by Lune E. Wulhce 

Two Decades With 

NASA Langlev’s 

737 Flying LaKoiatory 

The NASA History Series 

NASA SP-42 16 

National Aeronautics and 

Space Administration 

NASA History Office 

Washington, D.C. 1994 
Library of Congress Cataloging-in-Publication Data 

Wallace, Lane E., 1961- 

Airborne Trailblazerlby Lane E. Wallace. 

“Two decades with NASA Langley’s 737 flying laboratory.” 

Includes bibliographical refercnccs and index. 

I. Langley Research Center. 

p. cm.-(The NASA history series) (NASA SP: 4216) 

2. Aeronautics, Commercial-Research-United States-History. 

3. Boeing 737 (Jet transport) 4. Research aircraft-United States. 

I. Title. 11. Series. 111. Series: NASA SI’: 4216. 

TL521.312.W35 1994 

629.1 ’072073-dc20 94-5874 

CI P 

For sale by the U.S. Government Printing Office 

Superintendent of Documents, Mail Stop: SSOP, Washington, DC 20402-9328 
Introduction VI1 

Chapter 1: NASA, Industry, and Technology: 

The Complex Nature of Progress 

I 

Chapter 2: Addressing the New Challenges 

of Air Transportation: 

The TCV/ATOPS Program 

Chapter 3: Revolution in the Cockpit: 

Computerization and 

Electronic Flight Displays 

Chapter 4: A Technology Eclipsed: 

The Microwave Landing System 

and the Dawn of GPS 

Chapter 5: “The Best That We Can DO”: 

Taming the Microburst Windshear 

Chapter 6: Improving Aircraft Systems 

9 

25 

41 

55 

75 

Chapter 7: Improving Aircraft Operations 

Chapter 8: A National Facility 

Conclusion 

Chapter Notes 

Bibliographic Essay 

Illustration Credits 

Glossary of Acronyms 

737 TSRV Specifications 

737 TSRV Flight Log 

Acknowledgements 

Index 

Contents 

Fabric tu@s afixed to the 

wing of the Boeing 737 

testbed aircraft at Langley 

Research Center to 

illustrate ai$ow behavior 

fir high-liJ5 research. 

Introduction 

Lef-Christening of 

thejrst Boeing ,737 at 

the Boeing corporate 

headquarters in Seattle, 

Washington. 

Rigbt- TheJirst flgbt 

of this airplane took 

phce on April 9, 196z 

shown here in Pight test 

at Seattle, Washington. 

his book is the story of a very unique T airplane and the contributions it has made 

to the air transportation industry. NASA’s 

Boeing 737-1 00 Transport Systems Research 

Vehicle was the prototype 737, acquired by the 

Langley Research Center in 1974 to conduct 

research into advanced transport aircraft 

technologies. In the twenty years that followed, 

the airplane 

participated in more 

than twenty different 

research projects, 

evolving from a 

research tool for a 

specific NASA 

program into a 

national airborne 

research facility. It 

played a critical role 

plane, however. Since the airplane played a role 

in such a wide variety of research programs, its 

story also provides an enlightening study of the 

many factors that influence the selection, 

development, and application of new 

technologies. Contrary to popular myth, 

technology neither drives nor sells itself. 

Successfully transferring government-sponsored 

in developing and gaining acceptance for 

numerous significant transport technologies, 

including “glass cockpits,” airborne windshear 

detection systems, data link for air traffic control 

communications, the microwave landing system, 

and the satellite-based global positioning system 

(GPS). Because of its unique research 

equipment, which included a complete second 

cockpit in the cabin, the airplane also served as a 

magnet for joint NASA-industry research efforts 

as well as joint projects with other government 

agencies. 

The chapters that follow offer more than a 

simple, biographical history of a single research 

research into 

operational systems 

or commercial 

products can be 

difficult, but NASA’s 

use of the 737 

showed that 

strategies such as 

cooperative research 

efforts and flight 

demonstration can 

have a significant impact on the acceptance of 

new procedures or technology. 

Ever since 1915, the United States 

government has supported aeronautical research 

and technology because it was considered 

important to the welfare of the nation. Although 

the initial focus was on building and 

maintaining a strong air commerce system and 

national defense, increasing international 

competition in the aerospace market has added a 

new concern. Innovation, research and 

technological advancement are considered 

critical elements to the competitiveness of the 

US. aeronautics industry, which has become one 
of the few remaining fields in which the U.S. still 

has a positive balance of trade. As a result, 

maximizing the effectiveness of governmentsponsored research and the transfer of that 

information to users has become the topic of 

much discussion in recent years. The history of 

NASA’s Boeing 737 Transport Systems Research 

Vehicle offers some valuable insights that can 

make future aeronautical research efforts more 

effective, which, in turn, can help the United 

States maintain that critical competitive edge. 

The first two chapters of this book contain 

background information on the 737 airplane and 

the technology research and transfer process. 

Chapter One provides an overview of the role 

the U.S. government has played in researching 

aeronautical technology and the complex process 

involved in transferring that knowledge to 

industry or other users. Chapter Two covers the 

history of NASA’s Boeing 737 airplane and the 

Langley Research Center program it was 

purchased to support. While these chapters do 

not focus on particular research projects that 

involved the airplane, they provide a historical 

and theoretical context that helps explain the 

challenges the Terminal Configured Vehicle 

(TCV)/Advanced Transport Operating Systems 

(ATOPS) program researchers faced and the 

significance of their accomplishments. 

The next three chapters describe three of the 

most significant research efforts conducted with 

the airplane: electronic flight display technology, 

the microwave landing system/global positioning 

system (GPS) research, and the development of 

an airborne windshear detection system. The 

remainder of the research projects that involved 

the 737 are grouped thematically in the 

following three chapters. Chapter Six discusses 

technology research that was geared toward 

improving systems in individual aircraft; Chapter 

Seven covers research efforts designed to improve 

the operation of aircraft within the air traffic 

control system; and Chapter Eight looks at a 

variety of research projects that used the 7.37 

research aircraft because of its special capabilities. 

the 737 conducted, the story of this unusual 

research vehicle has a human element, as well. 

Although the chapters focus on the research 

Twenty years after the aircraft was purchased, 

quite a few of the people who helped bring the 

airplane home to 1,angley and conducted its first 

research projects are still involved with the 

airplane. The NASA researchers, technicians and 

office personnel who have worked with the 

airplane also possess a fierce sense of loyalty to 

the airplane and pride in what it has done that is 

echoed in the offices of industry engineers who 

worked with the airplane in its early days at 

NASA. One executive at the Roeing Commercia 

Airplane Company even keeps two large prints 

of the airplane and its unique aft research 

cockpit on the wall above his desk. 

It would be easy to lose sight of these 

engineers, technicians, and office workers in 

assessing the airplane’s accomplishments. Indeec 

this book focuses much more on the technology 

the airplane helped to research and why those 
technologies were, or in some cases were not, 

developed into commercial applications. Yet 

without the efforts of those individual people, 

the airplane could not have achieved what it did. 

The TCV/ATOPS program was both technically 

and organizationally challenging, and it was not 

always popular. It involved political pressure and 

deadlines foreign to many NASA researchers. 

The engineers who worked with the TCV/ 

ATOPS program were trying to research and 

transfer aeronautical technology in a new and 

more complex industrial climate, where 

published research papers were no longer 

sufficient to win the support of airlines or 

manufacturers. With hindsight, it is easy to see 

how the program's cooperative research efforts, 

personal connections and flight demonstrations 

helped gain acceptance for many research 

concepts, but the researchers at the time were 

breaking new ground. They had no manuals or 

guidelines on how to successfully transfer 

complex, systems-oriented transport technolorn -. 

to its many users. They had only their own 

experience of what seemed to work, a collective 

creativity and resourcefulness, and a conviction 

that the technology they were researching needed 

to be put to use. These researchers, technicians, 

and office workers may not be as visible as the 

737 airplane or its accomplishments, but the 

program never would have succeeded without 

them. Their names are too numerous to list, but 

in recognition of their years of loyalty, 

dedication, late nights, early mornings, patient 

efforts, and perseverance, this book is 

respectfully dedicated to the NASA professionals 

who made the contributions of the 737 and the 

TCV/ATOPS program possible. 

v . Introduction IX 

LeJi-Langley metal 

wor-ker-s installing 

NACA cowling on a 

Curtiss XF7C-1 Seahawk 

aircrapfor test in 1928. 

For this work, the NAU 

received the 1929 Collier 

Trophy awarded annually 

fir achievement in 

aeronautics in America. 

Right-Model of a 

%oping 737 vi wind 

tunnel test in 1976 

Chapter I 

NASA, Industry, and Technolow: 

The Complex Nature of ProgrG 

nited States government support of U aeronautical research dates back almost to 

the beginning of flight itself. In 1914, as the 

world found itself on the brink of war, only 23 

of the 3,700 airplanes in the world were U.S. 

owned.’ Recognizing the disadvantage at which 

this imbalance put the United States, a rider to 

the Naval Appropriations Act of 19 15 

established the National Advisory Committee for 

Aeronautics “to supervise and direct the 

scientific study of the problems of flight, with a 

view to their practical 

solution.”’ 

time the United States 

government had 

cooperated with industry 

to further technoiogy. 

This was not the first 

I The successful 

development of the 

railroads and modern 

agricultural methods, for I 

government-industry cooperation. Governmentsupported research was to play a particularly 

important role in the progress of aviation, 

however, from the creation of the N.A.C.A. 

engine cowling in the late 1920s and the wide 

variety of N.A.C.A. airfoil designs, to the 

development of jet aircraft.’ 

even eliminate government support for 

aeronautical research led the White House 

example, evolved from d 

In the early 1980s, a proposal to reduce or 

Office of Science and Technology Policy 

(OSTP) to re-examine the government’s role in 

aeronautical research and development (R&D). 

After a year-long study, its final report concluded 

that government support of aeronautics was not 

only still appropriate, but was a critical element 

to the continued economic health of the 

country.’ 

There were numerous compelling arguments 

for continued government support of technology 

development.6 A 1983 report of the White 

House Science Council 

stated that “The ultimate 

purpose of Federal 

support for R&D is to 

develop the science and 

technology base needed 

for a strong national 

defense, for the health and 

well-being of U.S. 

Citizens, and for a healthy 

economy. Certainly, 

national defense had been 

a leading reason for government support of 

aeronautics research since N.A.C.A. was formed 

in 19 15. But President Ronald Reagan’s science 

advisor also noted in 1982 that “aircraft are now 

the dominant common carrier for inter-city 

travel, and the safety and control of that travel 

are a federal responsibiliaty.”’ 

As aeronautical technology became more 

complex and expensive, it was also more difficult 

for individual companies to shoulder the entire 

,r 

I 
financial burden for researching and developing 

new technology and its products. The capital 

investment required to develop a dramatically 

new aircraft could exceed the net worth of the 

sponsoring company. For a manufacturer to be 

willing to invest the money into a new 

technology, it had to have short-term, concrete 

payoffs. Industry did not have the capability or 

incentive to pursue long term or high-risk 

projects, or research areas with uncertain 

benefits. 

Furthermore, firms made decisions on what 

research to pursue based on its value to the 

company, not its value to society. Technologies 

that benefitted society but had less certain 

financial returns for a specific company, 

therefore, needed government support or 

involvement in order to be developed. Safety, for 

example, may be a desirable goal for society, but 

it is a difficult commodity for manufacturers 

to sell.'' 

By the mid-I980s, there was yet another 

argument for continued government support of 

aeronautical research: the diminishing level of 

U.S. industrial competitiveness in the global 

market. In 1986, United States high-technology 

imports exceeded exports for the first time. The 

aerospace industry was one of the only 

remaining fields with a trade surplus, 90 percent 

of which was attributable to the sale of aircraft 

and aircraft parts. Compared to an overall U.S. 

trade deficit in manufactured goods of $136 

billion in 1986, the aerospace industry had a 

surplus of $1 1.8 billion."' But the U.S. lead in 

aeronautics was shrinking, as well. In 1980, the 

U.S. market share of large civil transport sales 

was 90 percent. By 1992, that percentage had 

dropped to 70 percent and was in danger of 

falling even further. The lead in the commuter 

aircraft market had already been lost." Leaders in 

government, industry, academia and the media 

all began to stress that to preserve the U.S. lead 

in aeronautics and, indeed, the U.S. balance of 

trade, the country had to accord a much higher 

priority to aeronautical research and development." 

All of these arguments build a persuasive case 

for continued government support of 

aeronautical research and development. But they 

also illustrate an important point about 

technological progress. From the material 

presented in many traditional textbooks and 

scientific histories, it would be easy to view 

progress as a pure, scientific process that drives 

itself in a cumulative, linear manner. Science and 

technology have often been presented as outside 

the realm of social and political pressures; 

sometimes abused by leaders, but not overtly 

directed by external forces. In recent years, 

however, our view of technological progress has 

begun to change." 

more expensive and complex, research 

institutions have to make choices about what 

technologies to pursue. Those decisions are 

based not only on the scientific promise of a 

specific technology, but on factors such as what 

the government or industry is willing to fund, 

what concepts have the highest probability of 

As research and development efforts become 
leading to a marketable product, and what kind 

of consumer or political pressure exists for 

progress in a particular area.I4 The windshear 

research conducted by the Federal Aviation 

Administration (FAA), NASA, and industry 

throughout the late 1980s, for example, would 

probably not have occurred if it were not for the 

political and public pressure that followed the 

1985 crash of a Delta Airlines L-1011 in Dallas, 

Texas. Industry manufacturers cannot afford to 

research many kinds of technologies themselves, 

and when NASA funding for aeronautical 

research is cut back, many promising ideas may 

be abandoned for no other reason than the 

absence of money to pursue them. 

Progress also does not occur through a 

simple, linear advancement of knowledge and 

capability. As one NASA publication noted, 

“Technological development .. . will have second 

and third order consequences, often unintended, 

beyond the main objective.”” This notion that 

advancements may be accompanied by new and 

unforeseen consequences or difficulties is what 

scholar Thomas P. Hughes called “reverse 

salients.”I6 A breakthrough may solve one difficult problem, but it may also open the door on a 

whole new set of research problems that did not 

exist before the new technology was developed. 

The computerization of many airline cockpit 

functions, for example, greatly expanded the 

capabilities of transport airplanes. But it also 

and created enough significant human-machine 

interface problems that NASA eventually created 

an entirely new research program to help develop 

more human-centered automation.” 

Furthermore, not all concepts that are 

researched are applied to commercial products, 

regardless of their intrinsic technological worth. 

Like progress itself, technology transfer is a 

complex process, affected by numerous external 

factors and decisions. 

The 1958 National Aeronautics and Space 

Act that created the National Aeronautics and 

Space Administration (NASA) specifically 

mandated the agency to “provide for the widest 

practicable and appropriate dissemination of 

information concerning its activities and the 

results thereof.”I8 But as the director of NASA’s 

Technology Utilization office noted in 1963, “In 

this age of automation, there is nothing automatic about the transfer of 

h01 

tion 

inve 

Cal L 

.. 

created an entirely new set of problems that its 

proponents had not anticipated. - 

tion altered the pilot‘s role in thc 

- 

I 

Artist; conception of 

prototype Boeing 737 in 

original colorsf;omfactoly. 

NASA, Industry, and Technology 3 
More recently, one industry publication 

listed some of what it called the “technology 

transfer myths,” which included the idea that 

industry automatically “gobbles up” new technology as soon as it is revealed; that a “better 

mousetrap” is self-evident and doesn’t need 

selling; and that “exciting and valid” technology 

will “automatically” be transferred.”’ 

complicate and influence the transfer of 

technology from government research 

institutions like NASA to industry. Technologies 

that represent a significant change in equipment 

or procedures, for example, may face opposition 

simply because of an inherent tendency on the 

part of people and organizations to resist change. 

Theorists argue that radical new methods, 

technology, or scientific theories require a shift 

in “paradigms,” or accepted truths, in order to 

be adopted, which is a difficult task for people or 

organizations.’” Pilots accustomed to mechanical 

controls may not trust electronic flight 

computers, for example, because their use 

involves a departure from the control principles 

thc pilots were taught and have used successfully 

for years. If a revolutionary new approach or 

technology becomes the norm, it also makes 

individuals’ and companies’ past experience, 

success, and expertise in the outdated method 

irrelevant. Consequently, individuals or 

companies who have achieved significant prestige 

through the use of an existing technology may 

resist replacing it with a new one, no matter how 

The reality is that there are many factors that 

good the replacement is.” 

at risk, and they are often reluctant to bet the 

company on an untried technology. Not 

surprisingly, therefore, new ideas or designs are 

often incorporated fitst by small companies, or 

companies at the fringe of industries, who have 

to take greater risks to gain the necessary market 

share to survive.” Airbus Industries, for example, 

has incorporated more advanced technology into 

its aircraft, including full fly-by-wire controls, 

than the U.S. transport aircraft manufacturers 

have. But the European consortium had more 

motivation to innovate and less to lose than its 

U.S. counterparts. Boeing and McDonnell 

Douglas held such a commanding market 

position that unless Airbus distinguished itself 

significantly in some manner, it would be lost in 

Boeing’s shadow.?‘ 

In addition, there are a number of concrete, 

business reasons why some technologies are not 

adopted by industry. The cost-effectiveness of a 

new concept, for example, plays a critical role in 

whether or not it is ever incorporated into a 

commercial product. To a research engineer at 

the Langley Research Center, success is usually 

measured in terms of technical objectives met. 

Industry, on the other hand, measures innovative 

success in terms of profit gained within a specific 

period of time. A new transport technology 

developed at NASA may work flawlessly and 

may greatly expand an airplane’s capabilities, but 

if it is not going to translate into a profitable 

Large, established companies also have a lot 
investment for a manufacturer or an airline, it is 

not likely to be applied by indu~try.’~ 

External factors that affect the overall 

economic situation of an industry can make cost 

an even greater concern. For example, the 

deregulation of the airline industry in 1978 

made the business much more competitive. As a 

result, accountants became more powerful 

players in purchase decisions, and airlines and 

airframe manufacturers became much more 

likely to reject new technology unless it was 

not even be considered for a new product. 

As technology has become more complex, 

transferring information about new concepts to 

the key people in industry has become more of a 

challenge. For years, the bulk of information 

about NASA research results was transferred 

through written documentation, such as 

technical memoranda, technical papers, articles 

in professional journals, tech briefs, and through 

professional conferences. In fact, a 1992 study of 

NASA’s technology transfer activities found that 

going to show a concrete, short-term profit.*” 

The cost of a new piece of technology is also 

not limited solely to its development or purchase 

price. If too dramatic a change is made in any 

area of a commercial airplane, the design may 

have to be re-certified by the FAA, which can be 

a very expensive process. New cockpit 

equipment may require an airline to retrain all of 

its pilots, causing the carrier to incur substantial 

additional costs. Consequently, a revolutionary 

new design usually has to offer some significant 

savings in order for a manufacturer to consider it 

a worthwhile investment. 

Of course, in order to debate the costeffectiveness of a new technology, industry first 

has to know about and understand what it is and 

what its benefits might be. The information has 

to be communicated effectively not only from 

NASA to industry engineers, but also from those 

engineers to all the decision makers in a 

researchers still often viewed successful transfer 

as writing a report on research results after the 

work was completed.” 

Yet there is a growing consensus that technology transfer efforts stand a much greater 

chance of success if they occur as part of the 

technology development process, through 

personal contact between 

NASA and industry 

engineers, instead of 

through a passive, 

sterile document 

issued after the 

research is 

completed. 

I// 

/- 

, / 51 5. ,/ 

particular company. If any part of that 

communication fails, the technology may 

/’ 

/’ 

Artist? conception of 

Boeing 737painted in 

NASA colors upon 

delivery in 1974. 

NASA, Indu~ty, and Technology 5 
By involving industry earlier in the development process, researchers can help insure that 

the effort is relevant to industry’s needs, and the 

potential users get to observe and contribute to 

the development and progress of a new technology. By the time the research is completed, the 

users already understand it and are in a much 

better position to sell it to the rest of the company decision-makers.2n 

researchers in technology development projects is 

through cooperative research efforts between 

NASA and one or more private companies. This 

approach not only shares the cost burden of the 

research, it also creates a group of professionals 

within the company that thoroughly understand 

the technology and can advocate its 

incorporation into a new product. In addition, 

these arrangements virtually guarantee that the 

research will be seriously considered by at least 

one company. Even if a research project is not a 

joint effort, however, bringing in industry 

representatives for input, evaluation, and 

demonstrations of new technology can be 

invaluable in gaining industry interest and 

support of its use in a commercial application. 

Demonstrations actually can be extremely 

effective in convincing industry to pursue a 

commercial application of a technology . Old 

adages like “A picture is worth a thousand 

words,” and “Seeing is believing,” emphasize the 

power of visual demonstration. Although it 

might take many pages in a technical paper to 

explain exactly how a concept works, a 

One method of involving industry 

demonstration can show, very clearly and 

persuasively, what the technology can do. A 

demonstration can also give a piece of 

technology a critical measure of credibility, 

because it proves the concept will work, at least 

in a test setting. This, in turn, can give industry 

enough confidence to commit to a commercial 

development program.”’ 

The importance of this credibility was 

underscored by H. W. Withington, the former 

Vice President of Engineering at the Boeing 

Commercial Airplane Company, in a letter to a 

manager at the NASA Langley Research Center. 

He emphasized that “laboratory development 

has great appeal and usually gets substantial 

government support. However, ... the attainment 

of credibili ty... is (also) an important national 

issue. It is during this second phase that a 

technical concept achieves a state of readiness, 

validation and credibility such that private 

industry and financing can assume the attendant 

risks. ” “I 

Giving industry information about and 

confidence in a new concept is still only one 

step, and one factor, in the technology 

application process, however. Even if industry 

representatives are included at an early stage in 

the research, there is continual contact and 

communication between government and 

industry representatives, and the technology is 

persuasively demonstrated, a concept still may 

not be incorporated into a commercial 

application. By the same token, some research 

transferred less perfectly may be adopted 

v .. 
immediately by industry if, for example, federal 

regulations mandate that it be incorporated into 

forthcoming products. 

Yet although it can be a complex and often 

frustrating process, successhl technology transfer 

is a critical step in advancing America’s 

aeronautical industry. In early 1993, NASA 

Administrator Daniel S. Goldin stated that “the 

transfer of our valuable technology ... must be 

proactively sought and given the highest 

priority.”” 

on technology transfer within the aeronautics 

and space agency. But for the engineers, pilots, 

researchers and staff who worked with the 

Terminal Configured VehiclelAdvanced 

Transport Operating Systems program at the 

Langley Research Center in Virginia, Goldin was 

simply restating a philosophy they had lived with 

for the past 20 years. 

Research Center created the Terminal 

Configured Vehicle research program and 

successfully argued for the purchase of a Boeing 

737 research aircraft in which to develop, test, 

and demonstrate advanced technologies for use 

by the commercial air transport industry. Over 

the course of the next two decades, the airplane 

was involved in more than 20 different research 

projects, most of which were focused on 

improving the efficiency, capacity, and safety of 

the air transportation system. Some of the 

Goldin’s words marked a renewed emphasis 

In 1973, a group of engineers at the Langley 

impact on air transport operations. Others, 

equally worthy from a technical point of view, 

have yet to be applied. 

projects, with widely differing results and 

applications, the story of NASA’s 737 airplane 

offers a unique opportunity to examine the 

forces and factors that influence the development 

and application of new technology. 

Furthermore, although the Langley engineers did 

not set out to explore creative methods of 

technology transfer, their experience with the 

airplane and its numerous research projects 

contains some important lessons about how 

technology transfer can be accomplished, and 

the difference a facility like the 737 research 

airplane can make. 

Because it played a role in so many different 

FA F 

technologies were developed into commercial ,/ 3 13 

applications and have had a significant , .’ 

,’ 

Artist; conception of 

Boeing 737 in present 

NASA colors. The 

yellow tail stripe and the 

FAA logo were removed 

and new NASA 

lettering was used 

NASA, Industry, and Technology 7 
. _. 

' I" 

. p. 
Chapter 2 

Lej-Airliners waiting 

in linefor take-08 

illustrate the airport 

congestion that prompted 

the formation of the 

Terminal Configured 

Vehicle (TCV) research 

program. 

Right- The 737 

simulator at Langley 

Research Center. 

Addressing the New Chal1ene;es 

of Air Transportation: 

The TCWATOPS Program 

w en Neil Armstrong landed on the moon in July 1969, it capped off a tremendous 

national effort that had absorbed most of 

NASA’s attention and resources throughout the 

1960s. As the Apollo program wound down, 

however, it created both an opportunity and a 

need for NASA to re-evaluate its activities and 

direction. A number of people within the 

agency, including acting administrator Thomas 

One of the members of the DOT-NASA 

study team was Barry Graves, the head of the 

Flight Instrumentation Division (FID) at 

NASA’s Langley Research Center. In addition to 

his NASA duties, Graves was also a private pilot 

and had a keen interest in the problems facing 

civil aviation. As work progressed on the DOTNASA Civil Aviation Research and 

Development (CARD) Policy Study, Graves also 

0. Paine and Deputy had a small group of 

Administrator George people within his 

M. Low, felt that division evaluating 

aeronautics should now ways Langley might 

be able to contribute 

to air transportation 

research. At the same 

receive greater 

attention and support. ’ 

Congress also had 

begun to feel that the time, John P. “Jack 

government needed to Reeder, a famous 

focus more on NASA test pilot at 

furthering aeronautical Langley who was 

technology. A report another staunch 

issued by the Senate supporter of civil 

Committee on aviation, was 

Aeronautical and Space Sciences in January 

1968 emphasized the need for a national policy 

on aeronautics research and development. The 

report also recommended that NASA and the 

newly formed Department of Transportation 

undertake a joint study to evaluate the problems 

facing civil aviation and the potential benefits 

that might accrue from government support 

of Research and Development (R&D) in 

those areas.’ 

formulating his own proposals for research to 

improve air transport operations.’ 

