were associated with commercial 

aircraft. Thirteen of the 90 reports resulted in some degree 

of pilot visual impairment or distraction. Brief exposure to 

a LASER beam can cause discomfort and temporary visual 

impairments such as glare, flash-blinding, and afterimages. 

To a pilot, these visual distractions can produce spatial 

disorientation or loss of situational awareness.

Reports of intentional and unintentional illuminating of 

aircraft by LASERS triggered new Department of Transportation rules on the reporting of LASER sightings and 

subsequent investigation of the events. As part of an 

ongoing research program, the vision research team collaborated with the U.S Army in LASER testing involving 

eight aircraft windscreens. These tests addressed related 

safety concerns of both the Department of Homeland Security (DHS) and the FAA. Partial analysis indicated that, 

as expected, LASERS in the visible light spectrum easily 

transmit through cockpit glass. 

Simulating Aircraft Cabin 

Evacuation

Airliners certified by the FAA to operate in the national 

aerospace system generally must pass a test to evacuate 

a full load of passengers and the flight crew in 90 seconds 

with one half of the exits blocked. Because real-life certification tests for passenger cabin evacuations are expensive 

and dangerous, the test is usually limited to a single event 

under fixed conditions. Actual accidents may result in a 

variety of damage conditions affecting cabin evacuation. 

Damaged doors, broken seats, blocked aisles, fire, or 

airframe damage may impede evacuation and cannot be 

included in most testing. 

To provide information on aircraft designs and potentially 

supplement certification procedures, FAA researchers 

collaborated with Rutgers University to develop a computational aircraft evacuation model that uses features such 

as the shortest distance to exits, speed of an evacuation 

cue line, gaps in the evacuation cue line, and flow rate at 

exits. It has evacuees cut in front of one another in a cue, 

move to a different exit if the line is moving too slowly, and 

engage in other behaviors characteristic of aircraft evacuations. 

Researchers applied the model to several aircraft, including 

the Airbus 320 and 380 and the Boeing 767 and 777. With 

further development and validation, the model may be 

used to improve training strategies to enhance passenger 

survival rates in the event of an accident. It will also help 

to enhance escape simulation efforts studying the role of 

cabin fire and smoke, optimize aircraft cabin design and 

escape routes, and develop assisting devices.

47
Securing Information Systems

Visitors to sensitive information sites may not find what 

they are looking for in a single document, but when they 

combine information from various documents – within and 

across sites – they may learn more than the keepers of the 

sites intended to reveal. Information managers need automated tools that will generate plausible “concept chains” 

to expose such links. These tools would sift through 

extensive collections of documents to detect risks and 

identify seemingly innocuous information that, when pulled 

together from various sources, can yield useful intelligence 

to an adversary.

A project is underway to develop a new search engine that 

seeks hidden vulnerabilities and will be used to protect the 

FAA’s sensitive information assets. The next phase to be 

completed in FY 2006 will demonstrate a prototype on actual data sets and automatically generate detailed graphs 

revealing potentially hidden associations among semantic 

concepts. Eventually, the search tool may also be used for 

other applications, such as helping biomedical researchers 

conduct more effective investigations into the connections 

between genes, proteins, and disease. 

The FAA must also be prepared to prevent cyber attacks 

against its safety-critical mission support networks and 

systems. Adaptive intrusion quarantine research combines 

the proactive capabilities of behavior-based tools with the 

reactive effects of rules-based tools. Although this is the 

only research project in the Federal Government currently 

using this strategy to protect against security threats, its 

commercial-off-the-shelf architecture would make it readily 

transferable. 

Costing Secure Software Systems

The FAA is currently studying the feasibility of adding a 

security module to the University of Southern California-developed Constructive Cost Estimation Model (COCOMO II), 

and using the model to estimate the cost of adding security 

to systems. The results will identify security cost drivers 

and provide a tool for program managers to evaluate the 

cost benefits for security elements. With the current COCOMO II, users can estimate the cost, effort, and schedule 

involved in planning a new software development activity. 

There is a need for this tool as there is a wide variation 

in the additional estimated costs involved in developing 

software–intensive systems that require security. Other 

government agencies have expressed an interest in the 

progress of this project.