When the results of the CARD study were 

released in March 1971, the report concluded 

that a healthy civil aviation industry and 

transportation system provided a variety of 

significant benefits to the nation. Consequently, 

the study recommended, the federal government 

should take an active role in developing a 

national aviation policy and conducting R&D 

9 
Early supporters of the 

TCVIAdvanced 

Transport Operating 

Systems (A TOPS) 

Program. Le$ to right: 

Edgar M. Cortrigbt, 

Langley Research Center 

Director 1968-1975; 

John Reeder, research 

program director; and 

Oran W Nicks, Langlq 

deputy director, during 

arrival of the 737 in 

1974. 

to benefit civil aviation. The report also outlined 

priorities for these R&D efforts. The top two 

concerns were aircraft noise and congestion in 

the terminal, or airport, area.4 

developing for some time. By the late 1960s, air 

travel was no longer the privilege of the elite. As 

it became an accepted and highly popular form 

of transportation, however, delays were 

becoming commonplace. An example often used 

by the researchers at Langley was that in 1959, a 

propeller-driven Lockheed Electra took 40 

minutes to fly from Norfolk, Virginia to 

These problems had actually been 

Washington, D.C. In 

1973, a Boeing 727 1 jet capable of flying 

twice as fast took 45- 

55 minutes to make 

that same trip 

because of increased 

air traffic and 

terminal congestion 

problems.’ 

also increased the 

noise level around 

commercial airports, resulting in community 

opposition to additional air traffic or the 

building of new airports. In addition to driving 

research on quieter engines, this meant that there 

was an even greater need to make the most 

efficient and noise-sensitive use of the country’s 

existing airports.6 

was released, President Richard M. Nixon’s 

Office of Science and Technology (OST) asked 

NASA to submit proposals on how NASA could 

contribute to research and development in the 

civil aeronautical sector. One of the six internal 

task groups that were formed to develop 

proposals looked specifically at air 

transportation research and development. In less 

than two months, the proposals were submitted 

and the OST asked NASA to develop its air 

transportation proposal into a detailed program 

and prepare to begin research. The task was 

given to the Langley Research Center.’ Langley 

was the agency’s oldest field organization, 

-- 

The advent of jets 

9 

A couple of months after the CARD study 

founded in 19 18 specifically to conduct 

aeronautical R&D. 

Although his proposals had been turned 

down by the Aeronautics Steering Committee in 

the past, Jack Reeder presented his ideas on 

improving airspace utilization to the group 

working with Barry Graves to develop the 

detailed air transportation research program. 

Reeder’s ideas fit extremely well with the plans 

being formulated by the FID team, and the two 

were incorporated into a program plan that 

became the Terminal Configured Vehicle (TCV) 

program. The original name was actually the 

Terminal Configured Vehicle & Avionics 

program, but the “avionics” was soon dropped.8 

The TCV program was an unusual research 

project for Langley. Instead of just looking at a 

single airfoil or aircraft component, the TCV 

program also included research into the pilot/ 

airplane interface and the airplane’s interface 

with the air traffic control system. This was a 

much broader scope of work, involving more 

branches, divisions, disciplines and directorates 

than the typical Langley research effort. But as 

the example of the Lockheed Electra and the B727 illustrated, the problems facing civil air 

transport had grown much more complex. In the 

1920s, the development of a NACA engine 

cowling alone was able to make a significant 

impact on the efficiency of air travel. By 1970, 

even the most aerodynamically efficient airplane 

could not overcome the delays imposed by trafic 

congestion in the terminal area. The challenge 

had become a systems problem, and it required a 

system-oriented solution. 

to conduct research into advanced technology 

for Conventional Take-Off and Landing 

(CTOL) aircraft, 

The broad goals of the TCV program were 

. . . to provide improvements in the airborne 

systems (avionics und air vehicle) and operational 

flight procedures for reducing approach and lunding 

accidents, reducing weatber minima, increasing air 

trafic controller productivity and airport and 

airway capaciy, saving fiel by more eficient 

terminal area operations, and reducing noise by 

operational procedures. ’ 

IO Airborne Trailblazer 
Specifically, the TCV program wanted to 

look at items such as curved or non-standard 

approach paths for noise abatement and 

improved airport acceptance rates; cockpit 

displays of trafic information; profile and timebased navigation, which would use a computer 

to calculate an optimum fuel-eficient flight plan 

that would deliver an airplane to its touchdown 

spot +/- five seconds to allow closer spacing of 

aircraft. Other planned experiments would look 

at data links, high-speed runway turnoffs, and 

optimum uses of the new Microwave Landing 

System (MLS) that the Federal Aviation 

Administration (FAA) was developing." 

1 

Aquiring a Research Aircraft 

Since the focus of the work was to improve 

operations for commercial transport airplanes, 

the researchers at Langley argued that the 

program needed to include flight tests with a 

transport-size CTOL aircraft. The only large 

aircraft owned by NASA were a C-141A and a 

Convair 990 located at the Ames Research 

Center in California. The cost of using one of 

these four-engine airplanes for a 6-8 year 

research program was too high, however, and all 

the other NASA-owned airplanes were too small, 

or lacked the capabilities necessary to carry out 

the TCV research. Langley personnel working 

on the project also believed that in order for the 

results of their research to be accepted and used 

by the air transport industry, the technology had 

to be tested and developed on a commercial 

transport class airplane. 

The best candidate for a test airplane 

appeared to be either a DC-9 or a Boeing 737, 

since both had adequate room and capability as 

well as manageable operating costs. The Boeing 

737 was Langley's number one choice, however, 

since it had a slightly wider fuselage and an 

advanced, high-lift flap system. Money, 

The NASA 737 research 

program was built on 

improving aircrafi systems 

such as these used around 

airports. 

Addressing the Ncw Chn f fengcs ofAir Tranportution I1 
however, was extremely tight. The market value 

of a used 737 in 1972 was about $3.5 million, 

but the Boeing Company had one particular 737 

that its sales people said they might be willing to 

sell for substantially less." 

prototype 737-100, used for FAA certification 

tests on the model. The Dash 100 model, which 

had a length only one foot longer than its 

wingspan, was nicknamed "Fat Albert" because 

its shape was so stubby compared to most 

airliners. The prototype flew for the first time on 

April 9, 1967, and had only 978 flight hours on 

its airframe. Since the first order for 737-100s 

was from Lufthansa Airlines, Boeing had 

designated the prototype as PA-099: PA for 

Lufthansa, and 099 as the last one in a block of 

100 aircraft numbers Boeing had reserved for the 

airline. The prototype was never sold, however, 

because it was only certified for experimental 

use. With all the holes, wiring and other 

modifications that were made to the airplane for 

certification tests, bringing it up to the standards 

of a commercial transport airplane would have 

been too expensive. Boeing used the airplane for 

a few additional flight tests and then simply set it 

aside. ' 

In fact, when the Langley engineers first 

travelled to Seattle to look at the plane, it was a 

dismal sight. The engines had been removed, 

and the airplane was sitting at the end of the 

ramp at Boeing's facility in Renton, Washington, 

with cement blocks hanging off the engine 

pylons to keep the airplane from falling on its 

tail. The interior had been stripped out, and 

where the cockpit instruments should have been, 

there were only bundles of wire dangling from 

the remains of a panel. Nevertheless, the plane 

had several characteristics that appealed to 

NASA. First, Boeing was willing to bring it back 

to flightworthy status, complete with overhauled 

engines, and sell it to NASA for only $2.2 

million. Second, while the modifications and 

special instruiiientation wiring and plumbing in 

the airpl:ine were usclcss for an airlinc, they 

made PA-099 more suitable as a research 

airplane." 

The Boeing aircrafi was the original 

The Boeing plane also had one other 

significant advantage. Boeing had been awarded 

the contract to build the U.S. Supersonic 

Transport (SST) aircraft, which included 

advanced avionics, displays and flight control 

systems. The program had become very 

controversial, however, with substantial 

opposition from communities and groups who 

were concerned about the environmental impact 

the plane would have. Finally, on March 24, 

197 1, Congress voted to cancel the SST.I4 But in 
an effort to keep all the technology development 

efforts for the plane from being wasted, Congress 

authorized Boeing to do a small amount of 

follow-on research in a number of technology 

areas. Two of these areas were advanced 

electronic displays and digital flight controls. 

Boeing had contracted with the Department 

of Transportation (DOT) to develop the SST 

Advanced Digital Electronic Displays (ADEDS) 

and the Automatic Guidance and Control 

(AGCS) digital flight control system to a point 

where they could be flight tested. The Boeing 

plans called for very limited flight testing of the 

experimental equipment, after which the 

equipment would be returned to the DOT.” 

When the Langley engineers approached 

Boeing about a 737, however, they and Boeing 

both realized the potential benefits of integrating 

this advanced equipment into the prototype 737 

as a research airplane for NASA. NASA would 

get the opportunity to experiment with the most 

advanced display and flight control technology 

available, and Boeing would get a chance to test 

the equipment in a specially equipped research 

airplane with an extensive data-gathering 

capability. 

The DOT, in the fall of 1971, had asked 

NASA to support the Boeing follow-on tests of 

the SST electronic displays.’6 To put the DOTowned display and flight control equipment in a 

NASA airplane on a permanent basis, however, 

would require a cooperative agreement between 

NASA and the FAA. 

While cooperative efforts between the two 

government agencies were not unheard of, the 

separate roles and responsibilities of the two 

organizations with regard to national problems 

in aeronautics and civil aviation were not clearly 

defined. The agencies also had different 

mandates. NASA was a research agency, charged 

with furthering new technology. It did not have 

to worry about certifying production equipment, 

or regulating its operation. The FAA’s primary 

responsibility, on the other hand, was to keep 

the national air traffic system operating smoothly 

and safely on a day to day basis. Consequently, 

the two agencies’ research priorities and 

approaches often differed. 

There were some people in the FAA who 

thought that NASA should concern itself only 

with airplane technology and should leave issues 

such as more efficient operating procedures for 

the terminal area to the FAA. The problem was 

that the FAA had fewer resources to devote to 

such research. NASA’s aeronautics research 

budget and personnel typically exceeded that of 

the FAA’s R&D department by a magnitude of 

at least 10. At the same time, NASA research in 

Flight deck of the Jirture 

NASA Langlq, 737 

testbed aircraft as it 

appeared after completion 

of Boeingprototype tests 

and before re&rbishment 

for NASA. Its engines had 

been removed and the 

interior, including the 

instrument panel, had 

been stripped. 
A typical map display 

using Cathode hy Tube 

technohgy. 

new air transportation technology and 

procedures would not have any practical impact 

without the FAA’s involvement on some level, 

since the FAA had to approve any changes in air 

transport equipment or operations. But while it 

may have made sense for the agencies to work 

together on the problems, there were still areas of 

tension over turf, priorities, and working 

relationships that persisted long after a 

cooperative working agreement was signed.” 

In May 1973, a cooperative agreement 

between NASA and the FAA was reached. In 

exchange for putting the SST technology in the 

new NASA airplane, NASA agreed to allow 

Boeing to use the plane first to conduct the 

DOT flight tests of the SST equipment. After 

that, the FAA would be entitled to up to 

25 percent of the aircraft’s flying time for its 

own research projects. 

On July 26, 1973, NASA officially 

purchased Boeing’s prototype 737- 100 aircraft. 

Boeing spent most of the next 10 months 

outfitting the aircraft to NASA’s specifications 

and completing the DOT flight tests.’” Wearing 

its new tail number of N5 15NA, the airplane 

finally arrived at Langley to begin its remarkable 

career as NASA’s Transport Systems Research 

Vehicle (TSRV) on May 17, 1974.’O 

Airborne Trailbkrzpr 

Aircraft Equipment and Research Systems 

Without a doubt, NASA’s new 737 was a 

one-of-a-kind airplane. In addition to a 

conventional forward flight deck, Boeing 

modified the airplane with a second, 

experimental cockpit in the forward part of the 

main cabin that contained the advanced SST 

avionics. The af? flight deck (AFD) was enclosed 

in a full-size fiberglass duplicate of the 737’s 

front cockpit exterior that left just enough room 

for a small passageway to one side. A second 

fiberglass cab was used to build a high-fidelity 

fixed-base ground simulator that replicated the 

aft flight deck. The simulator, run by a highspeed Control Data Corporation CDC-6400 

mainframe computer, allowed experiments to be 

tested and developed through real-time 

simulation on the ground before they were put 

on the airplane. 

NASA flight test programs usually divided 

an aircraft’s cockpit into two parts and installed 

any experimental equipment on one side, leaving 

a safety pilot on the other. The TCV researchers 

wanted the ability to evaluate new transport 

technology in a realistic, two-crew environment, 

however, so the 737 was outfitted with the 

complete second cockpit. For the NASA research 

flights, the aft cockpit was equipped with four 

monochrome cathode ray tube (CRT) displays. 

The pilot and copilot positions had both a 

primary flight display (PFD), and a navigation, 

or map, CRT display in front of them, installed 

above a Control and Display Unit (CDU), 

which was the pilot’s interface with the 

navigation computer.*’ 

In order for the pilots to be able to see the 

full displays, the aft flight deck was equipped 

with two individual handles that came out of the 

instrument panel instead of conventional center 

control yokes. Sidestick controllers, like those 

eventually installed in the Airbus A-320 airliner, 

were ruled out because they were a more 

dramatic departure from conventional yokes, 

and the researchers wanted to keep the 737’s 

cockpit at least somewhat familiar to airline 

pilots. Although they were referred to in 

technical papers as “Panel Mounted 
Controllers,” the dual handles were dubbed 

“Brolly Handles” by a British engineer who 

worked on the project, because their shape 

reminded him of an umbrella handle, or 

“brolly,” as it is sometimes called in England. 

The instrument panel of the aft flight deck also 

included electromechanical engine instruments 

and a Boeing Advanced Guidance and Control 

Panel (AGCS), which was used to select different 

levels of automatic or manual flight control. 

Because the focus of the TCV research was 

flight operations under Instrument Flight Rules 

(IFR), the complete lack of visibility from the aft 

flight deck was not considered a problem. The 

FAA, on the other hand, wanted its pilots to be 

able to try the experimental SST equipment in a 

less severe environment, where they could still 

use outside visual cues. So the 737 was also 

wired to allow one set of the displays, one CDU 

and the AGCS Panel to be installed on the right 

side of the forward flight deck. Instead of brolly 

handles, however, the right-hand control column 

of the 737 was simply shortened to keep the 

yoke from obscuring the displays, since the FAA 

wanted to keep the configuration as 

conventional as possible. This “FAA” 

configuration, however, was only used once, for 

baseline testing of the SST equipment at the 

FAA’s technical center in Atlantic City, New 

Jersey, in the fall of 1374.” 

The airplane was also equipped to use the 

SST equipment in a third, “split” configuration, 

which would have put one set of just the displays in 

the right-hand side of the forward flight deck for 

monitoring by a safety pilot. This configuration 

was never actually used, however. 

In all the configurations, control inputs from 

the experimental systems were processed through 

the SST program’s digital flight control 

computer, which then interfaced with the 

airplane’s autopilot. Because the computer relied 

on the autopilot system to actually drive the 

control surfaces, the aft flight deck was restricted 

to half the control authority of the forward 

cockpit, which used a conventional 737 powered 

control system. 

This arrangement allowed experiments to be 

conducted in the aft cockpit while safety pilots 

rs 

B 

monitored all the operations from the forward 

flight deck. This was an extremely valuable 

capability, as it allowed new and unproven 

technologies to be tested in an actual flight 

environment while maintaining an acceptable 

level of safety. It would probably have been far 

too risky, for example, to include autolands in 

the testing of the MLS curved path approaches if 

the plane did not have safety pilots up front who 

could see outside, monitor the progress of the 

approach, and take over if necessary. And yet the 

actual completion of those autolands was one of 

the things that made the MLS demonstrations 

so effective. 

The safety pilots could take over control of 

the airplane simply by pushing one of two 

buttons or operating a trim system switch, and 

the pilots in the aft flight deck could give 

control back to the forward flight deck by 

pushing a disconnect button. Annunciation 

lights in both cockpits would light up with any 

change in command, and the pilots would also 

verbally noti@ each other of the switch over the 

airplane’s intercom system. Status messages and 

requests from the aft flight deck were monitored 

by the safety pilots on a “Control and 

Command” panel on the top of the front 

instrument panel. Gear and speed brakes, for 

Tightly packed 

electronics racks 

required to conduct 

research on the Boeing 

737 aircraj. Each 

pallet had a row of 

three seatsfor 

researchers. Note the 

aftpight deck partially 

shown in the center 

background. 
0 

N 
system provided computerized navigation 

functions, which controlled the airplane’s flight 

path. The third sub-system operated the 

electronic flight displays in the aft cockpit. 

three systems consisted of triply redundant 

General Electric (GE) ICP 723 flight control 

computers, a General Electric 70 1 digital display 

computer, and a Litton C-4000 navigation 

computer. The aircraft also incorporated a triply 

redundant Litton LTNS 1 Inertial Navigation 

System (INS). The General Electric computers 

The original experimental equipment for the 

were all prototypes, developed specifically for the 

SST program. The ICP 723 computers were 

actually not fully digital but something called 

step between analog and digital systems. *’ 

was that it was never intended to be operational 

in an airplane for a long period of time. It had 

been designed to operate for only one ninety-day 

test. Yet NASA ended up flying the display 

computers, for example, for 12 years. The 

maintenance headaches this caused were 

complicated further by the fact that the 

equipment was what the NASA technicians 

termed “brassboard,” or only one step better 

than the crudely connected systems electronics 

researchers would initially test in a lab. There 

were no maintenance manuals and no 

replacement systems. If a problem developed, it 

sometimes took phone calls to six or more GE 

engineers who had helped design the system as 

well as scanning pages of blueprint drafts to 

figure out how it could be fixed. Then the 

problem had to be troubleshot down to the level 

of individual parts on the circuit cards, because 

there were not even any spare circuit cards. 

Since there were no spares in a lab to use to 

troubleshoot problems, the crew in charge of the 

experimental systems had to use the airplane as 

their lab. During flight test periods, this meant 

that repairs generally had to be made at night, so 

the next day’s experiments could still be flown. 

Amazingly, although some flights had to be 

cancelled, the late hours and the resourcefulness 

of the Langley personnel who worked on the 

equipment kept the airplane from ever missing a 

major research program. 

Fortunately, the equipment was upgraded 

substantially over the years. The first change was 

made in 1976, when the GE ICP 723 computers 

were replaced with triply redundant GE 703 

whole-word computers, which were full digital 

systems. In 1983 the GE 703 computers were 

replaced with a single Norden 1170 flight 

control computer. The single string flight 

control system was considered acceptable because of the back-up provided by the conventional controls in the forward flight deck. The 

‘<. incremental word computers; an intermediate 

The biggest problem with the GE equipment 

The NASA 737 on the 

ramp during flight tests 

I992 as lightning strikc 

the background. 

in 

?s ir 
18 

Norden 1170 also replaced the Litton C4000, 

giving the airplane its first complete flight 

management computer. 

The system architecture of the experimental 

system was also changed in 1983 to a Digital 

Autonomous Terminal Access Communications 

(DATAC) data bus, invented by Boeing engineer 

Hans Herzog. Instead of requiring dedicated 

buses and connections for each item researchers 

wanted to get into or out of the computer, the 

DATAC system was a “broadcast” bus. All the 

information was broadcast in sequence down a 

single twisted pair of wires, and any station that 

needed information could simply connect to the 

bus and collect whatever data it required. The 

DATAC system also used magnetic coupling 

instead of hard connections, which made adding 

or changing experimental equipment vastly 

eas le r. 

In 1986, the original GE 701 display 

computer was finally replaced with a second 

Norden 1170, and new SperrylHoneywell color 

displays were installed. There was some debate 

among Langley engineers as to what size display 

to buy, because the only “off the shelf’ displays 

available were small, 5” x 7” “B-size” CRTs. 

Sperry/Honeywell was in the process of 

developing bigger 8“ diameter “D-size” displays, 

but they were not fully tested yet. However, the 

Langley managers decided that since the bigger 

displays were going to be the wave of the future 

in transport airplanes, they would take the risk of 

ordering them for the 737. Eventually, the aft 

flight deck was equipped with eight of the color 

monitors.” 

Two years later, the Norden 1170 flight 

management computer was replaced with a 

Digital Equipment Corporation (DEC) 

MicroVax I1 computer, which was faster, 

smaller, cheaper, easier to cool, and took less 

power to operate. At the same time, the brolly 

handles on the left side of the aft flight deck were 

replaced with a McFadden side stick controller. 

In 1000, ;i second 1)FX: MicroVax I1 

coniputcr took the place of the Norden 1 170 

display computer, and second side stick 

controller was installed. The most recent 

upgrade to the system was the installation of new 

computer cards in the MicroVaxes that equipped 

the computers with a new processor. The 

upgrade changed the computers into MicroVax 

IVs and doubled their speed.” 

experimental equipment were necessary to keep 

pace with the rapid developments in computer 

technology over the last 20 years. The 

equipment has not been the only aspect of the 

program to change, however. The organizational 

structure and the level of support the program 

has enjoyed have both varied widely over the 

years. 

The almost continuous upgrades in 

Program Organization 

By its very nature, the TCV program was 

destined to be an organizational challenge. 

Because its goal was to look at an entire system, 

instead of a single aerodynamic or electronic 

component, it required the expertise and 

cooperation of a wide variety of people, both 

inside and outside of Langley. At first, the 

Langley management was not even sure under 

which directorate the program should go.”’ For a 

very brief time during its initial formulation, the 

program was under the supervision of both the 

Aeronautics and the Electronics directorates. The 

problems inherent in that divided structure, 

however, led the center management to put it 

under the sole control of Electronics in May 

1973.’ The program was put 011 the san~ level 

as a division office, reporting directly to the head 

of the Electronics directorate, and Jack Reedcr 

was made the program chief. 

Even then, the organization was far from 

simple. Langley leadership had traditionally tried 

to avoid separating researchers from colleagues in 

their discipline, because it was felt that such a 

move would cause the researchers to fall behind 

in their field and would hurt the strength of the 

different research disciplines. ‘h Consequently, all 

the people involved in the TCV program except 

a small core of program office personnel stayed 

administratively attached to their different 

branches, divisions and directorates. Their work 

priorities were decided by the program office, 

but their performance evaluations and pay raises 
were given to them by their administrative 

supervisors. This kind of “matrix” organization 

offered a number of advantages and had been 

used often throughout Langley’s history. It also 

had some inherent drawbacks, however. 

A matrix arrangement allowed research 

programs to benefit from the contributions of 

highly skilled specialists that the center could not 

afford to assign exclusively to one particular 

project. When the TCV program started, for 

example, Langley had two or three worldrenowned specialists in microwave antenna 

design. Antenna design was critical for a number 

of aircraft experiments, including the use of the 

microwave landing system. But it was a highly 

specialized field, and the center could not 

support a large number of researchers with that 

concentration. Consequently, if each one of the 

design researchers had been assigned full-time to 

a different project, the antenna design discipline 

at Langley would have ceased to exist. Without 

the benefit of a central discipline and daily 

contact with their colleagues, the individual 

researchers would have had a difficult time 

staying up with new developments in the 

antenna design field, and their work itself would 

undoubtedly have suffered, because it would 

have been more difficult for their peers to review 

and contribute to their research as it progressed. 

A matrix structure, on the other hand, left the 

disciplines intact and allowed them to support a 

number of different research projects and 

programs. 

While a matrix organization had a lot of 

advantages from a research perspective, however, 

it was extremely difficult to manage or work 

within from an administrative standpoint. The 

program managers had no direct line authority 

to enforce anything, and if a researcher’s 

administrative supervisor had different ideas or 

priorities than the program managers, the 

researcher could be caught in a very 

Cutaway model of the 

Boeing 737 usedfnrflighi 

research showing its a8 

cockpit and the location 

of various research pallets. 
uncomfortable position. Program work deadlines 

and priorities had to be enforced primarily by 

persuasion, which meant the success of a research 

program depended partly on the personalities of 

its managers. Accomplishing tasks in this kind of 

environment took a lot more effort and finesse 

than a straight vertical organization would have 

required. The Monday morning TCV program 

coordinating meetings were legendary at the 

center for the heated arguments that erupted 

among project personnel, and many people 

involved in the early days of the program still 

believe that a matrix structure is an 

organizational nightmare.'" 

out a better way to make a broad-based effort 

like the TCV program work. Managers in the 

Flight Systems directorate, under which the 

program operated after 1985, once studied what 

it would take to put all the researchers who 

supported the program in one administrative 

The problem was that nobody could figure 

The NASA Boeing 737 

Jlying over Langlq, 

Research Center. 

organization. They discovered they would have 

to remove so many researchers from other 

directorates and research disciplines that it would 

severely handicap the center's other research 

efforts. The TCV program simply drew from too 

many different areas for it to operate as a 

straight, vertical organization."' 

In addition to this challenging matrix 

organization, the TCV program initially had to 

interface with a Flight Experiments Working 

Group, as well. The group was made up of 

representatives from different NASA centers and 

the FAA and was supposed to help select 

appropriate experiments for the TCV office to 

conduct." This structure was soon changed, 

however, to give responsibility for approving 

experiments to the program and directorate 

management. 

The TCV program also included a 

contingent from the Boeing Commercial 

Airplane Company from 1974 until 1979. The 

20 Airborne Trailbhzr 
initial plan was for a team of technicians and 

engineers to spend a year at Langley, orienting 

the NASA personnel to the 737 airplane and its 

advanced equipment. At the end of the year, 

however, NASA extended its contract with 

Boeing to keep its office at Langley open for 

what turned out to be another four years. At one 

point, Boeing had 70 employees working on the 

TCV program at Langley. Although this kind of 

long-term, side-by-side working relationship 

with industry was unusual for NASA, the 

arrangement proved to have a tremendous 

payoff. In addition to the support the Boeing 

engineers provided for the TCV program in its 

early years, several of the young engineers who 

cut their teeth on the TCV program returned to 

Boeing to head up various departments working 

to design the 757/767 airplanes. The Boeing 

engineers not only knew about the new 

technology NASA was researching; they had 

worked with it themselves, watched its progress, 

and thoroughly understood the potential benefits 

it could offer. As a result, they were able to help 

convince others within the company that the 

technology was worth considering. In addition, 

the personal relationships the Langley researchers 

formed with the Boeing engineers improved 

communication channels and gave NASA easier 

access to key decision-makers within Boeing. 

Both of these factors played an important role in 

Boeing’s decision to incorporate some of the 

technologies in its new aircraft designs.’* 

shifted from a division level to a branch level, 

and put under the Control Theory and Flight 

Management division of the Electronics 

directorate. By June 1982, the name had been 

shortened to the Flight Control Systems division 

and put under the management of Dr. Jeremiah 

F. Creedon. The TCV name was changed, as 

well, to the Advanced Transport Operating 

Systems (ATOPS) program. The new name was 

chosen to reflect the program’s renewed 

emphasis on air transportation system issues, 

rather than individual airplane technologies. 

directorate into two separate organizations. The 

new directorate was called Flight Systems, and 

At the end of 1981, the TCV program was 

In July 1985, Langley split the Electronics 

the ATOPS office was moved to a division level 

within that directorate. The creation of the 

Flight Systems directorate also helped the matrix 

operations of the ATOPS program somewhat, 

because it concentrated more of the people 

involved with the program in a single 

administrative structure. In an effort to simplify 

the matrix operations even further and to 

encourage greater involvement in the ATOPS 

program on the division level, the ATOPS office 

was moved back to a branch level under the 

Flight Management division in 1991, although it 

remained in the Flight Systems directorate.” 

The financial, institutional, and industry 

support the program received over its 20 year 

lifespan also varied greatly. At times, such as 

during the U.S. MLS demonstrations in 1976- 

78, and in the recent wind shear detection flight 

tests, the program was well hnded and had the 

open support of NASA headquarters, the FAA, 

and industry. Funding was usually a struggle, 

however, and on several different occasions, the 

program came very close to being cancelled 

altogether. 

program began to refocus on broader air 

transportation system problems rather than 

individual aircraft technology, the tensions over 

turf and areas of responsibility between NASA 

and the FAA flared up once again. To save a 

measure of funding for the program and make it 

less controversial, William D. Mace, head of the 

Electronics directorate at Langley, agreed to take 

on a program to simply gather data on MLS 

operations using the conventional, 

electromechanical instruments in the forward 

flight deck. That MLS Service Test and 

Evaluation Program (STEP) was the only flight 

test work conducted by the 737 from July 1982 

to March 1983, but it kept the airplane flyingT4 

In the mid- 1980s, the program was 

endangered once again. This time, the funds 

were being pulled by NASA headquarters from 

various aeronautics programs to permit greater 

emphasis on high speed research. The Langley 

Research Center management was very 

supportive of the ATOPS program, however, 

and fought successfully for its survival. Soon 

In the early 198Os, for example, as the 
after that, the ATOPS program almost became a 

victim of the Gramm-Rudman amendment, 

when NASA found itself facing severe budget 

cuts across the board. The program elements 

were cut to the bare bones, but the airplane was 

kept flying. 

Recently, the program has begun to enjoy a 

period of renewed support. The new NASA 

Administrator, Daniel S. Goldin, and President 

Bill Clinton are both strong advocates of 

government support for the aviation industry, 

and the ATOPS program has been given 

approval to embark on a huge new initiative 

called Terminal Area Productivity (TAP). 

Interestingly enough, the goals of TAP are 

almost identical '5 to the goals of the original TCV 

program. 

The TCVlATOPS program has already 

made a number of highly significant 

contributions to air transportation technology. 

Many of the challenges that NASA and the 

DOT identified in the early 1970s still exist, 

22 Airborne Trfiilblrrzer 
however. In addition, advances in technology 

have created new opportunities for research that 

did not exist 20 years ago. The demands on the 

national airspace system have grown and 

changed, and the U.S. civil aviation industry 

now faces more foreign competition than it did 

in the early 1970s. 

In retrospect, perhaps the most surprising 

aspect of the TCV/ATOPS/TAP program is not 

that the work is still continuing, or that the goals 

have remained the same, but that the original 

program pian only called for the research to last 

five or six years. The contributions made by the 

TCV/ATOPS program have certainly been 

important steps forward. But unlike the 

challenge of putting an American on the moon, 

the goal of improving air operations in crowded 

airport areas is not a finite, achievable target. It is 

a continuing, dynamic process that will always 

have room for new research and ideas. 

Chapter 3 

Revolution in the Cockpit: 

Leji- Theflight deck of 

a 757/7Gz incorporating 

systems that the NASA 

737 aided in research and 

development. 

Right- The control tower 

at Wallops Flight Faciliq. 

Many of the NASA 737 

aircrafi research activities 

have taken place at this 

installation. 

Computerization and Electronic Flight Displays 

T en the Terminal Configured Vehicle (TCV) program began in 1973, the air 

transport industry was facing some dramatic 

changes in aircraft design and operation. The 

development of the computer driven cathode ray 

tube (CRT) made a whole new kind of aircraft 

display possible, and the advancement of digital 

technology was preparing to revolutionize 

aitcrafi operations. 

By the early 1970s, 

digital technology was ;B 

incorporate updates in capability through simple 

computer sofnvare changes. As a result, digital 

systems were predicted to reduce maintenance 

costs and equipment weight and volume as 

much as 25-40%. Digital technology also offered 

the opportunity to control many aircraft 

guidance and navigation functions by computer, 

allowing much more precise and fuel-efficient 

beginning to be considered 

reliable enough to be 

incorporated into 

commercial transport 

1 /- aircraft. Wide body airliners 

had already begun to use 

digital equipment for 

numerous subsystems, and 

the next generation 

transport airplanes were 

digital techniques in many 1 

more areas, including 

automatic flight control and guidance systems. 

The technology was attractive because it 

promised potentially significant savings in fuel 

consumption and cost of equipment ownership 

for the airlines. These savings were possible 

because digital equipment was lighter and 

generally required fewer components than analog 

systems. It was also proving to be highly reliable, 

easy to troubleshoot, and could often 

expected to incorporate - 

flight profiles.’ This capability 

became increasingly important 

to the airlines as jet fuel prices 

soared throughout the 1970s.’ 

Computer driven CRTs, 

like those used for the displays 

in the afi cockpit of NASA’s 

737 airplane, had not been 

incorporated into any 

commercial transport airplanes 

when the TCV program began, 

but they were not an entirely 

new concept. Electronic 

displays had been used 

extensively in military aircraft 

since 1960, and they were 

considered important components not only for 

the SST design, but for the new NASA Space 

Shuttle, as well. Electronic displays could help 

reduce a pilot’s workload by integrating separate 

instrument readings and pieces of information 

into a comprehensive picture of the flight 

situation. They were also considered vastly 

superior to conventional analog instruments for 

monitoring automatic guidance and navigation 
The forward flight deck 

of the NASA 737 near 

the time of arrival at the 

Langley Research Center 

in 1974. Note the 

profision ofgauges and 

dials and the yokes used 

to control the aircrdj. 

The co-pilot j position, 

however, has received an 

upgrade of electronic 

flight displrrys for resedrch 

into SST technologv. 

systems, which was an important consideration 

in the case of the space shuttle.' 

Prior to the 197Os, air transport operations 

were not considered sufficicntly demanding to 

require advanced equipment like electronic flight 

displays. The increasing complexity of transport 

aircraft, the advent of digital systems and the 

growing air traffic congestion around airports 

began to change that, however. 

problems of busy commercial airports, future 

airline operations were expected to include more 

complex approaches to airports and more closely 

spaced air traffic operations. Instead of the 10 

mile, straight final approaches that were typical 

with the Instrunient Landing System (ILS) that 

had hccn in use since the 1940s fiiture air traffic 

operations were cxpcctcd to rely on steep, curved 

approach paths with final legs as short as a mile. 

Airlincs were also beginning to look at 

improving low visibility landing capabilities of 

their aircraft, including the use of automatic 

In order to solve the capacity and noise 

landing systems. In order to accomplish all these 

maneuvers safely, airline pilots were going to 

need a much more accurate picture of the 

airplane's position at all times. They also had to 

be able to control the airplane's progress 

precisely and accurately monitor :iny automatic 

systems so they could take over if necessary.' 

This kind of precise knowledge about the 

aircraft situation would have been difficult, if 

not impossible, to gather from the 

instrumentation in most airline cockpits at the 

time.' The average transport aircraft in the mid1970s had more than 100 cockpit itistriinients 

and controls," and the primary flight instruments 

were already crowded with indicators, crossbars, 

and symbols. Airline pilots were having to 

iii on i to r a ti d tiin ti age nio re co m pl ex aircraft 

systems and operations, ;ind there was a growing 

consensus among rese;irch and industry 

engineers that conventionnl instrumentation was 

simply no longer adequate for thc job. What was 

needed were displays that could process the raw 

26 
.C 

aircraft system and flight data into an integrated, 

easily understood picture of the aircraft 

situation, position and progress, not only in 

horizontal and vertical dimensions, but with 

regard to speed and time, as well.? This was one 

of the strengths of CRT displays, and it was the 

reason the NASA engineers at Langley wanted to 

include electronic display research in the TCV 

program. 

Electronic Flight Display Research 

The overall goal of the TCV experiments 

with electronic flight displays was to examine 

how well the displays worked and how they 

could be used in a transport cockpit. In 

addition to validating the benefits of the basic 

equipment, several different display concepts 

were tried and evaluated to see if they would 

improve pilots' situation awareness and their 

ability to compensate and correct for flight 

path errors. 

Much of the development work was actually 

conducted in the Transport Systems Research 

Vehicle (TSRV) simulator at the Langley 

Research Center, but promising display concepts 

were then incorporated into the 737 airplane's 

aft flight deck (AFD) for operational testing. 

There were a number of research flights 

dedicated specifically to evaluation of display 

concepts, but because the electronic flight 

displays were an integral part of the AFD, 

researchers were able to gather information on 

the displays in the course of conducting other 

research, as well.# During two years of flight 

demonstrations of the U.S. microwave landing 

system between 1976- 1978, for example, the 

TCV program engineers gained valuable 

information on the impact of electronic displays 

on pilots' ability to fly complex, curved 

approaches to airports.') 

The initial displays in the 737 aft flight deck 

were 5" x 7" monochrome CRTs. Each pilot 

position had two displays: an electronic attitude 

Original configuration of 

the ajflight deck of the 

NASA 737 with 

monochrome flight 

dirpkzys. Note the 'Brolly 

Handle "$ight controls. 
simulator at Langley. 

c 

x=. 

director indicator (EADI), and an electronic 

horizontal situation indicator (EHSI). The EADI 

contained the same basic information available on a 

conventional attitude indicator instrument; that is, 

pitch attitude, roll or bank angle, and raw vertical 

and horizontal (localizer and glideslope) tracking 

information for an ILS approach. Because of the 

flexibility offered by the electronic display format, 

however, the EXDI also offered some additional 

information and options. In an effort to provide 

the pilot with an improved awareness of the 

airplane’s situation, the screen also displayed the 

radar altitude of the airplane, symbols that showed 

if its airspeed was slower or faster than a selected 

target speed and if the plane was accelerating or 

decelerating, and an indication of the airplane’s 

actual flight path. 

On an electromechanical indicator, the 

airplane symbol was oriented around a “horizon” 

line that was drawn across the center of the 

instrument. If the airplane was level, the symbol 

would be directly on top of the horizon line. 

With the additional information being evaluated 

on the electronic display, however, researchers 

were concerned about whether they would be 

able to see individual elements clearly. In order 

to unclutter the middle of the display screen, the 

airplane symbol was biased up five degrees, so 

the symbol appeared five degrees above the 

horizon line when the airplane was actually level. 

The EADI display also came with three 

pilot-selectable options. A perspective runway 

and an indication of the airplane’s track angle to 

the runway could be included on the display. A 

second option was the addition of flight director 

symbols, which would show the pilot what pitch 

and bank angles to follow to stay on a 

predetermined flight path. The pilot could also 

select to superimpose all the display symbology 

on a real-time image received from a Lear Siegler 

Forward Looking, Low Light Level Television 

camera mounted in the nose of the 737. With 

this option, the pilot in the aft flight deck could 

actually “see” the airport and runway during an 

28 Airborne Trtrilbhzer 
i 

”A 

approach. The TV camera also served as a 

method of verifjing the accuracy of the runway 

symbology used in the display. 

reference information provided by an 

electromechanical horizontal situation indicator 

(HSI), but in a much more integrated, pictorial 

format. The EHSI was a map display that 

showed a diagram of the airplane’s pre-planned 

flight path annotated with navigational 

waypoints, geographic reference points such as 

airports and navigational radio beacons, and the 

location of selected terrain and obstacle hazards 

along the route. The display also showed the 

airplane’s current horizontal position on the 

flight path, represented by a triangle on the map, 

and dashed lines that indicated what the 

airplane’s location would be in 30, 60, and 90 

seconds if no further flight control inputs were 

made. The actual magnetic compass heading and 

track of the airplane were indicated at the top of 

the display. The map could be oriented in either 

The EHSI displayed the same navigational 

a conventional “north-up mode,” or a “track-up 

mode” which showed the direction the airplane 

was flying at the top of the screen, regardless of 

its actual compass heading. The display could 

also be set for numerous scales, ranging from one 

to 32 nautical miledper inch. Additional options 

included the ability to display altitude or speed 

targets associated with waypoints, and even time 

reference information for experimenting with 

“4-D” navigation. 

display was to provide pilots with integrated, 

intuitively understandable information that 

would give them a more accurate picture of the 

airplane’s exact situation at all times. Armed 

with this information, pilots were expected to be 

able to monitor and control the airplane’s 

progress much more effectively and precisely in 

both manual and automatic flight modes. 

accomplished through a flight mode called 

“Control Wheel Steering (CWS). Instead of a 

As with the EADI, the objective of the EHSI 

Manual flight from the aft flight deck was 

The aftftigbt deck of the 

NASA 737 in 1987. 

An upgraa’t in 1386 

replacedfour original 

5 x 7 monochrome 

displays with eight 

8 x 8 color monitors. 
The aft flight deck of 

the NASA 737 after a 

1988 mod$cation. The 

pilot position j “Brol(y 

Handle ”flight controls 

have been rephced with a 

McFadden sidestick 

controller while the 

co-pilot position has not 

been modified. 

J 

direct linkage from the control yokes (or “brolly 

handles”) to the airplane’s flight controls, CWS 

took the pilot’s control inputs and processed 

them through the airplane’s digital flight 

computer, which, in turn, operated the flight 

controls. This allowcd the pilot to command 

changes in the airplane’s pitch or bank angle 

while delegating the actual stabilization 

functions to the computer. One of the concerns 

often voiced by pilots and human eiigineering 

specialists about automated cockpit functions 

was that they would eliminate the pilot from the 

control loop entirely, leading to an undesirably 

low level of activity for the pilot and even a 

decay in his flying skills.”’ The idea behind CWS 

was to reduce the pilot’s workload without 

ail to mating the tl igh t control fii nctio 11 en t i re1 y, 

so that the pilot would remain “in the loop.” 

Even in 1974, control wheel steering was not 

an entirely new concept. The McDonnell Douglas 

Aircraft Company’s DC- 10 wide-body airliner had 

a CWS mode that allowed the pilot to control the 

autopilot through inputs to the control yoke. The 

TCV set-up, however, had a couple of slightly 

different twists. The digital flight control computer 

that drove the autopilot in NASA’s 737 allowed the 

research engineers to experiment with different 

control laws and algorithms. So in addition to a 

more standard “attitude” control wheel steering 

mode, the 7.17 could be operated through a second 

control law concept, called “velocity vector conrrol 

wheel steering.” 

Velocity vector control meant that the pilot’s 

inputs commanded changes in the airplane’s 

tlight path instead of its attitude and bank angle. 

The rationale was that the end result a pilot was 

trying to achieve through attitude and bank 

angle changes was, in fiict, control of the 

airplane’s tlight pith. With velocity vector CWS, 

the pilot’s control inputs told the computer what 

tlight path he wanted the airplane to follow, ;ind 

the computer would make whatcvcr attitude and 

bank changes were necessary to achieve that 

flight path. With a combination of the CRT 
diphys. 

I 

I 

displays and velocity vector CWS, the NASA 

researchers thought it might be possible for 

pilots to manually fly complex approach 

maneuvers with a high degree of accuracy and 

success, even in low visibility conditions." 

problems with the velocity vector CWS at first 

because of the way the control law was 

implemented and the EADI displays were 

configured. The displays initially showed the 

actual flight path of the airplane. When a pilot 

commanded a change in the flight path, there 

would be a slight delay as the computer and the 

airplane responded to the command. During 

that lag time, however, the flight path on the 

display would not have moved. So the pilot had 

to guess at how much of a control input would 

result in the correct amount of flight path 

change, and the frequent result was a series of 

oscillations as the pilot hunted for the correct 

flight path angle. This made precision control 

very difficult, so the displays were changed. 

The NASA research pilots encountered some 

Initially, the displays were modified to show 

both the commanded flight path angle and the 

actual flight path angle. Eventually, the actual 

flight path angle symbology was removed 

altogether, because when the commanded flight 

path symbols reached the position the pilot 

wanted, he could simply neutralize the controls 

and the computer would hold that path. 

The initial EADI displays were also oriented 

around the nose of the airplane, regardless of 

which CWS mode the pilot was using. In cruise 

flight or in a no-wind situation, this was not a 

problem, but on approaches with a crosswind, 

the nose of the airplane would be pointed to one 

side to compensate for the wind. So although the 

ground track of the airplane might be straight 

toward the runway, the display would show the 

runway off to one side. Pilots found this 

somewhat disorienting, so the displays were 

modified. In the attitude CWS mode, the 

displays were still oriented around the attitude 

indicator symbol and the nose of the airplane, 
The Electronic Attitudc 

Director Indiciitor 

(EADI) on thr NASA 

7-37 rewirch dirrrrlj. 

Top-Attitiide Centered 

EA DI firrniit orientrltioit 

iri ri crossioiiid iipproiidi. 

Ijottow- Fliglitpiztli 

irritrrcd EADI f ormirt ' 

nricirtcrtiori. 

but in velocity vector CWS, the displays were 

oriented around the flight path of the airplane." 

One of the more significant display concepts 

the Langley researchers tested in the TSRV 

simulator and on the 737 was the addition of the 

perspective runway, extended center line and 

track angle to the 

EADI. In essence, 

this gave the pilot a 

visual, 3-D picture of 

the approach on a 

single display, instead 

of just the raw 

localizer and 

glideslope data. 

Research experiments 

tested pilots' 

performance using 

the velocity vector 

CWS, with and 

without the added 

symbology on both 

straight-in 

approaches and 130 

degree curved path 

approaches with final 

legs as short as one 

mile. The results 

showed that with 

velocity vector CWS 

and the pictorial 

horizontal situation 

information provided 

by the runway and track symbols, pilots were 

able to manually fly the airplane on both types of 

approaches with the same precision achieved by 

pilots following conventional flight director 

commands for a Category I1 low visibility 

landing. ' ' 

The pilots' mental workload was lower and 

their performance was significantly better with 

the added pictorial information than with the 

basic EADI display. Research pilots conimented 

that the integrated format gave them a better 

understanding of the airplane's position and 

trajectory to the runway, which allowed them to 

more quickly recognize and recover from large 

course deviations with confidence." 

Unlike many research projects conducted by 

NASA, the electronic flight display work was not 

a formal research experiment with formal 

beginning and ending dates. The research began 

when the airplane arrived, and experiments on 

better display formats continued throughout the 

aircraft's 20 year history at the Langley Research 

Center. By 1978, however, the researchers had 

proven the viability of the basic concept and had 

demonstrated some significant potential benefits 

that integrated electronic flight displays, control 

wheel steering, and velocity vector control could 

offer." Consequently, researchers at the Langley 

Research Center were optimistic that some of the 

technology would be integrated into the next 

generation of commercial transport airplanes."' 

Of course, the TCV program was not the 

only effort to develop new technology for 

transport aircraft. Even before 1978, the 

commercial aircraft industry had begun to 

incorporate some advanced equipment into 

transport designs. The Lockheed-California 

Company, for example, certified an operational 

flight management system (FMS) for some of its 

L-1011 wide-body airliners in 1977. The system 

offered operators approximately 3 percent fuel 

savings by providing automated 3-D navigation 

and power management for fuel efficient flight 

profiles. That kind of improvement might not 

seem all that significant, but for a fleet with 10 

L-1011-1 aircraft a 3 percent savings translated 

to 1,750,000 gallons of fuel a year.' 

Airlines even incorporated an 8" square 

monochrome map display with thc flight 

management system. Unfortunately, the display 

proved unreliable, the company that manufactured 

it was unable to support it, and the displays were 

eventually removed from the L-1011s. Flight 

management systems, on the other hand, were 

offered on all L- 10 1 1-500 series airplanes." 

couple of distinct advantages over electronic 

flight displays when it came to gaining 

acceptance among ai r fra ni e manu fact ii rers, 

however. First, they were seen as having a lower 

technical risk than the CRT technology. Flight 

management computers were also perceived as 

An order of L- 1 0 1 1 -200s sold to Saudi Arabian 

Flight management computers (FMC) had a 

32 Airborne Trtrilbhzer 
having a more compelling benefit, since they 

offered operators concrete fuel savings in an 

era of rising fuel prices. Since the financial 

advantages of electronic flight displays were 

not as concrete or obvious, the work the 

TSRV did in developing CRT display formats 

and demonstrating their benefits in a 

transport aircraft environment played an 

important role in gaining acceptance for the 

“glass cockpit” concept. 

The Transfer of CRT Technology 

As the NASA researchers working with the 

TCV program developed new display concepts 

and discovered some of the benefits CRT 

displays offered, they disseminated that 

information in several ways. They wrote and 

presented technical papers and documents, and 

Langley even held a small symposium in 1975 to 

update industry and airline representatives on 

the progress the TCV program was making.” 

The most powerful method of technology 

transfer employed by the TCV program, 

however, was its cooperative working 

relationship with the team of engineers and 

technicians from the Boeing Commercial 

Airplane Company. The senior managers at 

Boeing who selected the engineers to work with 

the TCV program at Langley knew that the 

technology in NASA’s 737 was going to direct 

the next generation of equipment developed for 

transport airplanes. So they intentionally sent 

some of their brightest young engineers to work 

at Langley, where they could gain experience and 

knowledge about the systems, in the hope of 

incorporating some of that technology into the 

design of the company’s next airplane.’” 

In the mid- 1970s, Boeing began designing 

that new airplane, which would actually evolve 

into two aircraft: the wide-body 767 and the 

smaller 757. Several of the engineers who had 

worked on the TCV program at Langley were 

brought back and put in charge of groups designing different aspects of the 767 airplane. 

Delmar Fadden, for example, had been the head 

of the Boeing group at Langley from mid- 1975 

until January 1977. When he returned to Seattle 

in 1977, he was put in charge of the flight deck 

technology staff for the 767, which was responsible for the human performance aspects of the 

new airplane’s flight deck equipment. In other 

words, Fadden and his group looked at what 

information the pilots needed to have and how it 

should be presented to 

them. Since 

much of the 

TCV display 

work had been 

concerned with 

that same issue, his experience at Langley 

was extremely 

valuable. 

to gaining experience with 

new 

In 

technologies 

addition 

and 

I 

a first-hand understanding 

of what they could do for pilots, the Boeing employees who worked with the TCV program 

found their experience at Langley gave more 

credibility to the work they did at Boeing after 

they returned. In fact, John Warner, the head of 

the Boeing group at Langley for the first year of 

the program and now vice president of Boeing 

Computer Services, termed the joint Boeingl 

NASA work on the TCV program “the best example of good technolog transfer since the days 

of NACA.”” Yet for all that, the Boeing 767 and 

757 came very close to being produced with conventional electromechanical flight instruments in 

the cockpit. 

By 1978, the dynamics of airline management 

and transport aircraft sales was very different from 

what it had been when World War I ace Eddie 

Rickenbacker ran Eastern Airlines or even when 

Juan Trippe and Pan American Airlines ordered 

the first Boeing 747 jumbo jet in 1966. In the 

early days of air travel, the presidents of the 

airlines were often pilots. That began to change 

in the years following World War 11, but the 

airlines still had large engineering departments 

which put a high value on technological 

performance and were very influential in the 

Close-up of co-pilot? 

position on the aftflight 

deck of the NASA 737 

research aircraft showing 

“Brolly Handle ”flight 

controls and color CRT 

displays. 
Close-up of the nftfl;ght 

deck Automntir Gaidnnre 

nnd Control System 

(AGCS) displq on the 

Roeing 737 in 1975. 

The AGCS nllowedpilots 

to $elect diffirent types of 

flight guidnnce iind either 

nutornntir or rnnnuiil 

,flight modrs. 

34 

airlines' aircraft purchase decisions. In 1978, 

however, the airline industry was deregulated. 

Suddenly, the air transport industry was a highly 

competitive business. In a very short period of 

time, cost became practically the sole driving 

factor behind the airlines' purchase decisions. 

New technology now had to earn its way onto 

airplanes more than it ever had to before." 

concrete fuel savings for airline operators at a 

time when fuel conservation was becoming a 

high priority. But there was no such immediate 

problem driving the use of electronic flight 

displays. CRT displays offered advantages like 

improved situation awareness and more efficient 

air traffic control system operations, which were 

much harder qualities to quantify in terms of 

cost savings. In 

addition, the 

acquisition and 

maintenance costs 

of CRT displays 

were still uncertain, 

and any new 

equipment raised 

the possibility of 

having to train 

pilots to use it, 

which would be an additional cost to 

the airlines." 

NASA's 737, for example, had only small, 

monochrome displays. Color displays were in the 

process of being developed by several companies, 

but most had limited capability and were 

difficult to see in bright sunlight. Yet there was 

concern that the black and white displays would 

not be able to differentiate the numerous pieces 

and types of information the screens would have 

to display clearly enough." 

Initially, Boeing had planned to put 

electronic flight displays in the 767. But as 

development progressed, a lack of strong 

customer demand and the lingering uncertainties 

about the cqiiipment cost led the company to 

opt for electromechanical displays, instead. The 

engineers at Boeing and Langley who had 

worked on the TCV program were extremely 

The flight management computers promised 

r 

CRT technology also was not yet perfected. 

Airborne TriiilbLizer 

disappointed. They knew what electronic 

displays could do and how they could benefit 

pilots, but the inherent capability of the 

technology was simply not sufficient to win it a 

place in a commercial airline design." 

Then in September 1978, very late in the 

development cycle of the 767, Boeing reversed 

its decision and announced that the 767 and 757 

would both use electronic flight displays. The 

simple reason for the change in position was that 

Boeing had discovered a customer demand for 

the technology.'" There were several events and 

factors that helped to create that demand, 

however. 

ownership study and analysis comparing 

conventional electromechanical instruments 

In early 1978, Boeing had begun a cost of 

against both 

monochrome and 

color CRT displays. 

Cost comparisons 

were by no means 

precise, because the I result depended 

heavily on what 

used in the future. However, a number of 

vendors supplied Boeing with figures and, in 

mid-1978, Boeing presented the study 

conclusions to its airline customers. The results 

showed that monochrome CRT displays might 

actually be more cost-effective than 

electromechanical instruments, although the cost 

of ownership for color displays would probably 

still be slightly higher.' 

At the same time, NASA's 737 airplane 

was just finishing a demonstration program of 

the U. S. microwave landing system. During the 

demonstrations, a number of airline and 

industry representatives had been given the 

opportunity to fly on the airplane and observe 

the displays in action during curved path, 

automatic and manual approaches in a real-life 

air traffic control situation. Between the MLS 

demonstrations and the other display research 

flights, the NASA researchers gave a significant 
number of airline pilots and operators the 

opportunity to become familiar with the 

technology and the potential benefits it might 

have for airline operations. “(The NASA 

researchers) were very open, answered any 

questions and provided as much information as 

they had,” Boeing engineer Delmar Fadden said. 