48 

Information 

Technology
Currently, researchers are developing simple “rule-ofthumb” costs, based on security cost drivers, cost estimation relationships, and applying the COCOMO II security 

extensions to a small number of pilot security projects.

Collaborating to Improve Information System Security

Federal Agency Administration of Science and Technology 

Education and Research (FASTER): The National Science 

and Technology Council Subcommittee on Networking and 

Information Technology R&D recently created FASTER as 

a Community of Practice for the highest level of federal 

information specialists who administer science and technology education and research programs. FASTER representatives, including FAA researchers, seek to accelerate 

deployment of promising research technology, share 

information on protocols, standards, best practices, and 

coordinate technology assessments and test bed development through agency collaboration. The group is pursuing 

the exchange of information in a number of areas including the Federal Enterprise Architecture, Internet Protocol 

version 6 (IPv6), the semantic web, and the Federal Data 

Reference Model that combines elements of the Semantic 

Web and the Federal Information System.

Center for Identification Technology Research (CITeR) :

The CITeR is a National Science Foundation Industry/University Cooperative Research Center focusing on biometric 

identification technology. Its research portfolio addresses 

identification technologies that encompass vulnerabilities, 

multimodal systems, biometric modalities, biometric image 

coding and quality, performance framework, system modeling, and socio-legal and business studies. Twice yearly 

participation in the organization allows the FAA to leverage 

R&D in the area of identification technologies funded by the 

National Science Foundation, industry and other federal 

government sponsors. As a member, the FAA gains:

• Access to students involved in center research as future 

employees;

• Cost-effect, highly leveraged research; 

• Access to interdisciplinary faculty teams spanning health 

sciences, the sciences, and engineering to address 

cross-cutting biometric system challenges; 

• Access to a broad spectrum of research labs; 

• Advance copies of research results and publications; and

• Proprietary position on technology transfer licensing. 

The FAA recently joined the Air Force Research Laboratory and George Mason University to identify and mitigate 

potential attack paths to mission critical resources. Through 

this work, called Combinatorial Analysis Utilizing Logical 

Dependencies Residing on Networks, researchers are 

promoting earlier detection and faster resolution of security 

events and increasing productivity levels. Specifically, they 

are: 

• Providing context for total network security;

• Analyzing network modifications;

• Prioritizing potential security incidents;

• Addressing insider and outsider threat; and 

• Reporting only those vulnerabilities associated with possible attack paths.

In addition, through this project, the FAA is developing critical enhancements to support information system security 

architecture optimization.

MIT Center for Information Systems Research (CISR): The 

Center for Information Systems Research (CISR) conducts 

field-based research on issues related to the management 

and use of information technology (IT) in complex organizations. Established at the MIT Sloan School of Management 

in 1974, the mission is to develop concepts and frameworks to help executives address the IT-related challenges 

of leading increasingly dynamic, global, and informationintensive CISR research. The associated identification of 

best practices could benefit to the national airspace system 

and the business systems that enable the operation of the 

Agency. Expectations are that FAA operational procedures, acquisition policies, and orders will be updated to 

incorporate the results as a current best practice. 

49
Deploying Automatic Dependent 

Surveillance–Broadcast (ADS-B)

Automatic Dependent Surveillance–Broadcast (ADS-B) 

has emerged as the FAA’s leading “technology opportunity” 

for transforming the national airspace system into the Next 

Generation Air Transportation System. ADS-B is a two-way 

data link system that supports both “core surveillance” and 

“cockpit based-capabilities” within a single multifunction 

display. 

ADS-B onboard avionics send a radio message about 

once per second giving the aircraft’s position, velocity, 

identification, and other information. The position information is derived from the highly accurate Global Positioning 

System. Aircraft equipped with ADS-B cockpit displays can 

receive reports from similarly equipped aircraft near them 

as well as from ground-based systems. Broadcasts also 

can be received by air traffic surveillance services and the 

airlines. The sharing of situational awareness among aircraft, air traffic control, and airlines could reduce operation 

and maintenance costs, increase efficiency and capacity, 

and improve safety.

Work continues on development of the ground infrastructure to integrate ADS-B into the national airspace system. 