“I think that was as important as anything we 

might have done, and maybe more important in 

the broad scheme of things. Without that 

happening, I’m not sure that the airline people 

would have decided to (buy the displays).”’R 

The more favorable economics and the 

decision-makers’ ability to actually see the 

technology in use and gain an understanding of 

some of its future potential, tipped the scales. 

Boeing’s customers told the airframe 

manufacturer that they 

wanted CRT displays. 

Since they still had 

concerns about symbol 

differentiation on 

monochrome screens, 

however, the airlines 

told Boeing managers 

they wanted color 

displays, even if the 

cost of ownership was a 

little higher. The 

Boeing mangers and 

engineers agreed, but since they were still 

concerned about the state of color CRT 

technology, a two-pronged development effort 

was initiated, with color displays as the primary 

goal, and monochrome displays as a back-up.’” 

worried. While the decision about CRT displays 

was being debated in Seattle, Rockwell 

International’s Collins Air Transport Division 

had been quietly working on a type of display 

the industry had concluded could not be built at 

the time: a shadow mask, multi-color CRT 

display, bright enough to be seen in any lighting 

condition. While this technology was being used 

for color television sets, none of the avionics 

companies had been able to develop a 

“ruggedized” version that could withstand the 

vibrations and forces to which aircraft 

The Boeing managers need not have 

equipment was constantly subjected. Collins, 

however, contacted the Toshiba and Mitsubishi 

television manufacturers in Japan, who agreed to 

develop and build a custom, ruggedized version 

of their color CRT displays specifically for 

airplane use. In December 1978, Collins 

unveiled their displays, and the discussion of 

what kind of CRTs would go into the 767/757 

and who would build them was over.’” 

Color electronic flight displays consequently 

became standard equipment on Boeing’s newest 

airplanes. Both the 767 and the smaller 757 had 

very similar flight decks, in order to reduce pilot 

training time and costs for airlines. Both 

airplanes were covered by a single FAA type 

rating, which meant that pilots trained in the 

757 would also be certified to fly the 767, and 

vice versa. 

Not all of the 

capabilities of the 

displays in NASA’s 737 

were incorporated, 

however. The CRTs in 

the 767 and 757 

consisted of two 

4.7“ x 4.2” color EADI 

monitors, or “Primary 

Flight Displays,” as 

they became known; 

two 4.7” x 5.7“ color 

EHSI, or “navigation” displays, (one each for the 

pilot and copilot positions); and two more 

5.7“ x 4.7” displays for engine instrumentation 

in the middle of the instrument panel. The flight 

critical information displayed on both displays 

was backed up by electromechanical instruments 

in the panel. 

to the one in NASA’s 737. The EADI, on the 

other hand, was essentially a replication of an 

electromechanical attitude indicator. It did have 

a few extra pieces of information displayed on it, 

such as the airplane’s ground speed, radar 

altitude and decision height altitude for 

instrument approaches, and indications of what 

flight modes (such as speed hold, autothrottle, 

autopilot, lateral navigation or vertical 

navigation) were activated. The velocity vector, 

The EHSI display was actually very similar 

Close-up of EADI 

CRTflight dicplay 

showing somewhat steep 

descent (40 degree flap) to 

run way. Run way 

centerline is extended to 

horizon, the ‘)ole” in the 

center is to give the pilot 

something to steer toward. 

The diamond symbol 

indicates where on the 

runway the airplane will 

touch down $no changes 

are made. 
Close-up of 'ajt flight deck 

C,XT electronic displdy 

showingjigbt path fir 

(ipproiich to runwdy and 

nircri.$ attitude. The 

tsimigLe yvi bo1 on the 

map disphy (bottom) 

showj the location oj"tbP 

~iirpliine. 7%e dotted line 

stm on tbeprimqfliRl,t 

disphy (top) indictitex tbe 

phnr is piissing n 

uqpint or dppromhjx. 

perspective runway and track information tested 

so successfully in the TCV program were not 

included, however. 

The reason the airlines chose a simple 

replication of the existing attitude indicator was 

to help make the step to electronic flight displays 

an evolutionary change, rather than a 

revolutionary one. Theorists and futurists often 

discuss the psychological resistance to change, 

especially revolutionary change, in 

organizations." In the case of airline operators 

and CRT displays, however, the resistance was 

due more to economic and safety concerns than 

psychological factors. If an airline wanted to put 

a revolutionary new technology in a flight deck, 

it might have to go through a more complex 

certification process with the FAA, and all its 

pilots would have to be retrained to use the new 

equipment. In addition, if the cockpits of 

different airplanes flown by the same airline 

were radically different, it would be difficult for 

pilots to transition back and forth between 

airplane models, and the chances of pilot error 

could increase. 

Against all of these potential negative 

consequences of making radical changes in the 

flight deck, there was not yet a sufficiently 

compelling need for a velocity vector flight 

control law or display. The pilot's task had not 

changed significantly, as it would have with an 

SST design, and pilots were operating airliners in 

a perfectly satisfactory manner. NASA and 

Boeing had developed a solution that lacked a 

big enough problem to require its use. 

Nonetheless, several senior Roeing managers 

remained confident that velocity vector controls 

and displays would eventually be incorporated 

into a commercial airplane design." 

so intuitively easy to understand that pilots 

required minimal transition training, which is 

why the airlines elected to use the new display 

format. The CRT map display still retained the 

capability of being configured as a conventional 

horizontal situation indicator, however. 

By introducing electronic displays that had 

the flexibility to be updated later, but could be 

configured initially with a simple replication of 

In the case of the EHSI, the map display was 

Airborne Trnilbhzer 

conventional airplane instruments, the airlines 

hoped to break down what could have been a 

revolutionary change into a series of smaller, 

evolutionary steps. '' But CRT displays were not 

an isolated advancement. They were part of a 

new approach to flight deck design that 

incorporated digital, automated equipment like 

flight management computers and engine 

indication and crew advisory systems (EICAS) 

and forced a re-evaluation the pilot's basic role in 

the cockpit. By themselves, the electronic flight 

displays would not have been that dramatic a 

leap. All of these changes together, however, 

caused a revolution in the design and operation 

of commercial airliners. 

The Cockpit Revolution 

The advent of computerization and 

automation in the cockpits of commercial 

airliners allowed the airlines to reap a wide 

variety of benefits. In addition to fuel-efficient 

flight profiles, more reliable equipment and 

greater flexibility for upgrades, airlines were able 

to certify even large, wide-body airplanes like the 
767 and the 747-400 for operation with only 

two pilots. The switch initially encountered 

fierce opposition from airline pilots’ unions, but 

it had great appeal to airline operators because of 

the cost savings involved. The crew reduction 

was approved by the FAA, however, after a 

presidential task force formed to study the 

subject3* concluded it posed no safety threat, 

primarily because the EICAS technology 

The Sperry Flight Systems CDU consisted of 

a complete alphanumeric keyboard with 15 

additional “mode” keys and a series of “select” 

keys on either side of a small CRT screen that 

displayed navigation and performance data, all 

on 5.75“ x 9” unit.’* As early as 1977, researchers 

acknowledged that the CDU was designed for 

“navigation, not for man-machine 

communication,”” but it was the best technology 

automated many of the 

functions previously 

delegated to the third crew 

member.” 

The new cockpit 

technology also caused some 

unanticipated problems, 

however, illustrating the fact 

that technical advances are 

not always a simple forward 

movement. Technology can 

sometimes cause new 

problems even as it solves 

old ones. 

Researchers in NASA, 

academia and industry all 

recognized that the new 

cockpit technology and 

available at the time. The 

unit was difficult to operate 

because every command or 

piece of information had to 

be typed into the computer 

with a specific sequence and 

coding that was difficult to 

~emember.~” When pilots 

tried to input new 

commands during phases of 

flight that were particularly 

demanding, such as during 

approaches or immediately 

following departure, they 

were finding themselves 

overloaded. Sometimes both 

pilots would get engrossed in 

trying to operate the 

automation could cause some problems, 

especially with regard to the role of the pilot and 

pilot-machine interfaces. For the first time, 

human factors became an integral part of design 

analysis, and researchers looked closely at 

optimum levels of pilot workload and ways to 

keep pilots involved in the computerized 

systems. Delmar Fadden’s flight deck technology 

group at Boeing, for example, was formed 

specifically to look at the human performance 

aspects of the 767’s new cockpit technology.’6 

automated systems would cause the pilots’ 

workload to become too low, and the pilots 

would be too far out of the control loop. After 

the 757 and 767 had been in operation for a few 

years, however, pilots began complaining that far 

from being too low, their work load was actually 

too high. The main culprit was the control and 

display unit (CDU), which was the pilot 

interface with the flight management system.’- 

The researchers’ main concern was that the 

computer, leaving nobody looking outside the 

windows for possible conflicting traffic. 

The problems caught the engineers who had 

researched the technology and designed the 

systems by surprise. NASA and Boeing engineers 

concluded they had “underestimated how 

aggressive pilot crews would be in trying to use 

the flight management equipment.” Gradually, 

airline training programs began to teach pilots 

not to use the flight management computer at 

altitudes under 10,000 feet. but to hand-fly the 

airplane instead. Second and third generation 

CDUs are also somewhat simplified, but the 

problem still exists to some extent today.4’ 

The experience with the flight management 

technology taught the researchers at Langley an 

important lesson about technology application. 

Computer technology was a new, emerging 

technology when the TCV program started its 

experiments with flight management systems 

and electronic flight displays. Nobody could 

Close-up of the Spery 

Flight Systems Control 

and Display Unit 

(CDU). These were the 

least user fiiendly 

elements in the new 

Computerized ‘glass 

cockpit, ”ana’ caused a 

number of unanticipated 

problems when the 

equipment was put into 

commercial use. 
have guessed how quickly the technology and 

its use would spread and progress. Now, 

however, researchers caution that “if you put 

technology in (a cockpit), you’d better know 

all the ramifications, because pilots will want 

to use it.”” 

new technology was implemented and to better 

anticipate the ways pilots would try to use it, 

NASA developed the Aviation Safety/ 

Automation Program in 1989. The program, 

which was a joint effort between the Langley 

Research Center and the NASA Ames Research 

Center in California, set out to take a second 

look at the impact of the automation that is 

coming into cockpits. Then, using advanced 

concepts flight simulators (ACFS) at Ames and 

Langley, researchers planned to explore concepts 

that would lead to more “human centered 

automation,” in which the automation would be 

designed to assist pilots in their jobs instead of 

trying to do their jobs for them. 

In 1992, NASA also joined with the FAA 

and the Air Transport Association’s Human 

Factors Task Force to develop a National Plan 

for Aviation Human Factors. The task force 

objectives included correcting some of the 

current deficiencies in automated cockpits, 

furthering human-centered automation, and 

encouraging development of advanced displays 

and controls that are more “user-friendly.”“ 

Even with the unanticipated problems that 

arose with automated cockpits, however, pilots’ 

overall opinions about the technology were 

favorable, and the enthusiasm for electronic 

flight displays was very high. Pilots liked the 

improved situation awareness the displays 

provided, and according to the National 

Transportation Safety Board, as of 1993 there 

had not been a single accident involving an 

electronic map display-equipped airliner where 

the pilot became confused as to his location and 

flew into terrain. In two surveys of 757 pilots 

conducted by the Amcs Research Center in 1986 

and 1987,85-90 pcrccnt of the pilots said they 

considered the “glass cockpit” displays and 

instruments a “big step forward.”” Furthermore, 

all new transport aircraft designs since the 

In an effort to improve the manner in which 

Airborne Trailblazer 

Boeing 767 and some new models of existing 

airplanes, including the 300, 400 and 500 series 

of the Boeing 737, incorporated electronic 

flight displays. 

The fact that not all the elements of the 

electronic flight displays tested in NASA’s 737 

were used in commercial transport airplanes 

illustrates the complexity of the technology 

transfer process. Nevertheless, the aircraft and 

the TCV program played a very important role 

in allowing CRT displays to be incorporated 

into aircraft designs as early as they were. In a 

June 6 1979 letter to John Reeder, who was then 

the chief of the TCV program at Langley, the 

Boeing Commercial Airplane Company’s vice 

president of engineering, Mr. H. W. 

Withington, described the contributions the 

Langley research program had made to the 

development and acceptance of electronic 
flight displays. 

Withington noted that the instruments 

“were expected to contribute to both the safety 

and efficiency of flight through a better 

comprehension by the pilot of the airplane’s 

situation relative to its environment,” and he 

credited the TCV program with the 

development of several specific aspects of the 

displays, including the EHSI format and 

symbology. But the program’s most significant 

contribution, he concluded, was that it 

“provided the vehicle to bring electronic 

vertical and horizontal cockpit display 

instruments from the laboratory to industry 

acceptance” by demonstrating the technologies 

to the point “where both the aircraft 

manufacturer and the user had sufficient 

confidence to incorporate them into the 

new airplane^."^^ 

In other words, had the TCV program 

research been conducted in simulators and 

disseminated only through technical reports and 

conferences, the Boeing 767 and 757 might very 

well have been built with conventional flight 

instruments. Certainly, there were other factors 

involved. If the displays had proved costprohibitive to include, for example, the discussion 

would have gone no further. As it was, the 

technology still had to gain the confidence and 

acceptance of Boeing and the airline industry 

against concerns over any new cockpit technology 

and the lack of a clear, quantifiable cost advantage 

of using the displays. The TCV program’s close 

working relationship with rising young engineers 

at Boeing, and the fact that the program had an 

actual transport airplane with which to test and 

demonstrate the technology, allowed electronic 

flight displays to gain that acceptance. 

Chapter 4 

A Technology Eclipsed: 

Lefi- The NASA 737 

Advanced Transport 

Operating Systems 

(A TOPS) Program 

aircrafi knding at 

Wallops Island in 1392. 

Right- The NASA 737 

research aircrafi on the 

wallops runwuy in 1987 

with the Microwave 

Landing System 

equipment in the 

f. regrou nd. 

The Microwave Landing System U 

and the Dawn of GPS 

rior to World War 11, aircraft approaches 

and landings in poor weather conditions 

were often high-risk endeavors. Early civilian air 

navigation systems provided only basic lateral 

position information, and 1930s airline pilots 

flying in low visibility conditions had to take a 

heading off a radio navigation station and then 

use speed, time and distance calculations to 

figure out when they 

should see the 

runway at their 

destination. Safe 

descents were 

dependent on the 

accuracy of their 

calculations and all 

final approaches had 

to be visual, because 

there was no 

instrument guidance 

system that could 

direct a pilot on a 

safe, precise descent profile clear of terrain. 

The successful demonstration of a full 

Instrument Landing System (ILS) in 1937,’ 

therefore, marked a significant advancement for 

air transport operations. For the first time, pilots 

could tune in a radio signal emanating from an 

airport runway and receive precise lateral and 

vertical guidance on an approach and landing. 

The ILS broadcast a straight, narrow VHF/UHF 

signal beam that started at the runway and rose 

at a steady, three degree angle. By centering the 

vertical and horizontal needles on his ILS 

instrument, a pilot could fly down the ILS 

“beam” to the airport, descending on a gentle, 

three degree glide slope that was lined up 

perfectly with the runway centerline and clear of 

any terrain or obstacles. The system not only 

improved the safety of airline operations, but 

also increased the reliability of air carrier service, 

since it allowed 

airliners to operate in 

a wider range of 

weather conditions. 

U.S. airlines 

began using ILS 

approaches on a 

World War 11, and 

- regular basis after 

by 1949, the ILS had 

become the world 

standard for landing 

guidance systems. 

By the late 1960s, 

however, air traffic congestion and the need for 

more noise-sensitive approach paths to airports 

had begun to demand a more capable and 

flexible landing system. One problem with ILS 

was that the VHF/UHF frequencies in which it 

operated had a limited number of channels. As 

air transportation became more popular, 

planners began to see a time when certain areas 

of the country would have more airports 

requesting instrument landing systems than the 

ILS frequency range could accommodate. The 
The Microwave Landing 

System approach vectors. 

The expanded coverage of 

the MLS tracked signals 

within an area 120° 

wide and2OO high from 

the runway centerline. 

Elevation Beam 

1 O Above the Horizon 

to 20” (MAX) 

relatively low frequency range of the ILS was also 

susceptible to signal reflection, or “multipath,” 

errors. 

Another limitation of the ILS was that it 

allowed only one approach path to a runway. 

Airplanes would lock on to the ILS horizontal 

“localizer” and vertical “glide slope” up to 10 

miles away from the runway, and fly a straight 

course in for a landing. Two of the top priorities 

identified by the Department of Transportation/ 

NASA “CARD” study in 1971, however, were to 

increase the air traffic capacity of airports and to 

develop approaches that avoided noise-sensitive 

areas.’ The curved, segmented approach paths 

suggested by Jack Reeder and others in NASA 

and the FAA’ could accomplish both of those 

goals, but they would require a more flexible 

landing guidance system than the ILS. 

In 1968, Special Committee 1 17 of the 

Radio Technical Commission for Aeronautics 

(REA)’, representing both military and civil 

U.S. airspace users, was formed to develop the 

requirements and specifications for a new 

aircraft approach and landing system.’ Four years 

later, the International Civil Aviation 

Organization (ICAO), an agency of the United 

Nations that oversees international civil aviation 

procedures and standards, began the official 

selection process for a new precision approach 

and landing guidance system standard. Member 

states were invited to submit system proposals, 

and ICAO’s All Weather Operations Panel 

(AWOP) was given the responsibility of 

evaluating the proposals and making a 

recommendation to the organization as to which 

system should be adopted as the standard.” 

By this time, the U.S. Federal Aviation 

Administration, working with the RTCA special 

committee, had already evaluated several types of 

technologies and had decided that a microwave 

frequency-based, scanning beam format would 

make the best landing system. The higher 

frequency microwave band would alleviate the 

frequency allocation and some of the multipath 

signal problems, arid a scanning beam technique 

would provide broader signal coverage, allowing 

more flexible airplane approach paths. There 

were two ways of designing a scanning beam 

microwave system, however. One, called a 

“Doppler Scan” technique, used modulations in 

42 Airborne Trailbhzer 
frequency to tell a pilot where he was in relation 

to the runway. The other, called the “Time 

Reference Scanning Beam” (TRSB) technique, 

used time-referenced sweeps of a single 

frequency to pinpoint an airplane’s location. 

demonstration contracts for two separate 

industry teams to evaluate each of the two 

systems. ITT/Honeywell and Hazeltine/Sperry 

each developed a Doppler system, while Texas 

Instruments and Bendix Corporation each 

developed a TRSB system. The systems were 

evaluated by a 17-man steering committee of the 

Microwave Landing System (MLS) central 

assessment group, made up of representatives 

from the Federal Aviation Administration, the 

Department of Transportation, the National 

Aeronautics and Space Administration and the 

Department of Defense. In early 1975, the 

TRSB microwave landing system was chosen as 

the U.S. candidate for international 

standardization.’ 

and the Doppler designs were both actually very 

close, but the TRSB appeared to have slightly 

better performance at sites that were particularly 

susceptible to signal reflections, such as airports 

surrounded by high buildings or terrain. In the 

TRSB system, an airplane’s horizontal and 

vertical location was determined by two separate 

microwave beams with very precisely timed 

scanning patterns. The first beam swept back 

and forth across the runway centerline (plus or 

minus 60 degrees on each side) at a rate of 13.5 

times per second. The second swept up and 

down from the runway elevation to a position 20 

degrees above that at a rate of 40 times per 

second. The airplane’s horizontal and vertical 

position could be determined by measuring the 

time difference in between each signal 

transmission received by the aircraft. By 

integrating that data with distance information 

from a conventional distance measuring 

equipment (DME) transmitter on the airport, a 

receiver on board an airplane could accurately 

pinpoint the plane’s location in relation to the 

runway. A third beam, scanning up and down 

over a 7.5 degree arc from the runway elevation 

In 1973, the FAA awarded feasibility and 

The performance and the cost of the TRSB 

40 times a minute, could also be installed to 

provide flare guidance for automatic landings. 

The net result was a system that could provide 

precise manual or automatic landing guidance to 

an airplane anywhere in a wedge-shaped area 

that stretched 120 degrees wide and 20 degrees 

high from the airport runway.8 

The TRSB system was not the only one 

submitted to ICAO, however. Australia also 

proposed a TRSB microwave system, but the 

United Kingdom was strongly advocating a 

Doppler Scan MLS. The Federal Republic of 

Germany proposed a dual DME system, and 

France submitted a plan based on a Ground 

Controlled Approach (GCA) technique. The 

U.S. representatives to ICAO had known that 

there would be other proposals. But after a 

couple of meetings, the FAA realized that the 

British were going to put up a very tough fight 

against the U.S. choice. To win acceptance for 

the U.S. candidate system, the FAA MLS 

program managers decided they needed to “look 

at all the assets available to us and see if we could 

exploit those in ways we hadn’t exploited them 

before.”q One of the assets they found was 

NASA’s Boeing 737 Transport Systems Research 

Vehicle (TSRV). 

had not anticipated using the 737 for official 

demonstrations of the microwave landing 

system, they had hoped to test curved path and 

variable glide path angles with two 

demonstration MLS systems the FAA had 

installed at NASA’s Wallops Flight Facility,In 

across the Chesapeake Bay from the Langley 

Research Center. In fact, several people in 

Langley’s Flight Instrument Division (FID) had 

already begun to gather data from the microwave 

systems at Wallops Island before 1975. The 

researchers wanted to model the MLS signals in 

order to experiment with ways to process the 

information for the advanced aircraft displays 

and guidance systems they were developing. 

Langley did not have access to any actual 

airborne MLS receivers, so the data collection 

was conducted with a MLS receiver Langley 

engineers built out of off-the-shelf high 

frequency receivers and high speed recorders and 

Although the creators of the TCV program 
MAP ofuectors jlown 

jir reseiirih uiitb the 

Mirrouiiilio Imiding 

System jIi& tt,sts in 

1378. l~crnonstrates 

three difirent curved 

paths possibk instead of 

the striiigbt linc pnth 

used jhr IIS. 

installed in a DeHavilland DH6-C Twin Otter 

airplane. The makeshift receiver consisted of "a 

huge rack, three bays wide, full of equipment," 

but it allowed the Langley researchers to get the 

MLS signal data they wanted." 

research branch at Langley had also begun 

experimenting with MLS aircraft antennas as 

early as 1974, evaluating designs and placement 

locations on an airplane that would create the 

broadest coverage and the least signal 

interference.'' As a result, researchers at Langley 

already had some basic groundwork 

accomplished by the time the FAA asked 

Langley to support its efforts to sell the TRSB 

system to ICAO. This was fortunate, because the 

job the FAA wanted the 737 to perform was not 

an easy one. 

The FAA's navigation division had originally 

asked the NASA researchers to provide 10 to 25 

hours of MLS data collection flights on straight 

approach paths in the summer of 1975." When 

the FAA MLS division realized how tough a 

Several people in the antenna and microwave 

fight the ICAO selection process would be, 

however, its managers decided that what they 

really needed was not just data, but a way to 

actually demonstrate some of the more 

impressive capabilities of the TRSB system. In 

the spring of 1975, the FAA asked the TCV 

program office if the TSRV 737 could perform 

a demonstration of curved path approaches and 

automatic landings to the ICAO All Weather 

Operations Panel. There was initially some 

concern within the TCV program office that the 

workload involved in preparing for a 

demonstration that complex would cause too 

many other research projects to suffer, but in 

July 1975, NASA agreed to participate in the 

demonstration.' ' 

The task ahead of the Langley engineers was 

considerable. The demonstration was scheduled 

for May 1976, only 10 months away, and the 

737 was not yet equipped to process MLS 

information or perform curved path approaches. 

In addition, the airplane was designed to use 

inertial navigation system (INS) data for 

(I\\\ ,:; Coverage 

\ 

Typical $A < k \ 

& 

\ ,. .\ ' / .l Vectored \\ s 

Nautical Miles 

.A 

1, / 

/ 9. 

J. / 

/ I / 

44 Airborne Trdbhzer 
autolands, which used internal gyros to 

determine movement from a known starting 

point. The FAA, however, wanted the ICAO 

demonstration autolands to be done without the 

use of an INS.” 

There was not enough time to develop a new 

automatic control system that would operate off 

of MLS signals, so the engineers decided instead 

to convert the MLS information into a more 

conventional signal format the airplane’s 

computers could recognize. A separate Singer 

Kerflot 2000 digital computer was installed to 

reformat the data from the MLS receivers and 

convey the translated information to the 

airplane’s existing navigation and flight control 

computers. Curved approach paths that would 

line up precisely with the runway were designed 

into the navigation computer and the autoland 

system was adjusted to use MLS signals for its 

navigation and guidance cues, although it still 

needed acceleration information from a 

secondary source for smooth control of the 

airplane.’” 

The engineering and design challenges of 

creating all the various pieces of the system and 

integrating them together and with the other 

equipment in the airplane would have been 

formidable in any event. But this particular 

research endeavor had the added pressure of a 

very public and non-negotiable deadline. If the 

system was not ready to go when it came time 

for the demonstration, it would reflect badly not 

only on NASA, but on the FAA and the United 

States itself. As a result, many people involved in 

the project put in extremely long hours 

throughout the fall and winter of 1975-1 976.” 

The TCV team put the concepts, calculations 

and systems through three different levels of 

sophisticated simulations before they even put 

the equipment on the actual airplane. They 

then took the 737 up to the FAA’s National 

Aviation Facilities Experimental Center 

(NAFEC) in March 1976 for more than five 

weeks of flight testing to work out any 

remaining problems in the equipment before 

the demonstration.’* 

Wind tunnel model tests 

ofplacement of the 

antennae for Microwave 

Landing System research 

in 1974. 
Considering how quickly the system had 

been developed, the flight tests went well. They 

were not entirely without incident, however. 

Several days before the ICAO demonstration, for 

example, the flight crew was monitoring an 

automatic MLS-guided landing in the airplane. 

Normally, when the flight path reached the 

point where the glide slope guidance began, the 

airplane would pitch down slightly as it began its 

final descent. Yet on this occasion, only 600 feet 

or so off the ground, the nose pitched up and 

kept rising. The safety pilots in the front cockpit 

took over, forced the nose down again and 

landed the airplane. Upon investigation, the 

researchers finally discovered that the problem 

was an incorrect algebraic sign on one of the 

computer tapes. Since the system was all 

experimental, the computer tapes were full of 

“patches” where programming modifications had 

been made. Every time the flight computers 

“crashed” (which happened ofien when the 

airplane hit a sharp bump on a runway), each 

patch would have to be reloaded individually. To 

try to simplify the process, a new tape had been 

made that incorporated all the patches, but a 

single algebraic sign had been transposed in the 

process, causing the pitch-up problem. 