Researchers completed a data collection effort to help 

develop ADS-B validation techniques. They also tested a 

prototype ADS-B ground receiver developed by Raytheon 

Systems, Ltd. In addition, they undertook data collection, 

test, and analysis of ADS-B data links and continued support of international ADS-B standards development. 

The FAA’s Safe Flight 21 Program is currently delivering 

ADS-B services along the East Coast from southern New 

Jersey to Florida, as well as parts of Ohio, North Dakota, 

and Arizona. It is also planning service expansion to 

Pennsylvania and Tennessee in the near future. The FAA 

recently evaluated the business case for ADS-B technology, and is in the final stages of making a decision for a 

national ADS-B strategy.

Advancing the Capstone Program

The FAA has demonstrated that Capstone technologies 

can improve aviation safety and efficiency in Southwest 

and Southeast Alaska. Aircraft in both areas are now 

equipped with avionics that display the positions of other 

aircraft along with weather and terrain data. Additionally, Capstone-equipped aircraft in Southeast Alaska can 

now fly routes based on the use of the Global Positioning 

System with Wide Area Augmentation System augmentation. These capabilities support safe operations at lower 

altitudes than those supported by land-based navigational 

aids.

The Capstone effort has contributed to a steady decline in 

accident rates in Southwest Alaska. A MITRE Center for 

Advanced Aviation System Development and the University 

Safe Flight 21/Alaska 

Capstone

50 
of Alaska study reports that, during the last three years, 

the accident rate for Capstone-equipped aircraft was 47 

percent lower than for an equipped aircraft. 

Capstone’s Wide-Area Multilateration Project has demonstrated a way to augment ADS-B capabilities. Transponders aboard ADS-B-equipped aircraft in the Juneau 

terminal area now transmit identity and location data to a 

network of ground sensors. The complementary wide-area 

multilateration technology enables situational awareness in 

areas that lack radar coverage. 

Capstone is preparing an investment business case for 

using the wide area augmentation system statewide to 

replace existing navigational aids. By 2007, the FAA envisions that this four-year effort will reduce operational costs 

in addition to improving safety.

Demonstrating the System Wide 

Information Management (SWIM) 

System

System-centric, or point-to-point, operations characterize 

today’s national airspace system. Networks can enable 

multiple parties to share information by linking individual 

systems together. For example, shared networks would 

enable the FAA to share information with the international 

aviation community, other government agencies, and the 

aviation industry. Systemwide information management 

will help transition the national airspace system to networkcentric operations by providing the infrastructure and 

associated policies and standards to enable system-wide 

information sharing. Underlying this transition is a scalable, 

standards-based network architecture—to be developed 

through this project—that seamlessly and securely connects users with the information or data they need.

Researchers and engineers at the Boeing Phantom 

Works, in Herndon, Virginia, successfully demonstrated 

the System Wide Information Management test bed and 

system prototype’s capabilities to support information and 

data sharing among various national airspace systems. 

The test highlighted a number of system attributes, including timely information exchange, efficient use of network 

assets, common core services for processing and distribution, and the accessing and integrating of new information 

sources through simpler, lower cost and reduced-risk 

interfaces. 

Automating Airborne Flight Alerts 

On board data can indicate critical flight conditions such 

as when an aircraft deviates from its course when it enters 

restricted airspace, or when its cabin suddenly loses compression. Providing air traffic controllers timely access to 

this type of information could help them prevent accidents; 

however, the data are generally available only from the 

flight crew through voice communication or through post 

incident retrieval of the aircraft’s flight data recorder. The 

automated airborne flight alert system, currently under 

development, will automatically and independently detect 

problems in flight and generate an alert to ground agencies. 

When the Automated Airborne Flight Alert System detects 

anomalous flight conditions, it quickly separates safety from 

security issues. It then automatically transmits information 

to the proper organizations, including those linked to the 

national airspace system, to aid in collaborative decisionmaking. Since the system’s in-flight data recorder provides 

near real-time data, implementation will not require new 

technology, hardware, or aircraft recertification. The 

research team has successfully demonstrated the proofof-concept, and a flight demonstration is scheduled for FY 

2006.

51
critical research

for aviation’s future

Federal Aviation Administration

Operations Planning Research & Development Office 

800 Independence Avenue, SW

Washington, DC 20591

http://research.faa.gov

TC06-0019