On another occasion, a disconnected 

computer lead caused the airplane to initiate a 

roll as it approached the runway on crosswind 

landings. There were problems with the MLS 

receiving equipment overheating and breaking 

down. The crew operated in horrendous wind 

and weather conditions throughout the month 

of March. But when the all weather operations 

panel of ICAO arrived for the demonstration, 

everything came together.”’ 

The TCV program’s demonstration at 

NAFEC consisted of repeated automatic flight 

demonstrations of two basic MLS approaches, 

followed by automatic landings. The first path 

was an “S-turn” approach, which incorporated a 

90 degree turn to the right followed by a 180 

degree turn to the left, rounding out onto a final 

approach kg 3 miles from the runway. The 

second path was a descending 130 degree turn to 

the runway with a straight, three mile long final 

approach. The demonstration lasted for 10 days, 

Airborne Tridbhzer 

during which time 11 flights were completed. 

Each flight carried approximately 10 observers 

who rotated positions so that everyone got to see 

an automatic landing from both the aft flight 

deck, where the electronic displays were located, 

and the forward cockpit. Although the 

demonstration was conducted in severe wind 

and turbulence conditions, the results were 

impressive. The mean overshoot error of the 

airplane when turning final was about 30 feet, 

decreasing to 10 feet one mile before the runway. 

The mean vertical error at one mile was less than 

five feet. The performance of the second “EL2” 

elevation transmitter for flare guidance 

compared favorably with that of a radar 

altimeter, which was what airlines were using at 

the time for automatic ILS landings.”’ 

numbers in the research reports, however, was 

the fact that the ICAO panel members had not 

just observed a static viewgraph presentation, or 

even a flight demonstration of standard, straightin approaches using the new kind of guidance 

system. They had seen for themselves, with the 

help of the 737’s vivid, visual electronic displays, 

a transport airplane perform maneuvers that no 

other transport airplane had ever been able to 

accomplish. The ICAO panel didn’t have to 

imagine what the U.S. microwave landing 

system could do for air transport operations. 

They had already experienced it.” 

to perform some additional experiments with the 

MLS at the New Jersey technical center during 

the summer of 1976, including manually flown, 

curved path approaches with even shorter final 

legs, but they thought their involvement in the 

MLS selection process was essentially finished. In 

fact, however, it was just beginning.” 

One of the methods the FAA had used to 

evaluate the four candidates for the U.S. 

microwave landing system was computer 

simulation. A computer could model adverse 

effects that were not currently present at any 

airport, but were anticipated in the future as 

traffic and real estate development expanded. 

The agency had hired the Lincoln Laboratory, 

from Lexington, Massachusetts, to do the 

Even more significant than the exact 

Researchers in the TCV program continued 
simulation work. So by the time the 

international evaluation of systems began, 

Lincoln was experienced in modelling MLS 

signals and diagnosing potential “multipath,” or 

signal reflection, problems, and its work had a 

lot of credibility with ICAO members. 

In July 1976, the Lincoln Laboratory 

presented a report to a technical working group 

of ICAO that indicated the British-supported 

Doppler Scan MLS might be more susceptible to 

multipath errors in some future situations than 

anyone had previously thought. The British 

modified the system’s antenna scan pattern and 

alleviated the problem, but a new evaluation by 

Lincoln Laboratory indicated that the 

modification might make the system more 

susceptible to other multipath problems at 

certain sites. In March 1977, the FAA asked 

Lincoln Laboratory to look more closely at one 

such potential location, in Brussels, Belgium. 

Using the official map of the Brussels airport, the 

lab ran a new simulation of standard and low 

aircraft approach paths and determined that 

there might, indeed, be a significant multipath 

problem with the Doppler MLS. The results 

were presented to a meeting of the all weather 

operations panel of ICAO in Montreal, Canada, 

eight days before its crucial vote on which 

landing system to recommend to ICAO for 

adoption as the international standard. The 

decision of the 1 0-person panel was close, but 

the United States-backed TRSB microwave 

landing system was approved by a 6-4 vote. 

contingent promoting the Doppler system had 

been pushing for a competitive flight 

demonstration of the Doppler technique versus 

the TRSB system, arguing that regardless of 

what computer simulations showed, the real-life 

performance of the two systems was comparable. 

The British company that manufactured the 

Doppler system, Plessy Company, Ltd., also 

hired a lobbyist to promote the Doppler system 

to other elements of the U.S. government 

outside the FAA. The lobbyist conducted a 

campaign with Congressional representatives, 

the Department of Transportation, the White 

House, and the U.S. media to try to cast doubts 

Even before the AWOP vote, the British 

on the TRSB system, and put pressure on the 

U.S. ICAO representative to delay the AWOP 

vote. These actions did not sit well with the 

FAA, of course, and by the time the Montreal 

vote was held, the debate between the two 

contingents had become heated. 

immediately after the ICAO vote, however, 

when the British decided to test the Doppler 

system at the Brussels airport in order to prove 

the Lincoln Lab simulation wrong. Upon 

arriving at the airport, they discovered that one 

of the key buildings that had caused the 

multipath problem in the Lincoln Lab 

simulation did not, in fact, exist. It had been 

planned, so it was on the airport map, but it had 

never been built. When Lincoln Lab 

representatives travelled to Brussels and gathered 

their own on-site information about the airport 

configuration, and the lab reran the simulation, 

the results showed no significant difference in 

performance between the Doppler and TRSB 

systems. 

Accusing the FAA of intentionally 

misleading Congress and ICAO and subverting 

the scientific process, the British lobbyist 

intensified his campaign to pressure the U.S into 

comparative flight tests of the two systems. He 

also implied that the reason the FAA did not 

want to conduct the tests was that they knew the 

demonstrations would show no difference 

between the two systems. The controversy was 

approaching the dimensions of an international 

incident, and after the issue reached the level of 

hearings before the House Government 

Operations Committee’s government activities 

and transportation subcommittee in September 

1977, FAA Administrator Langhorne M. Bond 

agreed to a series of international 

demonstrations.” 

Once again, the aid of the TSRV 737 

airplane was enlisted.” The first demonstration 

was held October 31 - November 7, 1977 in 

Buenos Aires, Argentina, during a conference 

sponsored by the Organization of American 

States (OAS).” The demonstration flights were 

conducted at the Aeroparque Jorge Newbery, 

which had many approach path restrictions due 

The controversy took on new proportions 
to the fact that it was only 4 kilometers from the 

city center of Buenos Aires. The MLS 

equipment the FAA installed at the airport was 

more limited than that at the New Jersey 

technical facility, with an azimuth (lateral 

position) coverage of only 40 degrees on either 

side of the runway centerline. The FAA also did 

not install a second elevation transmitter for flare 

guidance, so the TSRV used a conventional 

radar altimeter for that portion of the autolands. 

The TCV program researchers designed two 

descending, curved path approaches to the 

Buenos Aires 

airport that 

followed the 

Rio de la 

Nata river, 

minimizing 

the noise 

impact on the 

heavily 

populated 

areas under 

the long, 

straight-in 

Arronnutical chnrt of 

crowded New York 

nirqare. 7%~ MLS zoordd 

help prevent conflicts 

between ni rpo rt flight 

areas. 

ILS approach. One of the paths had a 1.6 

nautical mile final approach leg, while the other 

had only a 1.1 mile final. During the 

demonstration, a total of 56 automatic 

approaches and landings were made, with 

accuracies similar to those achieved during the 

NAFEC flights in May 1976. As important as 

the statistical results, however, was the fact that 

the demonstration allowed ICAO representatives 

from the different OAS countries to observe the 

U.S. system in action on board NASA’s 737. 

Once again, the electronic flight displays gave 

the observers an impressive, visual illustration of 

the complex, automatic maneuvers that 

contributed greatly to the impact of the 

demonstration. ”’ 

Less than a month later, the NASA team 

took the airplane to the John F. Kennedy airport 

in New York City, where the U.S. TRSB system 

and the British Doppler MLS would both be 

tested. The New York metropolitan airspace wdS 

extremely congested, because there were three 

major airports UFK, LaGuardia, and Newark, 

New Jersey) all located in close proximity to one 

another. As a result, some of the ILS approach 

paths for one airport overlapped the air traffic 

control zones of another. This was an area where 

curved path approaches could make a 

tremendous difference in airport safety and 

capacity.” 

The demonstration flights lasted from 

December 5 - 13, and the weather conditions 

were harsh throughout the week. On five of the 

eight days, the approaches had to be flown with 

tailwinds exceeding 20 knots, and below freezing 

temperatures played havoc with the computer 

equipment on the airplane. On the first 

morning, for example, the electronic flight 

displays would not work. After an hour and a 

half of troubleshooting, the displays seemed to 

be fixed, but the same problem occurred again 

the next morning. The technicians in charge of 

the equipment finally figured out that the root of 

the trouble was simply that the display 

computers were getting too cold at night. They 

fixed the problem the first day by borrowing a 

hair dryer to warm up the affected computer 

component, and ended up taking that piece out 

of the airplane every night to store it in a heated 

trailer. In truth, the electronics technicians had 

one of the toughest jobs during the 

demonstrations, because in addition to flying on 

the airplane during the day, they had to fix any 

problems with the research equipment at night 

so the flights could be kept on schedule.’“ 

The path the TSRV 737 demonstrated at 

JFK was the most demanding yet. It followed the 

“Canarsie” VOR approach to runway 13L, 

which was normally used only in visual flight 

conditions because the final leg was less than half 

a mile long. 

The TSRV flew a total of 38 automatic 

approaches during the official demonstration at 

JFK and successfully completed 30 autolands. 

The safety pilots had to take over and land the 

airplane on eight approaches, but the 

performance of the airplane was considered “very 

successful,” considering the adverse weather 

conditions and the fact that the .44 mile final leg 

left the autoland system very little time to 

capture the final approach segment.”’ 

48 Airborne Trnilbhzt-r 
4 

c 

The British tested the Doppler system on the 

same runway two months later, but the British 

Aerospace (HS) 748 airplane had neither an 

autoland system nor the capability to fly curved 

approach paths. So although the British airplane 

performed numerous automatic straight-in 

approaches to a 50 foot decision height without 

any difficulty, the effect was not as dramatic as 

the 737’s autoland performance on the difficult 

Canarsie approach. 

The final MLS demonstration involving 

NASA’s 737 was for ICAO’s All Weather 

Operations Division, which had to approve or 

overrule the recommendation of the All Weather 

Operations Panel to adopt the TRSB design as 

the world standard for precision approach and 

landing guidance systems. The division meeting 

where the MLS vote would be taken was held in 

Montreal, Canada in April 1978, and both the 

British and the U.S. set up demonstrations of 

their respective systems. 

S-turn approach, designed to keep the airplane 

The 737 demonstrated a curved path and an 

clear of an Indian reservation just south of the 

airport. One of the paths also had a glide slope 

angle of over four degrees, as opposed to the 

three degree descent angle used for ILS 

approaches. As in New Jersey, Argentina and 

New York, the FAA had observers ride on board 

the 737 so they could see for themselves, with 

the help of the aft cockpit’s electronic flight 

displays, how well the airplane performed the 

curved, complex maneuvers and automatic 

landings. 3o 

On April 19, 1978, the all weather 

operations division of ICAO voted 39 to 24 

(with eight abstentions) in favor of the TRSB 

system. The decision remained politically 

charged up until the end, however, and the final 

vote was taken by secret ballot to protect the 

member countries from undue political pressure. 

difference between the British and U.S. systems. 

The TRSB design was a little more advanced, 

but the Doppler scan probably could have 

matched the TRSB performance with a little 

In truth, there was actually little technical 

The Microwave 

A Landing System flight 

demonstrations at 

Montreal, Canadt. 

The map depicts two 

curved-path MLS 

approaches demonstrated 

by the Langlq, 737 

during the 1378 IC40 

meeting. 
more development." By using the TSRV 737 for 

the flight demonstrations, however, the FAA 

gained a couple of distinct advantages in the 

competition. First, it gave the U.S. system what 

Frank Frisbie called the credibility of "the NASA 

logo." Second, the fact that the TSRV airplane 

could not only perform complex automatic 

approach and landing maneuvers, but could also 

display them visually on electronic flight 

instruments, gave observers a dramatic and vivid 

impression of the TRSB system's capabilities 

that the British could not match." 

After the April 1978 ICAO decision, the 

organization began developing Standards and 

Recommended Practices (SARPs) for MLS. The 

target date for switching over to MLS as a 

primary landing guidance system was changed 

from 1985 to 1995, but the future of the TRSB 

microwave landing system seemed assured. The 

technology was proven, the ICAO world 

organization had given its stamp of approval, 

and after the SARPS were written, all that 

remained was to produce and install the 

equipment. 

Yet 15 years later, only a handful of MLS 

installations had been completed, and it was 

uncertain whether the microwave landing system 

would ever be implemented, at least in the 

United States. In a telling example of how 

complex the technology application process can 

be, the MLS encountered so many delays and 

obstacles in the 10 years following the ICAO 

decision that it finally began to be overshadowed 

by an even newer technology: the Global 

Positioning System (GPS). 

contract for 178 of the 1,250 planned 

microwave landing systems to the Hazeltine 

Corporation in Commack, New York, in 

January 1984, The specifications for the 

equipment required only a Category I level of 

performance, however, because the FAA planned 

to put the first systems at small airports which 

had only Category I ILS equipment, or no 

instrument landing capability at all, to help ease 

the transition to MLS. I' Category I conditions 

were the least severe of the three low-visibility 

condition categories, requiring at least 200 foot 

The FAA awarded the first production 

Airborne Trailbhm 

cloud ceilings and a half mile of visibility. 

Actually, the guidance signal of the MLS 

equipment did not change from Category I to 

Category 111, but Category I1 and I11 

installations required a much higher level of 

redundancy in the equipment. 

The FAA planners hoped that by installing 

the first microwave landing systems at outlying 

airports, they would prove the flexibility of the 

system to provide coverage in areas unable to 

incorporate a standard ILS and begin to build a 

consensus of support for MLS among regional 

airlines and corporate aircraft operators. 

Interestingly enough, although the major airlines 

had initially pushed for the development of MLS 

in the late 1960s they were less enthusiastic as 

the time came to implement the system. Some of 

the problems with the ILS had been rectified, 

and the growing financial concerns of the airlines 

following deregulation made them reluctant to 

purchase new avionics for their entire fleets 

unless they could see some immediate benefit 

from the new equipment." 

The problem with the FAA's strategy was 

that installing Category I equipment at outlying 

airports offered no opportunities to show the 

airlines any of the more impressive advantages 

the MLS could offer them, such as more efficient 

approach procedures or better automatic landing 

capabilities." Nevertheless, had the 178 Category 

I systems been installed as planned, there might 

have been enough momentum to support the 

production and installation of the more capable 

Category II/III MLS equipment at airports used 

by the major airlines. But as it turned out, those 

first 178 systems were never delivered. 

Hazeltine Corporation had promised it 

would begin delivering the MLS systems 18 

months after its contract with the FAA was 

signed, The company ran into problems with 

software, however, and the delivery date was 

pushed back repeatedly. Four years later, 

Hazeltine had only delivered two systems, and 

the FAA finally cancelled the contract in 1989." 

By this time, numerous questions were being 

raised about the necessity of MLS, riot only by 

the airlines, but also by Congress and even the 

General Accounting Office.' More importantly, 
however, MLS technology was no longer the 

only alternative to ILS. 

its satellite navigation network available to the 

world. The system, which was developed 

originally by the Department of Defense for 

military purposes, was based on a constellation 

of geosynchronous satellites. By using satellitetransmitted radio signals to measure the distance 

from a receiver to several different satellites, the 

exact position of the receiver could be 

determined at all times. The Global Positioning 

System (GPS), as the U.S. satellite network was 

called, offered so much more capability and 

flexibility than any other navigation system that 

it was described as “the greatest opportunity to 

enhance aviation system capacity, efficiency and 

safety since the introduction of radios and radiobased navigation.”’* GPS was not dependent on 

any ground navigation aids, which meant that it 

could provide guidance in a much wider variety 

of locations than navigation systems based on 

radio transmissions from particular ground 

positions. GPS could also provide precise 

position and velocity information in three 

dimensions, at any instant in time, which other 

navigation systems could not do. 

however. To keep the defenses of the U.S. from 

being compromised, the Department of Defense 

intentionally degraded the accuracy of the 

satellite signals for civil use. As a result, the 

position accuracy was only within 300 feet, 

which was acceptable for navigation, but not 

precise enough for a landing system. These 

position errors could be corrected and the 

inherent accuracy of the satellite signals could be 

improved further through the use of 

“differential” techniques, although this approach 

did require ground installations. In a differential 

system, a stationary GPS receiver was placed at a 

surveyed location near the airport. The ground 

site would receive the satellite transmissions, 

compute how much correction was needed to 

match its surveyed location, and transmit that 

correction factor to approaching airplanes 

through a real-time data link. There were still 

questions about the capability of GPS to provide 

In 1983, the United States decided to make 

There were limitations on the system, 

enough accuracy for the most demanding 

instrument approaches, however.” 

Association (ATA) began to advocate the use of 

GPS, perhaps in combination with the current 

ILS system, as a possible alternative to MLS. 

Some simulation research had also started to 

evaluate the use of GPS for landing guidance 

systems, but there was still tremendous 

momentum within the FAA and the 

international community for the microwave 

landing system. The GPS movement got a 

tremendous boost, however, from a series of 

flight tests conducted in the fall of 1990 by 

NASA’s TCV/ATOPS program and the TSRV 

737 air~lane.~’ 

Ironically, the TSRV research was not even 

directed toward civil aviation use of GPS. 

Honeywell, Inc. had developed a GPS receiver 

integrated with an inertial reference unit (IRU) 

that it wanted to test to see if it was accurate 

enough to be used as a landing aid for returning 

space vehicles, such as the shuttle or an 

emergency crew rescue craft. Space vehicles 

generally land in good weather, on very long 

runways, however, so the accuracy requirements 

are not quite as stringent as those for commercial 

airline operations in extremely low visibility 

 condition^.^' 

Because the ATOPS 737 had extensive 

experimentation and data collection capabilities, 

Honeywell proposed testing its GPSlIRU system 

on the NASA airplane. One of the NASA 

managers suggested integrating the GPS/IRU 

equipment with the airplane’s existing autoland 

system, to gather some additional data on the 

performance of the equipment all the way 

through landing. The autoland portion of the 

experiment was almost dismissed, however, 

because from a research standpoint, there was 

little to be gained. The Langley engineers knew 

that the autoland system on the airplane worked, 

so performing autolands with Honeywell’s GPS/ 

IRU equipment appeared to be simply 

demonstrating a capability that was already 

obvious.” What the research engineers at 

Langley failed to appreciate was that while that 

capability was obvious to them, it was not yet 

Representatives of the airlines’ Air Transport 
obvious to the rest of the world. 

In October and the early part of November 

1990, the 737 performed a total of 25 hours of 

flight tests with the GPSIIRU system, using a 

differential GPS station at the Wallops Island 

flight test facility. Initial tests with just the GPS/ 

IRU guiding the autoland system showed an 

unacceptable vertical error, so a radar altimeter 

was integrated, as well. With that combination, 

the airplane performed a total of 36 successful 

Aerial virw cf WXlops 

Flight Fliciliv, udiere 

mniy ofthc ~i7 rmmrl/ 

j7igIits hmvr hiw 

'.#Mll4mll. 

GPS/IRU automatic landings. The airplane's 

performance did not meet the most stringent 

precision landing requirements, but it met 

Category I specifications (within 1 12.2 feet 

horizontal and 27.2 feet vertical accuracy) and 

came close to the 33.8-foot horizontal accuracy 

requirements for a Category I1 landing. 

To the researchers at Langley, the results 

were interesting, but not earth-shattering. In 

addition to the 36 successful autolands, there 

were others that had to be completed by the 

safety pilots, although that was typical of 

Category I landings. The accuracy of the GPS/ 

IRU/radar nltinietcr system also still fell 

substantially short of the microwave landing 

system." To the outside world, however, the 

specific error levels and the combination of 

equipment that the landings required were 

secondary. The ATOPS program had just 

demonstrated, in an actual transport airplane, 

that a GPS-guided autoland was possible. In a 

few test flights, the ATOPS researchers had 

changed the face of the GPS debate from a basic 

question of whether GPS could ever be used for 

landings to more specific questions about the 

degrees of accuracy and reliability that could be 

achieved." 

Honeywell tests in 1990 were not nearly good 

enough to support using GPS instead of MLS, 

but they helped build momentum for further 

research and development efforts. By 1993, GPS 

technology had already advanced so far that the 

ATOPS program began another series of test 

flights with equipment that, in theory, could 

achieve accuracies not only adequate for 

Category MI1 landings, but within 10-1 9 

centimeters. 

Inc. P 12 12-channel, carrier phase tracking 

receiver, with additional processing software 

developed by Ohio University. The Honeywell 

equipment tested in 1990 was a much earlier 

generation GPS receiver that used code tracking 

reception and only two channels. The carrier 

phase tracking receivers were more accurate, 

because instead of just locking on to a code 

associated with the GPS signal, a carrier phase 

receiver locked onto the actual GPS frequency 

wave itself. The Ohio University software was 

designed to improve the accuracy of the 

equipment even further by locking on to not 

only the frequency wave pattern, but the exact 

fr eq u e n cy cycle associated with the ai r p I a n e's 

position. '' 

Even if the Ashtech/Ohio University system 

performed flawlessly, some questions about GPS 

would remain, especially within the ICAO 

community. To be acceptable as a landing 

system, GPS would not only have to have high 

reli;ibility, it would have to bc able to alert pilots 

instantaneously if a satellite signal was flawcd. 

Thcr-c were also unccrtaintics aboiit how easy it 

would be to jam a GPS signal, and concerns 

anio ng the i n ter na t i o nal co m m 11 n it y ah 11 t 

relying on a satellite system owned and operated 

by the U.S. military."' 

The results achieved in the NASA/ 

The 1993 research effort used an Ashtech, 
In 1988, the Soviet Union also agreed to 

make its GLONASS satellite signals available for 

international civil use, which reduced some of 

the concerns about satellite availability and U.S. 

control of the system. ICAO designated an 

international satellite system, including GPS, 

GLONASS and any other country satellites that 

might be added to it in the future, the “Global 

Navigation Satellite System,” or GNSS.47 The 

political upheaval in what had been the Soviet 

Union following 199 1 left some uncertainty as 

to when or if the full complement of GLONASS 

satellites would be operational, however. 

ICAO finally decided to wait until 1995 

before determining whether or not to alter its 

plan to implement MLS. The original deadlines 

called for installation at all international airports 

by 1998 and transition to MLS as the primary 

navigation system by 2000. By 1995, the FAA 

and NASA were expected to have substantially 

more information on the potential and 

limitations of GPS, and ICAO members could 

determine whether they wanted to extend the 

deadline for MLS, shift the main navigation and 

landing system focus to GNSS, or look at some 

combination of the 

The landing system decision remained a 

highly charged issue, however, and there were 

split opinions both within ICAO and within the 

United States itself. The United Kingdom, for 

example, decided to proceed to MLS 

implementation without waiting for additional 

research into GPS. The poor visibility conditions 

in the U.K. made the ability to perform 

Category I11 landings a necessity, and ILS 

frequency congestion and interference problems 

were more severe in Europe than they were in 

the United States. The British reasoned that even 

if GPS technology could be developed far 

enough to provide the accuracy for Category 111 

operations and the questions regarding system 

integrity, reliability and availability could be 

resolved satisfactorily, development and 

implementation of the system would take too 

long.“’ 

The United States looked much more 

favorably upon a GPS or GNSS system, but 

there were still strongly divided views within the 

FAA, NASA and the aviation community about 

what the next landing guidance system should 

be. Most people agreed, however, that even if the 

MLS system was implemented, it would 

probably be in a much more limited capacity 

than originally envisioned.” 

The 25 year controversy over a new landing 

guidance system underscored just how much 

political, financial and other external factors can 

influence the acceptance and application of new 

technology. In the mid- 1970s, the microwave 

landing system clearly demonstrated its 

superiority over the existing instrument landing 

guidance equipment. Yet almost 20 years later, 

the old ILS system was still in use, and MLS was 

being overshadowed by an even more advanced 

technology. 

The landing system debate also showed once 

again the impact an airplane like the TSRV 737 

could have on the acceptance of new technology. 

With the use of the NASA 737, the backers of 

both the TRSB microwave landing system and 

the global positioning system were able to go 

beyond simply describing or simulating the 

capabilities of the technology. They could 

physically demonstrate its performance, in an 

actual air transport class airplane and in realistic 

flight situations. In the case of the MLS 

competition, this gave the U.S. candidate an 

edge the British entry could not match. In the 

case of GPS, it forced a re-evaluation of the 

system’s possible applications and generated 

momentum for further research and 

development efforts. The NASA 737 was 

continuing to prove that actual flight 

demonstrations could give new technology a 

level of credibility that no amount of laboratory 

testing or simulation could achieve. 

Chapter 5 

“The Best That We Can Do”: 

Taming the Microburst Windshear 

7-. 

:Q 

RV (Transport Systems Research 

icle) 732 made numerous contributions ---7 

nikeas during its 20 years at the 

Langley Research Center. But no effort involving 

the 737 was more successful, or had a greater 

impact, than the airborne windshear detection and 

avoidance program. 

Members of the Aeronautics Advisory 

Committee that oversees the research efforts of 

Left--Micro burst 

windshear research in 

Colorado in 1992. 

Thephoto was taken 

from a tail-mounted 

camera that photographed the aircraj? ? 

upper@selage and the 

horizon. 

Right-Forwardjlight 

deck of the NASA 737 

at the time the aircrafi 

entered a microburst 

windshear cell in 1992. 

dangerous if not planned and executed 

extremely well. 

Yet the NASA and industry researchers and 

technicians involved with the program rose to the 

challenge. In a remarkable seven-year effort, the 

windshear research team at Langley developed, 

demonstrated, and successfully transferred the 

technology to tame an aviation weather hazard that 

had caused 26 airline accidents and claimed more 

NASA called the -- -~ - 

windshear program L 

I “NASA at its best.”’ The 

windshear program was, 

I indeed, a classic research 

success story, and its 

achievements were even 

more extraordinary 

because of the significant 

organizational and 

technical challenges the 

program involved. The 

windshear research effort -- -I-. a- 4 

required an unusual number of cooperative 

relationships, not only among several different 

directorates at Langley, but between NASA and 

both the FAA and industry manufacturers. The 

research was subjected to a high degree of public 

pressure and scrutiny, with a deadline by which 

results had to be achieved. The technical obstacles 

were substantial, and many knowledgeable sources 

doubted they could be overcome at all. If technical 

solutions could be found, the flight testing would 

still be unusually challenging, and potentially 

than 500 lives since 

1964.’ 

The immediate 

catalyst for the NASA/ 

FAA winds hear 

program was a tragic 

event at the Dallas-Ft. 

Worth (DFW) airport 

on the afternoon of 

August 2, 1985. 

Thunderstorms were 

in the area of the 

Texas airport as Delta 

Flight 191, a L-1011 jumbo jet with 163 

passengers and crew on board, approached 

runway 17L for landing. There was a rain shaft 

and scattered lightning coming from a 

thunderstorm cell in the airliner’s final approach 

path, but the pilots decided the weather was 

passable and continued the approach. Fifteen to 

30 seconds after the L- 10 1 1 entered the weather, 

however, the rain and lightning intensified, and 

the airplane was buffeted by a violent series of up 

and down drafts. The headwind increased 
Le$- Windshear disphy 

used on the NASA 737 

research aircra$; disphys 

the location and intensiq 

of the wedther hnmrd. 

TJie aircrizfi j position is 

at the bottom of the cone; 

the &rk red areas 

indicate the greatest shear 

inti~~iq,. 7Ar red dot 

shows the F-Fixtor. 

Right- The 737 crew 

conducting windshear 

reseiirclr )om the ilfi 

jlight deck. Clockwise, 

from lower lefi, Rohnd 

Rowes, propmn manngrr; 

Lee Person, research pilot; 

Michnrl Lewis, depuq 

progriim maniiger; 

experimenter.s Eiiredio 

Hrmilcnte (ind ,!hid A. 

Hinton. 

rapidly to 26 knots, and then, just as suddenly, 

switched to a 46 knot tailwind, resulting in an 

abrupt loss of 72 knots of airspeed. The jet was 

only 800 feet above the ground when it 

encountered the severe weather, leaving the 

pilots little room to maneuver when the airplane 

began to lose airspeed and altitude at the same 

time. Thirty-eight seconds later, Delta Flight 

191 crashed into the terrain short of the runway, 

killing all but 26 of 

those on board.' 

The crash of 

Flight 191 jarred the 

nation. Just three 

years earlier, a Pan 

American World 

Airways Boeing 727 

departing the New 

Orleans International 

Airport had also 

encountered a severe 

windshear and 

crashed, killing 145 people on the airplane and 

eight more on the ground.' Two such accidents 

in three years, with the loss of almost 300 lives, 

was too much. With the wide publicity the 

Dallas crash received, "windshear" suddenly 

became a household term and the safety of air 

travel began to be questioned. Members of 

Congress were deluged with phone calls from 

constituents asking that something be done to 

prevent any more accidents.' 

organizations had been working on the problem 

of low level windshear for some time. As early as 

1949, researchers had begun to explore some of 

the potentially dangerous characteristics of 

thunderstorms, and in 1971 the FAA started a 

joint program with several research organizations 

to work on improving the forecasting and 

detection of windshear. The issue received 

renewed emphasis, however, when an Eastern 

Airlines Boeing 727 crashed on approach to 

runway 22L at rhc John F. Kennedy 

International Airport in New York on June 24, 

1975, killing 1 12 people." 

measurements and another aircraft in the area 

Actually, the FAA, NASA and other 

Information from meteorological 

Airbornr Trtrilblrrwr 

indicated that the airliner had encountered a 

strong downdraft of air and an abrupt switch in 

wind direction just prior to the crash. 

Researchers analyzing the accident looked more 

closely at the thunderstorm conditions the 

airliner had encountered and concluded that a 

particularly violent, deceptive, and deadly kind 

of windshear, which one researcher named a 

“microburst,” had caused the Eastern Airlines jet 

to crash.? 

Windshear, 

defined as a sudden 

change in wind 

velocity and/or 

direction, was not 

always dangerous. 

Aircraft often 

experience a shift or 

drop in winds in 

cruise flight, but at 

that point they have 

enough speed and 

Meter&& Dr. Fred H. 

Proctor on theground 

directing the NASA 737 

tor*//rrd microbursts wing 

n 7 ’erminnl DuppLer 

Wmthcr Kndnr. 

altitude to compensate for the loss of airflow 

over their wings. If an airplane encountered 

windshear during a takeoff or landing it was 

more serious, because the plane was close to the 

ground and had very little extra speed. A 

microburst windshear, however, was a unique 

phenomenon that posed a particularly deadly 

threat to airplanes. 

precipitation in a column of rising air 

evaporated, cooling the air very quickly. Since air 

became more dense as it cooled, the column of 

air would fall rapidly, spreading out in all 

directions with a great deal of force as it neared 

the ground. The phenomenon could occur in a 

variety of conditions, and not all microbursts 

had any rainfall associated with them. However, 

the strong, convective air currents in 

thunderstorms and towering cumulus cloud 

build-ups were particularly conducive to the 

formation of microbursts. 

were cspecially hazardous to aircraft because the 

first effect a pilot would notice was a 

performance-enhancing headwind (as the plane 

first encountered the outflow of the burst). If an 

A microburst occurred when the 

Low altitude encounters with microbursts 

airplane was on a landing approach, the pilot 

would typically respond by reducing the engine 

power to maintain the proper glide path angle 

and speed. As the plane progressed into the 

center of the microburst, however, the plane 

would be hit with severe downdrafts. Then, as it 

passed into the far side of the burst, the 

headwind would be replaced with a strong 

tailwind, causing a sudden loss of performance 

and airspeed. If the pilot had reduced power 

during the first stage of the microburst, this loss 

in performance would be intensified even 

further. Turbine engines take several seconds to 

spool up to provide additional power, and by the 

time a pilot realized the nature of the problem, it 

was often too late.” 

Another reason microbursts posed such a 

danger to pilots was that they were extremely 

difficult to detect. A microburst was usually less 

than 2.5 miles in diameter and lasted only a few 

minutes. To help give pilots better warning of 

potentially dangerous shear conditions, the FAA 

developed a Low Level Windshear Alert System 

(LLWAS) in 1976. LLWAS consisted of an array 

of wind velocity measuring instruments that 

were installed at various locations around an 

airport. The LLWAS compared the wind 

direction and velocity readings from the different 

sensors and, if a 15 knot or greater difference 

existed, transmitted an alert to the air traffic 

controllers, who could then notify pilots in the 

area. The system had a number of limitations, 

however. The instruments could not measure 

winds above the ground sensors and could not 

record vertical wind forces. An extremely 

localized microburst on a final approach path 

might not even be recorded by the sensors. Even 

alerts that were recorded took a couple of 

minutes to reach the controllers. 

Nevertheless, the LLWAS was an 

improvement ovcr the existing detection 

methods, which consisted of weather forecasts 

and pilot reports of weather conditions they had 

just encountered. By 1983, the FAA had 

installed LLWAS at 59 major airports and had 

plans to install the system at an additional 5 1 

locations.” The FAA also issued special Advisory 

Circulars in 1976 and 1979 that contained 

58 Airborne Trlrilhhzer 
information for pilots on windshear recognition 

and recovery techniques. In 1977, the FAA 

amended Part 12 1 of the Federal Aviation 

Regulations to require air carriers to adopt an 

approved system for obtaining forecasts and 

reports of adverse weather conditions, including 

low altitude windshear. The agency even issued 

an advanced notice of proposed rulemaking 

(NPRM) in 1979 that proposed making 

airborne windshear detection equipment 

mandatory for scheduled airlines, but the 

regulation was not enacted. lo 

In truth, the technology for airborne 

windshear detectors and the level of knowledge 

about the phenomenon itself were still very 

limited, although researchers were working on 

the problem. For example, engineers and 

meteorologists at the Langley Research Center 

began to explore windshear and microburst 

behavior in more detail in the early 1980s as part 

of a simulation technology program. In order to 

simulate the weather hazard accurately, the 

engineers had to first understand how it operated 

and how it affected aircraft performance. 

Understanding windshear behavior was a 

difficult challenge, however. The NASA 

researchers first had to study the basic 

meteorology and atmospheric physics associated 

with windshear and then, using extremely high 

fidelity fluid dynamics models run by super 

computers, try to model the phenomenon’s 

characteristics . I ’ 

Weather Studies (JAWS), the National Center 

for Atmospheric Research (NCAR) conducted 

windshear experiments in the Denver, Colorado, 

area during the summer of 1982. Researchers 

concluded that some of the microbursts recorded 

during the JAWS program created windshear too 

severe for landing or departing airliners to 

survive if they encountered it less than 300-500 

feet above the ground.” 

Yet even as the JAWS researchers were 

collecting microburst data in Denver, Pan 

American World Airways Flight 759 crashed in 

New Orleans, Louisiana. The airport’s LLWAS 

did trigger an alert, but not in time. The tower 

controller’s first broadcast warning of possible 

In another effort known as the Joint Airport 

windshear came two seconds after the Pan Am 

Boeing 727 hit the trees off the end of the 

runway.” The accident prompted Congress to 

pass Public Law 97-369, mandating the FAA to 

contract with the National Academy of Sciences 

(NAS) to “study the state of knowledge, 

alternative approaches and the consequences of 

windshear alert and severe weather condition 

standards relating to 

take off and landing 

clearances for 

commercial and 

general aviation 

air~raft.”’~ 

The NAS report 

was issued in May 

1983 and concluded 

that low altitude 

windshear presented 

an “infrequent but 

highly significant 

hazard to aircraft 

while landing or taking off.” Among the report’s 

recommendations was continued research into 

airborne windshear detection systems.I5 That 

November, the FAA cleared the way for 

certification of airborne windshear detectors by 

issuing Advisory Circular No. 120-41, “Criteria 

for Operational Approval of Airborne Windshear 

Alerting and Flight Guidance Systems.” ’‘ 

The crash of Delta’s L-1011 in Dallas in 

August 1985, however, provided a dramatic 

catalyst that suddenly turned the search for an 

effective weapon against the microburst into a 

top priority, organized program. In addition to 

the fact that it was the second windshear 

accident with a large number of fatalities in three 

years, the Delta crash highlighted just how 

inadequate the detection and warning 

technology still was. The Dallas-Ft. Worth 

airport was equipped with a Low Level 

Windshear Alerting System, but none of the 

system’s five sensors issued an alert until several 

minutes after the Delta airplane hit the ground. ’- 

swamped with concerned calls from constituents 

following the Dallas crash was Representative 

George Brown from California. A couple of 

Researchers aboard the 

NASA 737 during 

windshear detection 

jlight tests. 

Among the Congressmen who were 
The hazdrd that NASA 

tackled: aircrafl 

approaching a runway 

are especially at risk from 

sudden and intense 

downdrafls brought on 

by abrupt temperature 

changes. Developing 

n reliable warning system 

was the only answer. 

60 

-- 

Airborne Trtlilbhwr 

t 

weeks after the accident, Congressman Brown 

visited the Langley Research Center and asked 

for a presentation on windshear. An FAA 

manager named George “Cliff‘ Hay and Dr. 

Roland L. Bowles, a Langley research engineer, 

had been working on a plan for an airborne 

windshear detection research program for six 

months prior to the Dallas crash, but the only 

concrete research that was actually underway at 

the Langley Research Center at the time was the 

work on microburst and windshear modelling. 

Dr. Jeremiah F. Creedon, head of the new 

Langley Flight Systems Directorate, put together 

a quick briefing on the windshear problem and 

potential technologies that might be able to 

combat it. Congressman Brown asked how 

much money it would take to develop a solution. 

Nobody at 1,angley had thought that far down 

the road, but Dr. Creedon gave the 

Congressman a rough estimate of at least several 

million dollars. Brown reportedly commented 

that the amount of money Creedon had quoted 

was nothing. “It’s a lot of money if you don’t 

have it,” Creedon replied. The Senator 

whispered to an aide, and as the contingent left 

the briefing, the aide told one of the Langley 

managers that NASA had just gotten itself a 

windshear program.” 

Actually, it was not quite that simple. 

Congressman Brown, who was a ranking 

member of the House Science and Technology 

Committee, certainly had a lot of influence with 

both the FAA and NASA. But the Delta crash 

had created a tremendous amount of public and 

political focus on the windshear problem. The 

media coverage following thc Dallas accident, 

public concern, and the interest of high-ranking 

Rep resent at ives and Se ri a to rs al I helped garner 

support for a subs tan t i al , coo rd i 11 a tcd 

interagency research effort to add rcss the 

windshear problem. 

In April 1986 the FAA announced the 

formation of a National Integrated Windshear 

Plan. The plan was an umbrella program that 
incorporated numerous independent research 

efforts, some of which were already in progress.” 

Even before the Dallas crash, for example, the 

FAA had begun working on a Windshear 

Training Aid for the airlines. The project was a 

joint effort by all three major commercial 

transport airframe manufacturers (Boeing, 

Lockheed, and McDonnell Douglas), and the 

training program and techniques they developed 

to help pilots handle severe windshear situations 

proved extremely effective.” 

In addition to the training aid, the FAA 

National Plan incorporated LLWAS, research 

into an improved ground detection method 

called Terminal Doppler Weather Radar 

(TDWR), plans to improve terminal area 

communications of windshear threats, more 

detailed characterization of the windshear threat, 

and an airborne windshear detection research 

program.’’ This airborne system research 

program would be conducted by the Langley 

Research Center. In addition to its aeronautics 

expertise and the microburst modelling work 

that had already been done there, Langley had 

one other asset that made it a logical choice for 

the windshear research: a hlly instrumented air 

transport test plane, with advanced displays, that 

could take the sensor technology development 

through a test flight stage. On July 24, 1986, 

NASA and the FAA signed a Memorandum of 

Agreement formally authorizing the start of a 

joint Airborne Windshear Detection and 

Avoidance Program. A Windshear Program 

ofice was created in the Flight Systems 

directorate at the Langley Research Center, 

headed by Dr. Bowles.’* 

The FAA/NASA airborne windshear research 

program had three major goals. The first was to 

find a way to characterize the windshear threat in 

a manner that related to the hazard level it 

presented for aircraft. The second was to develop 

airborne remote-sensor technology to provide 

accurate, forward-looking windshear detection. 

The third was to design flight management 

concepts and systems to transfer that 

information to pilots in such a way that they 

could respond effectively to a windshear threat.” 

The program also had to pursue these goals 

under unusually tight time constraints. 

Part of the pressure came from the fact that 

both Congress and the general public were 

demanding a solution to the windshear threat as 

soon as possible. An even greater motivating 

factor, however, was a proposed FAA regulation 

that would greatly aid the transfer of any new 

technology developed in the NASA program if 

the research could be completed quickly enough. 

Since 1979, the FAA had contemplated 

requiring air carriers (operating under Part 12 1 

of the Federal Aviation Regulations) to install 

airborne windshear detectors in their airplanes, 

and the proposed regulation was brought up 

again after the Dallas accident. It was finally 

enacted in September 1988 and required Part 

121 air carriers to install airborne detectors in all 

their aircraft no later than December 1993. The 

minimum requirement was only for a reactive 

system, but Northwest Airlines, American 

Airlines, and Continental Airlines obtained 

exemptions that allowed them two more years to 

explore forward-looking detection system^.'^ 

In order for the technology being researched 

by the NASNFAA windshear program to have a 

real impact, the airlines, who were the ultimate 

customers, would have to support forwardlooking detection systems. Three major airlines 

had already expressed an interest in forwardlooking systems, but if NASA’s research was not 

completed until after the airlines had outfitted 

their entire fleets with reactive systems, airline 

support for the new technology would be 

greatly reduced. 

reflected a growing realization of how severe the 

microburst threat could be. The JAWS research 

in Denver in 1982 discovered microbursts too 

strong for an airplane to fly through safely, no 

matter what kind of immediate recovery 

techniques the pilots used.” In its official report 

on the 1982 New Orleans Pan Am crash, the 

National Transportation Safety Board (NTSB) 

noted that although reactive systems could help 

improve pilot performance, “programs must be 

pressed to develop airborne and ground systems 

with greater lead time predictive capabilities.””’ 

The FAA Windshear Training Aid also warned 

The emphasis on forward-looking systems 
AJat plate airborne 

rtldar used in the 

microburst windshear 

detection research 

program was housed in 

the nose of die NASA 737 

ciircrcq5. 

that the maximum windshear capability of jet 

transports in some situations was 40 to 50 knots 

wind speed change, and that “some windshears 

cannot be escaped successfully (once they are 

actually entered) .’’2’ 

Advance warning would give pilots the 

ability to increase the 

engine power and, if 

necessary, level the 

airplane before entering 

the microburst, so the 

airplane would have 

more energy, altitude, 

and speed with which 

to combat the effects of 

the windshear. Or, if 

traffic permitted and 

the shear was strong 

enough, the pilots could elect to maneuver 

around the microburst altogether. One of the 

first questions the Langley windshear researchers 

had to answer, however, was exactly how much 

advance warning was required to prevent an 

airplane from getting into a shear situation that 

it could not fly through safely. The Langley 

simulation technology program had already 

yielded significant insights about the 

characteristics of windshear and microbursts. 

The researchers integrated this information with 

analyses of aircraft energy states, tested their 

results in piloted simulations of microburst 

recovery techniques, and concluded that even 

15-20 seconds of advance warning was enough 

for an airliner to avert or survive an encounter 

with a microburst windshear. In fact, simulations 

indicated that aircraft with 10-20 seconds of 

advance warning could fly through even 

relatively strong windshears without losing any 

a1 t i tude. 

In order to allow the pilots to take 

appropriate corrective action, however, the 

warning had to convey how much of a hazard 

the impending shear posed for the airplane. 

Some windshears could be penetrated safely with 

only small power additions; others were more 

dangerous and required immediate full thrust or 

evasive maneuvers. The solution devised by 

Roland Bowles, manager of the Langley 

windshear program, was a hazard index that he 

called the “F-Factor.” 

The F-Factor was a dimensionless number 

that interpreted the vertical and horizontal 

strength of a windshear in terms of the amount 

of climb performance it would take away from 

62 Airborne Ibailbhzer 
the airplane. Or, to put it another way, the FFactor of an windshear would indicate how 

much excess power an airplane would have to 

have to fly through it without losing airspeed or 

altitude. A typical twin engine jet transport 

plane, for example, might have engines capable 

of producing .17 excess thrust on the F-Factor 

scale. So if a windshear registered higher than 

.17, the airplane would not be able to fly 

through it, even at full power, without losing 

airspeed or altitude. Information from past 

windshear accidents indicated that the warning 

threshold for most jet transports in landing or 

take-off configurations should be an F-Factor of 

.1. Consequently, a cockpit warning display 

could be preset to only show alerts for 

windshears with an F-Factor of. 1 or more to 

eliminate nuisance or unnecessary warnings.”’ 

The invention of the “F-Factor” was an 

important step in the development of windshear 

detection systems, because it provided a way for 

information from any kind of sensor to be 

presented to the pilot in a relevant and easily 

understood form. But the hazard index was only 

one of five basic requirements the windshear 

research team at Langley had identified for an 

effective forward-looking detection system. The 

technology also needed to identify hazards while 

rejecting non-threatening information, locate the 

position and track the movement of a potentially 

dangerous air mass, and annunciate the hazard 

to the flight crew. In addition to an “F-Factor” 

type of hazard index, the display also needed to 

provide information on the proximity and 

volume of the windshear.” 

By 1986, Boeing and the Sperry Corporation 

were already in the process of developing reactive 

airborne windshear systems that would alert 

pilots to windshear once it was actually 

encountered. But technology with the capability 

the Langley researchers wanted, especially in a 

forward-looking system, did not yet exist.” In 

fact, although the NASNFAA windshear 

program listed the design of forward-looking 

windshear detection systems as one of its three 

primary goals, it was still not known whether 

such technology was even possible. The 1983 

National Academy of Sciences (NAS) report on 

“Low-Altitude Windshear and Its Hazard to 

Aviation” discussed three different potential 

techniques for remote sensing of windshear, but 

found problems with all three that made them 

impractical.” Even the 1986 memorandum of 

agreement that 

initiated the FAAJ 

NASA windshear 

program noted that 

“there is no assurance 

that a practical 

airborne fonvardlooking system 

capable of detecting 

both wet and dry 

severe windshear 

‘microbursts’ can be 

achieved. ”” 

Despite their drawbacks, the fonvardlooking technologies that seemed to have the 

most potential were the microwave Doppler 

radar, Doppler light detecting and ranging 

(LIDAR), and passive infrared radiometry 

systems discussed in the 1983 NAS report. 

Microwave Doppler radar operated by 

transmitting radio waves of uniform frequency 

ahead of the airplane. 

The waves would be “- 

plane when they hit 

water particles, and 

the frequency shift of 

the return signal 

would indicate the 

direction and velocity 

of the raindrops and, 

therefore, the wind. 

Just as the whistle of a 

train would be a high 

Close-up of the sidemounted infrared sensor 

used in the windshear 

detection program. 

\ reflected back to the -LE 

pitched noise as it 

approached and would become a lower and 

lower pitched sound as it went further away, the 

frequency of the radar return signal differed in 

direct proportion to the speed and direction of 

the water particles. If they were coming toward 

the airplane, as in the case of a headwind, the 

frequency would be high. If the particles were 

going away from the plane, the frequency would 

Close-up of the Light 

Detection and Ranging 

(LIDAR) radllr mounted 

on the lower$seLage. 
During the microburst 

windshear detection 

research laser beams, 

shown here, were used to 

align the optical 

hardware of the infrared 

and LIDAR systems. 

I 

be proportionately lower. A variation of the 

frequency, and therefore the velocity and 

direction of the water particles, would indicate 

the presence of a windshear. 

The Terminal Doppler Weather Radar 

(TDWR), which was a microwave Doppler radar 

system, was proving very effective in ground 

detection of windshear, but there were several 

problems with trying to adapt the technology for 

an airborne system. First, the ground Doppler 

radars were much larger and more powerful than 

the size equipment that would fit on an airplane, 

so an airborne version might not be as effective. 

The radar would also be looking not only ahead, 

but also down toward the ground as the airplane 

descended. As a result, the radar would be 

reflected off objects on the ground, creating 

“clutter” in the return signal. In addition, not all 

microbursts contained rain, and microwave 

signals typically received few returns from dry 

air. 

manner as Doppler radar, except that it used a 

Doppler LIDAR operated in much the same 

laser light beam instead of radio waves. The 

LIDAR system also used reflections off tiny dust 

particles in the air instead of raindrops to 

determine wind direction and velocity. The size 

of existing LIDAR equipment posed a potential 

problem for its use in an aircraft environment, 

but the biggest concern about LIDAR was that 

its signal tended to be absorbed by raindrops. 

Consequently, its signal was weak, or 

“attenuated,” in the presence of the kind of 

heavy rain that was often found in thunderstorm 

microbursts. 

Passive infrared radiometry was based on the 

premise that since microbursts were formed by a 

column of cooler, rapidly descending air, their 

presence would be marked by a sharp 

temperature shift in the air ahead of the airplane. 

The technology was simpler, less expensive and 

lighter than the other systems, but it had several 

potential problems. First, there was no firm 

evidence that microbursts or gust fronts were the 

only weather phenomena containing 

temperature shifts, so there was a potential 

64 Airborne Trailbhzr 
problem of nuisance alerts with an infrared 

system. Even if the nuisance alert problem was 

solved, there would have to be a direct 

relationship between the amount of temperature 

change and the severity of the windshear in order 

for the system to be an effective warning device.34 

To try to overcome the technical obstacles to 

the different types of forward-looking airborne 

sensors, NASA enlisted the help of several 

industry manufacturers. Lockheed Missiles and 

Space was given a contract to develop an 

airborne forward-looking LIDAR detection 

system, and funds from NASA’s Small Business 

Innovative Research (SBIR) program were 

awarded to a Boulder, Colorado, company 

named Turbulence Prediction Systems to 

develop an infrared radiometry sensor. 35 

was developed by the researchers at Langley, but 

the system’s basic component was a specially 

modified Model 708 X-band weather radar built 

by Rockwell Collins, Inc. The NASA engineers 

had developed a radar and ground clutter 

simulation model at the beginning of the 

windshear program, which they had been using 

to explore various radar design and signal 

processing methods. Their work indicated that 

by making some design modifications to the 

radar, using filtering in the signal and data 

processing, and managing the tilt of the radar 

antenna, the ground clutter problem could be 

eliminated without diminishing the radar’s 

ability to detect windshear.36 

additional warning systems that did not use 

forward-looking airborne technology. The first 

was an improved “in situ” reactive system that 

used airspeed, accelerometer, angle of attack, 

groundspeed, and other data from aircraft 

sensors to verify when windshear was actually 

encountered. Although reactive systems were 

already being developed by commercial 

manufacturers, the NASA version had more 

comprehensive, three-dimensional capabilities. A 

comprehensive and precise reactive system was 

critical to the windshear research because the “In 

Situ” detector was the “truth” measurement 

against which the accuracy of the fonvardThe radar windshear detection technology 

The NASA researchers also designed two 

looking systems would be judged. 

The final detection system was simply a 

VHF radio data link that would allow 

information from a ground Terminal Doppler 

Weather Radar (TDWR) to be transmitted to 

the airplane directly. The standard TDWR 

design transmitted the information from the 

radar to a tower controller, who then had to 

transmit a verbal caution to flight crews. Clearly, 

a data link would improve the timeliness of 

windshear warnings to any airplane landing at an 

airport equipped with a TDWR. But the NASA 

researchers also planned to use TDWR 

information, uplinked to the TSRV 737 airplane 

and processed to indicate the “F-Factor” hazard 

level of any indicated windshear, to help them 

locate microbursts for flight testing the forwardlooking sensor systems.37 

took several years. In the process, the researchers 

made extensive use of computer models and 

piloted simulations developed by engineers at the 

Langley Research Center. Potential versions of 

the different detection systems were “flown” 

against computer models of past windshear 

accidents many times to determine how 

accurately the hazards were detected and 

measured. Yet especially with tricky, unstable 

phenomena like windshear and microbursts, 

computer simulations could only go so far. In 

order to get a true sense of the accuracy and 

performance of the sensors, they had to be tested 

in actual windshear conditions. In May 1990, a 

second Memorandum of Agreement was signed 

between the FAA and NASA to support a flight 

test program for demonstrating and validating 

the advanced windshear detection systems.” 

Flight testing this particular technology 

raised some significant safety considerations, 

however. The microburst windshear that was so 

lethal to aircraft occurred only close to the 

ground. To flight test the windshear sensors, 

NASA’s 737 test plane would have to 

intentionally fly into microburst conditions at 

low altitude. At best, the tests would be intense, 

turbulent encounters with an extremely severe 

weather environment. But if the sensors 

underestimated the severity of a microburst, 

Developing the various sensor technologies 87 

Technicians service the 

tail-mounted reciever on 

the NASA 737 used in 

the windshear detection 

research project. 
Schematic of microburst 

windshear and its threat 

to aircraj. 

I: During a landing a 

phne entering a 

microburst encounters 

head winds that increase 

airspeed. To maintain 

airspeed and rate of 

descent the pilot will 

normal4 reduce power. 

The phne.flies through 

tlw headwind and 

2: encounters a 

do wndr~~~f;,llo wed by a 

.j: tdjluiind 7%iJ.<e ra,bid!y 

reduce airspeed and climb 

potentinl nnd, hrrause of 

the eiirlier cut in powrr; 

cnw rl~use tlw plane to 

crnsli. 

66 

He 

there would be much less margin than usual to 

correct for the error. 

To minimize the risks, the researchers at 

Langley conducted an unusually thorough 

examination of the flight tst plan before it was 

approved. First, research pilots “flew” possible 

flight test scenarios in the Transport Systems 

Research Vehicle (TSRV) fixed base piloted 

simulator to establish operating procedures with 

adequate safety margins. After experimenting 

with numerous parameters and procedures, the 

researchers drew up a list of guidelines to ensure 

flight safety during the tests. The first was to 

minimize weather exposure. The team would 

work with isolated thunderstorm cells, but 

would avoid cells embedded in frontal systems. 

Furthermore, although the penetrations would 

be flown by the safety pilots in the fonvard flight 

deck, who could see the actual conditions the 

airplane was encountering, they would be guided 

by the pilots monitoring the electronic 

windshear and navigation displays in the 737’s 

experimental aft flight deck (AFD). Before each 

microburst was entered, the AFD pilots would 

give the safety pilots an escape vector in case the 

cell was stronger than exlxcted. Ground 

obstacles that might be a factor at low altitudes 

would be programmed into the moving map 

display in the aft cockpit, as well, so the crew 

there could make sure the airplane stayed clear of 

them.“ 

eliminated, however. It was going to be 

impossible to condiict niicroburst experiments, 

for example, without running some risk of a 

lightning strike. ’l’he biggest danger posed by 

lightning was that a spark might ignite the 

airplane’s fuel, triggering a catastrophic 

Some weather risks could not be completely 

Airborne 7Fdbhizer 

explosion. So before the flight tests began, 

NASA called in specialists to thoroughly inspect 

and seal the 737’s fuel tanks and system. 

Lightning could also severely damage the 

research equipment on board the airplane, so 

Langley technicians tried to harden the 

equipment against strikes as much as possible. 

While lightning still posed a threat to some of 

the equipment, the researchers felt the risks had 

been reduced to an acceptable level.”’ 

Second, the researchers set firm operating 

limits for microburst penetrations. For cells with 

an “F-factor” greater than .1, they set a 

minimum flight altitude of 750 feet above the 

ground and a minimum indicated airspeed of 

2 10 knots. Microbursts with an F-factor greater 

than .15 would be avoided. The plane would 

also stay clear of weather cells with extremely 

high levels of “reflectivity,” or dense 

precipitation, to minimize the risk of hail 

damage. Even in less dense rain, however, the 

igniters in the 737’s JT8D jet engines would be 

left on to minimize the chance of a flame out 

due to water ingestion. The researchers also 

planned a phased approach to the microburst 

experiments, stxting with mild shear conditions 

and working up to the more severe storm cells. 

Third, an extensive training program was 

developed for pilots and researchers who would 

be taking part in the flight tests. Flight crews 

were put through literally hundreds of simulated 

w i nds hea r pen et ra t i o 11s so they coul d p rac t i ce 

appropriate res po nscs. Th e f1 i gh t ;in d resca rc h 

crew then underwent two weeks of rehearsal 

flights in the vicinity of the Langley liesearch 

Center and the Wallops Flight Facility before 

the team deployed for the actual microburst 

experiments . 
The 737 was outfitted with some additional 

equipment for the windshear flight tests. The 

radar sensor used the flat plate Doppler weather 

radar that was already in the nose of the airplane, 

but a whole pallet of processing equipment for 

the system had to be installed in the cabin. The 

LIDAR also required a pallet of equipment in 

the cabin, in addition to a sensor that was 

attached to the underside of the 737’s fuselage. 

The infrared sensor was installed in a window on 

the left side of the plane. Changes were also 

made to the research flight deck to allow the 

windshear data to be displayed. The electronic 

map and primary flight displays in the left seat 

position of the aft cockpit were left alone, but 

three of the cathode ray tube (CRT) screens on 

the right side were modified to display windshear 

information, and two additional CRT displays 

were installed above the standard instrument 

panel. Each of the two monitors above the 

instrument panel could be configured to show a 

real-time forward-looking image from a 

television camera in the nose of the plane, the 

radar sensor display or the LIDAR sensor 

display. Another CRT screen showed 

information from the infrared and in situ 

sensors, and two additional monitors displayed 

the data linked information from the TDWR. 

The display formats were created primarily 

by Langley engineers. Sensor data from the 

infrared and in situ detection systems was 

displayed in simple bar graphs indicating the 

“F-factor” level of the hazard. The radar and 

LIDAR sensors were capable of detecting a much 

more comprehensive picture of the airspace 

ahead of the airplane, however, so the 

information from those sensors was processed 

into graphic, multi-color displays, coded to 

indicate levels of windshear severity. If the 

sensors detected a windshear over a .1 threshold, 

both displays would highlight the threat area 

with either a box, in the case of the radar display, 

or a diamond in the case of the LIDAR. The 

highlighted area would also display the 

numerical “F-Factor” of the shear, and a large 

“ALERT” signal would appear on the screen. 

The TDWR displays, which were the 

primary navigation aids in finding microbursts, 

integrated all the windshear detection 

information. The basic TDWR display would 

indicate microburst hazards with oval, race trackshaped icons. The icons were color coded, 

depending on the severity of the microburst, and 

a numerical indication of the F-factor of each 

particular microburst accompanied the icons. 

When the radar or LIDAR forward-looking 

sensors detected the shear, the warning box or 

diamond, with the F-factor, would be replicated 

on the TDWR screen. Warnings from the 

infrared sensor were displayed in numerical 

format in a corner of the TDWR screens. 

When the airplane actually entered the 

microburst and the in situ sensor detected an 

F-factor hazard over a .1 threshold, a red dot 

appeared over the microburst icon on the 

TDWR displays. The accuracy of the fotwardlooking sensors could be verified by comparing 

the numerical data recorded from all five of the 

sensor systems.” 

The initial flight tests were conducted during 

the summer of 199 I, in Orlando, Florida, and 

Denver, Colorado. The locations were picked for 

two reasons. First, Orlando and Denver each had 

an TDWR system in the vicinity of the airport. 

Second, microbursts in Orlando tended to be 

“wet” cells, while a majority of those in Denver 

How the microwave 

detection system works. 

Microwave radar emits 

radio waves at a uniform 

jkquency and wavelength 

that are rejected back by 

raindrops. The returning 

signals 'frequency is 

measured and compared 

with the emitted 

frequency to determine 

the direction and speed of 

the raindrops. A Doppler 

reading of varying 

wavelengths can indicate 

a wind shear condition. 

A: The raindrops borne 

by headwinds return a 

shorter wavelength. 

B: The raindrops borne 

by tailwinds return a 

longer wavelength. 
68 

were “dry.” By flight testing the sensors in both 

places, researchers could find out how well each 

system performed across a full range of 

microburst conditions. 

The LIDAR equipment was not yet ready for 

flight testing in 1991, however, so the initial 

experiments involved only the radar and infrared 

systems. The first tests took place around the 

Orlando International Airport from June 10th 

through June 20th. A team of more than 50 

researchers, technicians, and meteorologists was 

involved, including researchers from the 

Massachusetts Institute of Technology’s Lincoln 

Laboratory, who operated the Orlando TDWR 

equipment. 

On a typical flight day, the research team 

received its first weather briefing in the late 

morning, since microbursts typically did not 

develop until the afternoon or evening hours. 

After the briefing, the researchers often had to 

endure hours of waiting before the right weather 

conditions materialized. When the 

meteorologists saw promising signs of 

microburst activity, the flight crew of nearly 

30 researchers and pilots boarded the 737 and 

took off. 

The flight operations themselves were 

complicated, because in order to use the TDWR 

to help locate microbursts, the NASA plane had 

to stay in the immediate vicinity of the airport. 

The researchers discussed the flight test plans 

and procedures with the airport air traffic 

controllers in advance, but the flight crew still 

had to stay in constant communication with 

controllers throughout the flight to avoid 

conflicts with other airport traffic. The crew also 

had to be in constant contact with the TDWR 

ground personnel for microburst and other 

weather information. Added to these 

communications were numerous other 

conversations over the airplane’s internal 

intercom between the two flight decks and 

between thc different rcscarch stations and the 

crew viewing the displays in the aft flight deck. 

Communication was actually one of the toughest 

challenges of the flight tests, as the work often 

required as many as five different voice channels 

to be active at the same time. 

Airborne Trailbhzer 

A test run began when the ground TDWR 

personnel notified the flight crew of a potential 

microburst target. Lee H. Person, the primary aft 

flight deck pilot for the 737 throughout its 20 

years at the Langley Research Center, usually 

flew the airplane onto a final approach path to 

the microburst, because he had the advantage of 

the CRT navigation and TDWR displays. The 

team had to maneuver quickly, because 

microbursts were a short-lived phenomenon, 

lasting only five to 10 minutes. On 

approximately a two mile final approach to the 

microburst, Person would turn control of the 

airplane over to research pilot Kenneth R. 

“Dick” Yenni in the forward cockpit. Yenni, like 

Person, had been with the airplane since it 

arrived at NASA and was the primary safety pilot 

on the 737. Test runs were flown in level flight 

at altitudes between 750 and 1,000 feet above 

ground level, and before entering a severe 

microburst, the 737’s airspeed was stabilized at 

210 knots. The procedure was to enter each 

microburst with an indicated airspeed of 2 10 

knots and then, as the plane encountered the 

initial headwinds, add power as necessary to 

maintain at least a 21 0 knot groundspeed. That 

way, the airplane would have enough power and 

airspeed to safely transit the microburst, no 

matter how great the windshear. 

activity in the airplane became highly focused 

and intense. The forward flight deck pilots were 

watching for air traffic, obstacles and 

unacceptable conditions, such as severe 

lightning. At the same time, they were keeping 

up a running convcrsation with the air traffic 

controllers, and listening for course corrections, 

hazard and escape vector information, and 

groundspeed reports from the pilots in the aft 

flight deck. In addition to the constant reports 

they were giving to the safety pilots, the crew in 

the aft flight deck was talking continually with 

the ground TDWR personnel to make sure the 

windshear and reflectivity levels in the target 

microburst were still within acceptable safety 

limits and no other hazards had arisen. On two 

different intercom channels, researchers were 

giving status reports or positioning requests for 

As the 737 approached the rnicroburst, the 
the different sensors. Meanwhile, the weather 

around the airplane would deteriorate rapidly as 

the 737 entered the kind of rain-filled 

thunderstorm cell typical of Florida microbursts. 

The plane was buffeted by turbulence and rain 

pounded at the windows. The world outside the 

cabin became dark and threatening, lit up only 

by lightning flashes, which were sometimes so 

close the researchers could “hear thunder inside 

the airplane.” The first few times out there were 

reportedly some wide eyes throughout the cabin, 

but after a while, the flights became almost 

routine to the research crew. Even during the 

first few flight tests, however, the sensor 

monitoring, status reports, and communications 

among crew members continued uninterrupted 

through even the most turbulent storm 

encounters. 

In all the flight testing in Orlando, there 

were no “safety of flight” issues, but there were 

more than a few tense moments. Once, the 

weather conditions around the airplane suddenly 

closed in, and the 737 crew found the airplane 

headed up a blind canyon of thunderstorm cells 

that were all beyond the safety limits set for the 

flight experiments. Fortunately, the safety pilots 

found a slightly lighter section of clouds between 

two cells and were able to steer the plane 

through the hole without incident. On several 

other occasions, the plane came close to being 

hit by lightning, but it never actually took a 

lightning strike. It did, however, run into hail in 

one of the more severe microbursts it penetrated. 

Following the Orlando experiments, the 

plane and its research crew travelled to Denver 

Colorado for two more weeks of flight testing on 

July 8 - July 24, 1991. The flight tests were 

staged out of Denver Stapleton Airport and used 

the NCAR “Mile High” Doppler ground radar 

in nearby Boulder to help locate the microbursts. 

The procedure was similar to that followed in 

the Orlando tests, although the conditions were 

expected to be somewhat different. The 

researchers were hoping to encounter “dry” 

microbursts in Denver, which would present 

severe windshears without the heavy rainfall of 

the Florida storm cells. Unfortunately, the 

weather refused to cooperate. The only 

To obtain the ddta 

required, NASA 

windshear researchers 

intentionaLyflew in 

conditions most pilots 

try to avoid. 
windshears the researchers found in the two 

weeks at Denver were generated by gust fronts. 

The gust front shears were still quite strong, 

however, and they caused some unique flight 

conditions. Several of the fronts threw up dust 

clouds from the ground, and some of the 737’s 

low-level test flights were at or below the tops 

of the dust clouds. As a result, the research crew 

found that they had discovered a new and 

unusual way to get the bottom of the airplane 

dirty. 

The results of 

I the 1991 flight 

experiments 

showed that the 

forward-looking 

radar detection 

system successfully 

identified and 

tracked high hazard 

- areas in flight, 

although the low 

moisture 

; I ,-llu 

i 

\ 

T/J~ Lizngkey crew 

bonrdin‘g the Boring 737 

resc./lrcl, nirrrcfi in 

prcpnriztion .fir ii 

windshenr detertionflgbt 

nt Orkindo, Fhridii. 

microbursts that were expected to present the 

greatest challenge to radar were not tested. The 

in situ warnings also correlated well with the 

other detection systems. The infrared sensor did 

not fare anywhere near as well, but another 

round of flight experiments was scheduled for 

the summer of 1992, when the LIDAR 

equipment would also be tested.” 

The 1992 flight tests very nearly did not 

happen, however. The plan was to repeat the 

basic 1991 schedule, with flight tests first in 

Orlando and then in Denver. Everything was 

going according to schedule until two months 

before the Florida tests, when several problems 

arose that should have cancelled the entire 

summer’s test flights. First, both of the 737’s 

engines developed problems and had to be 

overhauled or replaced. Then, even before the 

engine work had begun, maintenance 

technicians discovered some de-bonding in 

certain lap joints of the 737’s fiiselage skin. This 

sanie problem had caused an Aloha Airlines 737 

to lose a section of its fuselage in flight, so the 

NASA airplane was grounded until all the 

affected areas could be riveted together. This was 

a major maintenance project, and under 

ordinary circumstances, the airplane would have 

been down for several months.” But this was not 

an ordinary airplane or program. 

Throughout the history of the flight research 

program at Langley, the 737 and its research 

projects had attracted a unique type of person. 

Taking research all the way to flight required 

much more detail work and presented a lot of 

unknowns and obstacles that were never 

encountered in laboratory tests. Projects that 

included flight testing also forced researchers to 

focus on real world, practical applications of 

their ideas. It took an enthusiastic, pragmatic 

and resourceful person to enjoy working on 

flight test research programs, and the people who 

worked with the TSRV 737 were often 

characterized as having an energetic, “can do” 

attitude about their projects and the airplane. 

But the power of their resourcefulness and 

dedication was never more evident than in the 

1992 windshear test program. 

When the 737 technicians and researchers 

got the bad news about the airplane, most people 

assumed the summer windshear experiments 

would have to be cancelled. That would set the 

research back a full year, since microbursts 

occurred primarily during the summer months. 

In addition to being frustrating, a year’s delay 

could make it more difficult for airlines to use 

forward-looking detection systems, because it 

would leave little time for industry to 

incorporate the technology before th e FAA 

deadline for installing windshear detectors. 

Somc of the people involved with the 

program refused to give up so easily on the flight 

tests, however. Artie D. Jessup, an electronics 

technician who worked on the plane’s research 

systems, came up with the idea of leaving the 

research pallets and wiring in the airplane during 

the airframe repair. There was some risk that the 

wiring could be damaged during the riveting 

process, but if it worked, it would eliminate 

weeks of work. Jessup argued that the risk of 

damage c0111d be minimized, and the repair 

technicians could probably work around most of 

the experimental equipment. So the equipment 

was left in place. The determination of the 

70 Airbomr Trtrilblrrzrr 
Langley crew also seemed to rub off on the 

workers at the repair facility in Birmingham, 

Alabama, because they put extra people on the 

project, worked round the clock shifts, and 

returned the airplane a week ahead of schedule. 

Even then it appeared that, at best, the 

airplane would only be able to complete one of 

the windshear flight tests before the end of the 

summer. Although the program managers 

thought they might be able to gain a little extra 

time by conducting the Denver flight tests first, 

since the Florida microburst season tended to 

last a little longer, they were still doubtful that 

the airplane and its equipment could be ready in 

time. But then Michael Basnett, the airplane’s 

crew chief, took up the challenge. He told the 

program managers that if they could get the 

research equipment ready, he and his crew 

would do whatever it took to make sure the 

airplane was also ready in time for both 

deployments. The positive attitudes exhibited by 

Jessup and Basnett began to spread. After all, if 

the crew chief was willing to make that kind of 

commitment, with all the maintenance problems 

the airplane was having, the other team members 

decided they could do no less. A growing 

conviction began to emerge from the windshear 

team that they might just be able to get the job 

done, after all. That conviction was backed by 

the managers of the Flight Systems directorate, 

who authorized the funding and overtime the 

effort required. 

technicians worked long hours, including 

weekends and holidays, to get the airplane and 

the research equipment ready. As Dr. Bowles 

described it, “Nobody wanted to be pointed to 

as the guy holding up the program.” Problems 

that arose were handled quickly and quietly, 

with as little disturbance to other work areas as 

possible. A strong team spirit developed among 

those working on the project, and morale 

remained extremely high throughout the flight 

test program. The team even printed up colorful 

“Burst-busters’’ patches that they wore with 

pride alongside the NASA insignia on their flight 

suits. Finally, the long hours, dedication, and 

effort paid off. On July 13th, two months to the 

Over the next few weeks the researchers and 

day after the airplane arrived back at Langley 

from the Birmingham repair facility, the 

windshear team departed for 

The Denver flight tests were held on July 

14 -1 8, 1992. This time, the researchers found the 

dry microbursts they were seeking and were able to 

get solid data on the performance of all three 

forward-looking sensors. Two weeks afier returning 

to Virginia, the team flew to Orlando for a second 

round of flight tests in “wet” microburst 

conditions. The 

flight tests ran from mmmeIma 

August 11 - 25, 

1992. Aside from a 

two-day hiatus when 

the airplane had to be 

flown back to 

Langley to avoid 

Hurricane Andrew, 

the research went 

extremely well. 

Weather conditions 

cooperated, and the 

researchers were able to get excellent data on the 

radar, LIDAR and infrared systems. 

Video display of a 

windshear researchjight 

undertaken 6y the NASA 

737aircrafi in 1991. 

Although the aircraji was 

not hit by lightning, it 

came very close. 

The flight tests showed that the radar system 

accurately and reliably detected and tracked 

hazards in both wet and dry microburst 

conditions. The advance warning given by the 

radar was impressive, sometimes alerting the 

pilots to a hazard as much as a minute in 

advance. The LIDAR detected the dry 

microbursts well in Denver, but was less effective 

in the heavy rain conditions encountered in 

Florida. The LIDAR was the least developed of 

the technologies, however, and was still 

considered to hold some promise for the future. 

On the other hand, the researchers finally 

concluded that the infrared technology, was 

unable to reliably detect windshear activity. ” 

Throughout the course of the FMNASA 

windshear program, researchers had kept in close 

contact with potential commercial 

manufacturers of the technology. The Langley 

Research Center held yearly conferences to 

update industry on the progress in the program 

and made all the computer modelling and 

simulation technology developed by the NASA 
Ground rtldome lit 

Boulder, Gdorndo, 

providing datrrf;)r 

wiitdsJwiir detrctiotr 

rcwtrrrlr projrct from 

thr (htcrjir 

A twt os/) Jwric h’tw~rdi. 

researchers during the program available to any 

interested company. The Westinghouse Electric 

Company, the Bendix/King Division of Allied 

Signal Aerospace and the Collins Air Transport 

division of Rockwell International were all 

acutely interested in forward-looking windshear 

detection technology, especially since the FAA 

was going to require some kind of detectors in al 

fu ture ai rli tiers. Rep resen tat ives from these three 

companies visited Langley often and talked to 

researchers almost weekly over the telephone. 

Consequently, the manufacturers knew as much 

about the technology as the NASA researchers by 

the time the test flights were completed. In 

perhaps the most telling measurement of the 

program’s success, all three companies had 

commercial radar-based forward-looking 

windshear detection systems almost ready for 

FAA certification less than a year after the NASA 

windshear research was completed.“’ 

was an almost classic example of a successful 

governmendindustry research effort from the 

very start of the project. Like many of the early 

National Advisory Committee for Aeronautics 

(NACA) research projects, it was a very focused, 

mission-oriented program that took a proven, 

significant threat to aviation and air 

transportation and developed new technology 

that could defeat it. At the same time, the 

windshear program illustrated how complex a 

technology development effort could be. The 

program structure was a joint venture between 

NASA and the FAA, and the airborne detection 

program was only one component of an even 

bigger National Integrated Windshear Plan. 

Within NASA itself, the program involved 

numerous different research directorates, 

including electronics, engineering, aeronautics, 

and flight systems. In addition, the program 

involved researchers from industry and 

academia, as well as agencies like the National 

Center for Atmospheric Research (NCAR). 

The windshear research itself was also 

complex. It incorporated physics, meteorology 

and engineering and consisted of theory, 

analysis, simulation, and flight testing. The work 

also had to be completed in a relatively short 

period of time. In addition, the flight tests were 

unusually demanding, and in order to complete 

them successfully, the researchers had to pull 

together as a team to overcome some significant 

obstacles. Yet despite the difficulties, the research 

was highly successful. There were several 

scientific and technological breakthroughs made 

during the windshear program, including the 

invention of the “F-factor” and the development 

of a Doppler radar-based ,forward-looking 

In fact, the NASA/FAA windshear program 
windshear detector. As a result, the program was 

able to develop new technology to finally tame 

the microburst windshear threat. Furthermore, 

since the NASA engineers had worked with 

potential commercial manufacturers of the 

technology from the start of the program, the 

transfer of the technology occurred smoothly, 

quickly, and effectively. 

Of course, there were other factors that 

influenced the success of the windshear program, 

as well. The research might not have been done 

at all, and certainly would not have been 

completed in such an expeditious manner, if it 

had not been for the airline accidents in New 

Orleans and Dallas and the public and political 

pressure that followed them. By the same token, 

no matter how impressive or worthwhile the 

research results were, the information might not 

have been applied quite as quickly by industry 

manufacturers if it had not been for the FAA 

regulation requiring airliners to install windshear 

detectors. The FAA regulation created an 

automatic market for windshear detection 

technology, which made commercial companies 

more willing to develop forward-looking 

detection systems. The manufacturers still had to 

compete with reactive systems, but they did not 

have to argue the basic cost-benefits of 

windshear detectors. 

The NASA 737 also played an important 

role in gaining acceptance for the forwardlooking detection systems among manufacturers 

and airlines. The fact that the windshear research 

included flight tests in the 737 meant that the 

technology was developed further than if the 

program had been limited to computer 

simulations. Consequently, there was a much 

smaller gap for the manufacturers to close 

between the NASA research effort and the 

commercial applications of the technology. In 

addition, the NASA test data, collected in a 

transport airplane and in realistic microburst 

conditions, presented unassailable proof that an 

airborne Doppler radar could reliably and 

accurately detect windshear 40 seconds or more 

before the airplane entered it. This conclusive 

evidence gave both the manufacturers and their 

customers a critical boost of confidence in the 

new technology. 

The 737 flight tests were only the final, 

visible step in a complex, seven-year research 

effort, however. Without the wide diversity of 

research talent both at the Langley Research 

Center and in the companies, universities, and 

other government agencies that participated in 

the program, the support of managers at NASA 

and the FAA, and the remarkable dedication of 

all the research team members, the flight tests 

would not have happened. In recognition of the 

extraordinary effort put forth by those involved 

and the significance of what they achieved, the 

NASAIFAA airborne windshear research 

program was nominated in 1992 for a Collier 

Trophy - the highest honor an American 

aviation research effort can receive. Industry 

evaluations of the program by NASA’s 

Aeronautics Advisory Committee were full of 

praise, describing the research effort as a “perfect 

role for NASA in support of national needs” and 

“NASA at its best.”” The windshear research 

team at NASA agreed. “This was the best we can 

do,” Dr. Creedon said. “We might get that good 

again, but we can’t get any better.” 4x 

Chapter 6 

Lej-A heads-up 

electronic jight dicplry 

tested at NASA j Langley 

Research Center to 

improve aircraft 

pe$ormance and sa&. 

Right-NASA Langley j 

‘j?ying kiborato y ” at 

sunset. 

Improving Arcraft Systems 

hen the NASA Terminal Configured 

WV ehicle (TCV) program began in 1973, 

the goal was to develop airborne systems and 

flight procedures that could improve the safety, 

efficiency, and capacity of terminal, or airport, 

operations. As the program evolved into 

Advanced Transport Operating Systems 

(ATOPS), the research expanded. Instead of 

concentrating only in the terminal area, the goal 

became improving the 

Energy Control System (TECS) allowed aircraft 

to fly more efficiently and comfortably by 

integrating autopilot and autothrottle controls. 

An Engine Monitoring and Control System (EMACS) showed that safety could be increased 

and pilot workload decreased by redesigning 

engine instrumentation displays. A Takeoff 

Performance Monitoring System (TOPMS) 

provided pilots with visual information on the 

efficiency and safety of If 

flight operations 

throughout the 

National Airspace 

System.’ One area the 

NASA researchers 

targeted to help 

accomplish this goal 

was the development of 

more capable and 

efficient aircraft 

systems. 

The ATOPS 

program and the Boeing 737 Transport Systems 

Research Vehicle (TSRV) conducted several 

different technology research projects during the 

1980s and early 1990s that were geared toward 

improving the internal systems and operation of 

transport aircraft. A Digital Autonomous 

Terminal Access Communication (DATAC) 

data bus and experimental optical engine control 

technology offered improved control and 

operation of basic aircraft systems. A Total 

progress of a takeoff 

roll to help them 

make the critical 

“Go/No Go” 

decision. 

All these 

technologies offered 

significant 

improvements in 

various aspects of 

aircraft systems and 

operations - at least 

in theory. Yet while 

the research results 

for all the technologies were positive, the degree 

to which they were incorporated into 

commercial aircraft varied widely. DATAC was 

so well accepted that it became the basis of an 

industry design standard. TECS was 

incorporated into a remote piloted vehicle 

designed by the Boeing Commercial Airplane 

Company, but it was not designed into any of 

the company’s transport aircraft. E-,WCS was 

not immediately adopted by the air transport 
Briefing concept for 

Langley? research effort 

to develop a takeof 

pelfDrmance monitor 

industry, but the technology was enthusiastically 

accepted by a general aviation manufacturer, and 

it garnered enough industry interest to make it a 

potential addition to future transport aircraft 

designs. TOPMS, on the other hand, was 

popular with pilots but was not widely 

supported by the commercial air transport 

airframe manufacturers or airlines, although 

McDonnell Douglas decided to research the 

technology further to see if its deficiencies could 

be resolved. 

The ATOPS research showed several ways 

technology could improve aircraft systems. But it 

also illustrated the complexity of the technology 

application process. To a researcher at NASA’s 

Langley Research Center, a technology with 

improved performance was clearly better than an 

old method. But the commercial manufacturers 

and ‘iirlines who would use the technology had 

to take more complex factors into accoiint. Just 

because a technology appeared worthwhile to 

researchers did not necessarily mean that 

manuhcturers or the airlines would view it the 

same way. 

DATAC 

The ATOPS program did not actually 

conduct any dedicated research into data bus 

design. But in 1983, the aerospace engineers 

who were responsible for the 737’s research 

systems began looking for a better way to 

integrate the various system components. To 

make the experimental systems work, the flight 

control, navigation and display computers and 

any experimental equipment being tested on the 

airplane had to coniniunicate with each other. 

Up until that point, each separate computer or 

component that needed to exchange information 

with any other system or equipment had to 

have a dedicated wire for each connection. In 

other words, if a computer had to give 

i n fo rni a t i o 11 to t h rec other co m po ne n ts and 

receive info r nia t io n from th ree others, it had to 

have :i total of six cables connected to it. ‘This 

limited the number of clel-nents that could be 

integrated into the system, and made the 

installation of any experimental equipment a 

time-consuming job. 

76 
David C. Holmes, who was chief engineer of 

the Experimental Flight Systems Section (EFSS), 

came across an experimental concept that he 

thought might be a great improvement to this 

cumbersome system. The new technology, called 

Digital Autonomous Terminal Access 

Communication (DATAC), was being 

developed at Boeing by an engineer named Hans 

Herzog. It was a design for a single, global data 

bus that would carry all the information between 

the different components of the airplane systems. 

The data bus consisted of a single twisted pair of 

wires, to which all the components that needed 

to exchange information were connected. Instead 

of mechanical splices, all the coupling was 

magnetic, and each “box” or computer needed 

only a single clip connection to the data bus. To 

keep the data from each component from getting 

jumbled with the other information being 

exchanged, each component’s data was coded 

and “broadcast” in a synchronized order. All the 

information was transmitted on the data bus, 

and each computer or component could be 

programmed to pull off whatever information 

it needed. ’ 

The DATAC system was a perfect design for 

the NASA 737. It would allow a far greater 

number of components to be integrated into the 

aircraft systems, and it would greatly reduce the 

amount of time required to add or exchange 

experimental equipment. Since the data bus had 

fewer wires and components, it would also be 

lighter and would require less maintenance than 

a conventional system. The only problem was 

that in 1983, DATAC existed in concept only. 

Herzog was working with it in a lab at Boeing, 

but the technology was far from fully developed. 

Nevertheless, Holmes presented the potential 

benefits of the system to William E. Howell, 

who was the chief of the Langley ATOPS 

program at that point, and Howell approved 

the idea.’ 

Putting experimental equipment on the 

TSRV airplane was nothing new. But this case 

was different. The data bus was part of the 

airplane’s basic infrastructure. If it did not work, 

none of the experimental systems, including the 

navigation, flight control and display computers, 

would be able to function. In addition, there was 

a time element to be considered. The 737 was 

expected to be grounded for the upgrade and an 

engine repair for about a year. But that was not 

very much time to develop the technology for a 

new data bus, build aircraft-compatible 

equipment, design whatever software it needed 

to operate and install it in the airplane. If the 

airplane was ready and the data bus was not, it 

would set all the ATOPS research projects 

behind schedule. Yet the potential benefits 

seemed worth the risks involved. 

became a joint effort between Boeing and 

NASA. Herzog and his team designed and built 

the data bus itself and the terminals that 

provided the interface between the data bus and 

the computers or components using the system. 

NASA engineers designed interface boxes and 

sofnvare that would convert the data from the 

format needed for transmission on the data bus 

to a format the 737’s computers and 

experimental systems could understand. 

versions of the terminals to send to the Langley 

Research Center so the engineers there could 

begin developing the software. The Boeing 

researchers then worked on designing aircraft 

versions of the terminals, which had to be 

smaller by two thirds than the laboratory 

equipment. In the summer of 1984, after a yearlong effort, the data bus, the magnetic couplers 

and the aircraft versions of the terminals were 

ready. Herzog and several of his co-workers 

travelled to Langley with the equipment to help 

integrate it with the NASA-designed interface 

boxes and software and install the system in the 

airplane. 

fine-tuning, however, and time was getting 

short. The rest of the upgrade was nearly 

finished, and the 737 was scheduled to begin 

flight testing again in a few weeks. As a result, 

the Boeing-NASA crew spent many long hours 

in Langley’s Experimental Avionics Simulation 

and Integration Laboratory (EASILY) working 

out bugs in the system, including one 

memorable weekend when the power went out 

The development of the DATAC data bus 

Boeing first had to create crude laboratory 

The equipment still needed a fair amount of 
in the building. Time was too precious to wait 

until maintenance crews could fix the problem 

Monday morning, so the crew set up a generator 

in the parking lot and continued working with 

flashlights and small work lights throughout 

the weekend.’ 

was installed and working in the airplane. The 

737 made an excellent test bed for a new data 

bus, because the equipment in the front cockpit 

remained conventional. If the DATAC system 

had ever developed a problem in flight, the safety 

pilots could have taken over and flown the 

airplane. The system never had any such 

problems, however. The Langley engineers and 

technicians were extremely pleased with its 

operation and reliability, as well as the ease with 

which new experiments or systems could now be 

integrated into the airplane. 

In September 1985, after the DATAC 

system had flown on the 737 for over a year, a 

team of engineers working on Boeing’s new 

transport design, designated the “7J7,” visited 

Langley to look at some of the new technologies 

the ATOPS program was exploring. Howell was 

giving them a demonstration of the equipment 

on the TSRV airplane, when one of the 

engineers asked if DATAC was being used for 

data recording. Howell told him it was being 

used not only for data recording, but for the full 

experimental flight control system. The Boeing 

engineers became more interested, and asked 

how many problems the NASA crew was 

experiencing with the data bus. “None,” Howell 

replied. In that one simple interchange, a 

significant amount of the NASA work on 

DATAC was successfully transferred to 

industry.’ 

Boeing actually owned the DATAC 

technology. But the system might not have been 

developed enough to use in the 7J7 design had 

NASA not supported Herzog’s work. By the 

same token, the design team working on the 7J7 

might not have had the confidence to use a 

d ra ni a ti call y n cw tec h n 01 ogy for so me th i ng as 

important as the basic system architecture of a 

new airliner if it had not proven itself first on the 

TSRV airplane. Although the 7J7 was never 

By the beginning of August 1984, DATAC 

Airborne Trdokzer 

built, the DATAC technology was incorporated 

into Boeing’s next jet transport design, the 

B-777. 

DATAC worked so well, in fact, that 

Aeronautical Radio, Inc. (ARINC) used it as the 

basis of a new industry data bus standard. 

ARINC is a not-for-profit organization owned 

and supported by the airlines that sets standard 

specifications for technology, so the products 

developed by different manufacturers will be 

compatible with all commercial transport 

aircraft. The specification for the new data 

bus, called ARINC 629, was adopted in 

September 1989.” 

The DATAC research was a somewhat 

unusual joint partnership between Boeing and 

NASA. The bulk of the development work was 

done by a Boeing engineer, and the work was 

supported by NASA primarily because the data 

bus could give NASA’s own B-737 test airplane 

enhanced capability. In the process, however, the 

TSRV 737 played a crucial role in gaining 

acceptance for the data bus in not only Boeing’s 

newest airliner, but the entire next generation of 

transport airplanes. 

OPMIS 

Six years after the DATAC system was 

installed on the 737, the ATOPS program 

researchers began working on a joint project 

with the McDonnell Douglas Aircraft 

Corporation that showed potential of someday 

usurping the ARINC 629 standard. The project 

was call ed the 0 p t i cal Pro pu Isi o n M a 11 agem e n t 

InterFace System (OPMIS), and it represented a 

first step toward a concept called fly-by-light 

technology. Fly-by-light systems would use fiber 

optic cables instead of electrical wires to transmit 

signals to operate the flight and engine controls 

of an airplane. 

Fiber optic technology had several potential 

advantages. The most significant one was that it 

coil Id eli ni i na te pro blenis with electromagnetic 

interference (EMI) that often occurred with 

closely grouped electrical wires. Fiber optic 

cables could also carry much more information 

than electrical wires, so a fly-by-light system 
I 
Heads-up visual disphys 

of the Take Off 

Pe$orrnance Monitoring 

System tested on the 

Langley 737 aircraft-. 

Left--An acceptable 

acceleration error. 

Center-An unacceptable 

acceleration error with an 

abort adviso y sign. 

Rigbt-A single-engine 

j&lure without nn nbort 

ndvisory. 

would have expanded capabilities. In addition, 

the technology was lighter weight than 

comparable electrical systems, which would 

translate into increased efficiency in aircraft 

performance. 

McDonnell Douglas had been working on 

fly-by-light technology since 1987 and wanted to 

test the concept on an airplane. The McDonnell 

Douglas engineers decided to start with a fiber 

optic engine control system, because it would be 

a manageable project and it would be safer than 

experimenting with an entire flight control 

system. Even if a fly-by-light system failed, the 

test airplane would still have at least one good 

engine and all its flight controls functioning, so 

it could land safely. 

The OPMIS project was actually a joint 

effort among several entities. McDonnell 

Douglas worked with United Technologies, Inc. 

to develop the basic fly-by-light technology. The 

big hurdle in the fly-by-light system, however, 

was the development of optical sensors to 

interface with the engine itself, and five different 

companies built experimental sensors to test 

during the research program. NASA engineers at 

Langley then integrated the OPMIS technology 

into the TSRV 737 airplane. 

OPMIS used optical sensors installed in a 

bracket on the throttle controls to pick up any 

changes in throttlc position. That change would 

be transmitted by fiber optic cable to the engine, 

where an engine controller would translate the 

optical signal to an electrical one which, through 

an actuator, would move the engine controls to 

correspond with the throttle position. Data on 

the operation of the OPMIS equipment would 

then be sent via fiber optic cables, but in the 

ARINC 629 data bus format, to the research 

pallets in the back of the 737 airplane. Although 

the point of the research was not to investigate 

data bus technology, the OPMIS research was 

the first time an optical ARINC 629 data bus 

had ever been flown on an airplane. 

technical challenges, because fiber optic cables 

had to be handled differently than electrical 

cables. Working with fiber optics required new 

techniques, as well as different connections, 

harnesses, and hardware. The NASA engineers 

also decided to incorporate shear fuses into the 

system that would allow the safety pilots to 

physically disconnect the OPMIS system from 

the engine in case of a problem or equipment 

failure. If the OPMIS equipment was 

disconnected, the engine control would revert to 

its baseline mechanical system. 

Finally, in the spring of 1993, an operational 

OPMIS system was installed on one of the 

TSRV 737's two Pratt & Whitney JT8D-7 

engines. The research flights begin in May 1993, 

and the researchers planned to fly OPMIS on the 

airplanc on all its research flights. Results would 

not be available for sonic time, but the 'TSRV 

737 was continuing to play an important role in 

cxploring the frontier boundaries of advanced 

aircraft systems. 

Developing the system presented some new 

80 
TECS 

The Total Energy Control System research 

was, essentially, an effort to make an autopilot/ 

autothrottle system perform more like an actual 

pilot. In most transport aircraft, the autopilot, 

which operated the aircraft flight controls, and 

the autothrottles, which managed the engine 

power settings, were designed as totally 

independent systems. If the pilots wanted to fly 

the airplane through its automatic controls, they 

would set a desired speed, heading, and altitude 

into a control panel. The autothrottles would 

correct deviations in speed by increasing or 

decreasing the power settings of the engines, and 

the autopilot would compensate for deviations in 

either altitude or heading by changing the pitch 

or bank angle of the airplane. 

The systems were designed separately so that 

if one failed, it would not affect the operation of 

the other. The approach was not very efficient, 

however. The autopilot functions always had 

priority so, for example, if the airplane hit 

turbulence, the autopilot would be making 

constant pitch corrections to try to keep the 

airplane on the correct altitude. The autothrottle 

had no way of knowing that the pitch changes 

were temporary, so it would continually increase 

and decrease the throttle settings to try to keep 

the speed constant. The problem was even worse 

in other situations, such as when the airplane 

was trying to stay on a descending glideslope 

into an airport. 

If the airplane was high and slow, on its 

approach, the autopilot would pitch the nose of 

the airplane down to get back to the proper 

descent path, and the autothrottles would 

increase the power settings to correct the speed. 

As the airplane pitched down, however, the 

plane would speed up, and the speed would 

increase even further because the autothrotttles 

had raised the engine power levels. Suddenly, 

the airplane would be too low and too fast. The 

autopilot would then pitch the airplane up, and 

the autothrottles would retard the engine 

settings. But that combination would cause the 

airplane to slow down too far, so the 

autothrottles would have to increase the power 

settings again. As the engines came up in power 

the airplane would start to climb, so the 

autopilot would tell the airplane to descend, and 

the whole cycle would start over again. The net 

result was that in automatic modes, the 

autothrottles were moving constantly, and the 

autopilot had to make an excess number of pitch 

adjustments. It was a system that was not only 

potentially uncomfortable, but also extremely 

wasteful of fuel. 

A human pilot intuitively took a more 

coordinated approach to controlling an airplane. 

Upon realizing he was a little high and slow on a 

descent path, for example, he would simply 

point the nose of the airplane down, correcting 

both the alitutude and speed errors without 

adding power. In doing so, the pilot would be 

using the stored energy in the airplane’s excess 

altitude and converting it into speed as he 

descended, instead of relying solely on the energy 

of the engines to adjust the airplane’s speed. 

The Total Energy Control System was an 

attempt to design a more efficient, integrated 

autothrottle/autopilot system that would make 

better use of an airplane’s stored energy. Studies 

at the Langley Research Center had indicated the 

potential advantages of such a design, and in 

1979- 198 1, NASA contracted with engineers at 

the Boeing Commercial Airplane Company to 

develop the control laws the system would 

require. After pursuing several design strategies 

that did not work, the engineers finally focused 
82 

on how the different controls affected the energy 

of the airplane. The throttle, they realized, 

controlled the energy state of the plane, and the 

elevator controlled the distribution of that 

energy from flight path to speed. 

Boeing engineers successfully completed the 

design of the Total Energy Control System 

(TECS). When making decisions about how to 

correct errors in the aircraft’s flight path or 

speed, TECS would first look at the energy state 

of the airplane. If it was correct, TECS would 

simply use the elevator to redistribute the energy 

to achieve the desired flight path or speed. For 

example, if the airplane was high and slow on an 

approach, TECS would recognize the potential 

energy in the extra altitude, and use the elevator 

to pitch the airplane down, just as a human pilot 

would. When a maneuver demanded a 

significant climb or descent rate and/or a very 

large speed change, of course, it might exceed the 

energy capabilities of the airplane. In that case, 

TECS would first insure that the engine settings 

were within the pre-set limits programmed into 

the system. It would then give priority to 

meeting either the speed or flight path target, 

depending on which mode the pilot had 

selected. In an aborted landing and go-around 

situation, for example, speed would be critical, 

so that would take precedence. If the pilot 

selected flight path priority, the airplane would 

give up speed to maintain the flight path target 

within the safety limits of the airplane’s stall and 

maximum speed limits. 

TECS was first tested in the real-time R-737 

fixed base simulator at the Langley Research 

Center. The concept worked well in simulation, 

so the NASA engineers then programmed it into 

the TSRV’s flight computers and conducted 20 

hours of flight testing with the system in 1985. 

The objective was not only to test the 

performance of the technology, but also to give 

pilots an opportunity to fly and evaluate the 

in regrated ail topi lo t/au to thro ttle sys tem. The 

flight test results showed that TECS met or 

exceeded all of its performance objectives, and 

pilots liked the system. 

Within six months of that realization, the 

Yet by 1993, TECS had not been 

incorporated into any of Boeing’s commercial 

transport aircraft, and the decision had been 

made not to include it in the new B-777 airliner 

the company was building. The primary reason 

was that implementing TECS required a 

complete redesign of the automatic control 

system. While the control laws the Boeing 

engineers used to develop TECS had been kept 

generic on purpose, to make the concept easily 

adaptable to new aircraft, designing a new 

control system from scratch would still entail 

significant costs for Boeing. In order to make 

that investment worthwhile, there would have to 

be a compelling need for the change, or 

significant cost savings involved. While TECS 

would result in he1 savings, the fuel crisis of the late 

1970s that had helped spur the start of the research 

had subsided by the mid- 1980s. The bottom line 

was that while TECS was an excellent concept, 

there was not yet a great enough need for it for 

Boeing to justify the expense of developing it into a 

commercial application. Nevertheless, Boeing 

engineers who worked on the project remained 

optimistic that a commercial transport application 

for it would eventually develop. 

Actually, an application for TECS had 

already developed, although it was not in a 

commercial transport airplane. After the TECS 

research was completed, Boeing began building a 

high altitude, long endurance, unmanned 

airplane, called the Condor, for defense and/or 

other uses, such as patrolling the antarctic for 

holes in the ozone layer. As it was unmanned, 

the aircraft had to be flown entirely on autopilot. 

Since it was also designed for maximum 

endurance, that autopilot system had to be 

operating at peak efficiency, at altitudes where 

the speed envelope between its maximum speed 

and its stall speed was only two or three knots. 

By a fortunate coincidence, one of the 

Uoeing engineers who had worked on the early 

TECS research was ;issigned to the Condor 

project. The other engineers had heard of 

TECS, but having someone on the project who 

knew the technoloby intimately helped convincc 

them to pursue it. It was easier to introduce new 
technology to the Condor project, of course, 

simply because of the aircraft’s nature. It was 

unmanned, so there was no concern about 

having to re-train pilots. There were no human 

factors problems to consider. It was already 

being designed from scratch, so incorporating a 

new control system did not entail as many 

additional costs, and it was not a commercial 

airliner, so the new control system did not have 

to be re-certified by the Federal Aviation 

Administration. 

Nevertheless, TECS still might not have 

been incorporated into the Condor if it was only 

a paper theory. The fact that the technology had 

already been successfully flight tested in NASA’s 

737 gave the Boeing designers a crucial level of 

confidence in its performance and reduced the 

risk level enough that Boeing was willing to use 

the new technology in an operational aircraft. 

E-MACS 

The advent of computers in the cockpit and 

electronic flight displays had opened up 

tremendous new opportunities for conveying 

information to pilots. In the 197Os, the TCV 

program had conducted a lot of research into 

different display formats, but the focus had been 

primarily on flight and navigation displays. In 

1987, however, a NASA researcher in Langley’s 

Aviation SafetylAutomation program, Terence 

S. Abbott, began working on a new format for 

displaying engine instrumentation information. 

The display was called the Engine Monitoring 

and Control System (E-MACS). 

more effective format for any kind of display. As 

opposed to electromechanical instruments, 

which could only present raw sensor 

information, computerized, electronic displays 

had the capability of processing that information 

into a more useful form for the pilot. 

Specifically, Abbott wanted to evaluate the 

advantages of “task-oriented’’ displays, which 

would, as the name suggested, take the end task 

the operator needed to perform with the 

information and design the display to support 

Abbott’s focus was actually on developing a 

that task. He chose an engine instrumentation 

display as an application with which to 

experiment because the tasks pilots had to 

perform with engine information were relatively 

simple, but they still involved both monitoring 

and control functions. 

The primary control task pilots had to 

perform with aircraft engines was choosing and 

setting the power level. Conventional, 

electromechanical engine instruments gave the 

pilot direct readings of the engine pressure ratio 

(EPR), which measured the difference in 

pressure between the engine inlet and outlet, the 

speed of the low pressure engine compressor 

(Nl), and the speed of the high pressure engine 

compressor (N2). The pilot would use these 

readings to interpret and adjust the amount of 

power, or thrust, the engine was developing. 

Abbott’s design, on the other hand, used a 

computer to process all that information for the 

pilot. Using a model of the engine’s performance 

and vertical bar graphics, E-MACS showed the 

pilot the actual thrust commanded (presented as 

a percentage of full take-off power), as well as the 

thrust the engines were putting out at the 

moment. 

engine monitoring functions pilots had to 

perform. To insure that the engines were 

operating properly, pilots had to constantly 

monitor readings of exhaust gas temperature, 

engine oil pressure, oil temperature, and fuel 

flow, in addition to the EPR, N1 and N2 

gauges. The conventional, round 

electromechanical instruments showed the 

numerical value for each parameter and would 

indicate if that number was in a caution or alert 

range. The only way for a pilot to detect small 

deviations from a normal reading, however, was 

to know, from past experience, what a normal 

reading at that power setting should be. Small 

deviations were significant because they were 

often early indications of engine trouble. 

The E-MACS format was based on the 

assumption that knowing the actual numerical 

value of any engine parameter was not as critical 

to the pilot as knowing whether the reading was 

The second aspect of E-MACS addressed the 
normal or not. To give the pilot that 

information, E-MACS presented the engine 

readings in a format called a "column deviation 

graph." The display represented each engine 

parameter as a separate vertical column on a 

common graph. The readings were synchronized 

so that, regardless of the actual numerical value, 

the middle line of the display represented zero 

deviation from a "normal" reading at a given 

power setting. The first 

lines above and below that 

line represented a caution 

level, and the lines beyond 

that signalled a warning 

level. The column graphs 

for each parameter would 

extend up or down from 

the middle line for any 

high or low deviation from 

the ideal value. For more 

specific information, each 

column was labelled and 

the numerical value of 

each parameter was 

displayed in digital form 

above the appropriate 

column.' 

This display had 

several potential advantages. First, it enabled 

pilots to detect even small deviations in engine 

behavior easily, before they reached a caution 

level. Second, it allowed pilots to scan all the 

instrument readings quickly and almost 

instantaneously determine if all the parameters 

were within limits. Several behavioral studies had 

indicated, in fact, that a column deviation graph 

format allowed a user to process up to 18 

different elements in the same amount of time it 

took to process one, because the entire graph was 

perceived as a single item."' 

Abbott started work on the concept in 1987 

and began tests of the system in the TSRV fixed 

base simulator at Langley in the summer of 

1988. A total of 16 NASA, airline and United 

States Air Forcc pilots participated in the study, 

which used the cathode ray tube (CRT) displays 

in the simulator to compare modern, 

conventional engine instrumentation displays 

Airbornc Trrrilblnzcr 

against the E-MACS concept. The results were 

striking. Using the conventional instruments, the 

pilots missed 43% of the engine faults 

introduced into the system. With the E-MACS 

display, however, every single fault was detected, 

no matter how small. 

In a particularly dramatic aspect of the 

experiment, the researchers introduced a similar 

kind of fault as the one identified as the cause of 

the Air Florida crash on the 14th Street Bridge 

in Washington, D.C., January 13, 1982. The 

problem on the Air Florida B-737 jet was that 

the forward probe for the engine pressure ratio 

was blocked by ice. As a result, the EPR reading 

in the cockpit was erroneously high. Since pilots 

use the EPR gauge to set the engine power, the 

pilots of the Air Florida jet thought they had full 

takeoff power when, in fact, they did not. While 

the other gauges, such as the fuel flow, N 1, and 

exhaust gas temperature, would have shown 

lower than normal readings because of the low 

power setting, they were not low enough to 

indicate a caution level, and the Air Florida 

pilots did not catch the problem in time. Using 

the conventional display format, the evaluation 

pilots in the NASA simulation study all missed 

the error, as well. With the E-MACS display, 

however, the pilots caught the problem in time 

on every single run. 

The pilots in the study reported that the 

E-MACS display was significantly easier to use 

for both engine control and monitoring, and 

they showed an overwhelming preference for the 

E-MACS format for fist detection of fault 

conditions." Clearly, the technology had 

promise. The system was put on the TSRV 737 

airplane in February 199 1 to see if it would still 

work in realistic flight conditions. Since the 

objective of the flight tests was validation of the 

basic technology only, the tests did not include 

any industry pilots. Further flight tests were 

scheduled, but the push to finish the airborne 

winds h ea r d etect i o n fl ig h t test i ng forced t h e 

E-MACS rese;irch to be rcscheduled. 

promise, the major airframe manufacturers still 

had some concern about the system's ability to 

judge ideal engine performance accurately over 

AI t h oug h the tec h n ol og show ed sign i fi ca n t 
the life of an engine. Typically, as an airplane 

engine aged, its maximum performance would 

deteriorate, so the “normal” readings would 

change. Although NASA researchers believed 

that the parameters between a “normal” reading 

on the display and a cautionary one were 

sufficiently broad enough to allow for engine 

degradation, the concern remained. 

Nevertheless, the McDonnell Douglas 

Corporation did include an E-MACS concept in 

the tentative baseline cockpit design for a future 

air transport airplane it planned to build, 

designated the MD-XX.” 

Interestingly enough, the most rapid 

application of the E-MACS concept was not in 

the air transport industry at all, but by a general 

aviation avionics manufacturer. Representatives 

from ARNAV Systems, Inc. saw a NASA display 

of E-MACS at the Experimental Aircraft 

Association annual convention in Oshkosh, 

Wisconsin in 1989. They liked the idea so much 

that they adapted the concept into a design for 

general aviation piston engines, and began 

marketing it as a component of the company’s 

MFD 5000 Cockpit Management System in 

1992. To cope with the problem of engine 

performance degradation over time, ARNAV 

developed an artificial intelligence-based 

computer program that would modify the ideal 

values as the engine aged. Although the initial 

version of the MFD 5000 did not incorporate all 

the elements of the E-MACS display, 1. it included 

the basic column deviation graph, and the 

company eventually planned to implement the 

entire E-MACS concept.” 

The E-MACS research illustrated an 

interesting aspect of technology transfer. 

Although the major manufacturers considered 

putting the technology on a next-generation 

airplane, that application process would take five 

or more years and would still be dependent on 

whether or not the technology proved itself costeffective enough to be included in the final 

cockpit design. E-MACS was accepted 

immediately and enthusiastically, however, by a 

smaller company outside the mainstream air 

transport industry. Ever since Thomas S. Kuhn 

introduced his concept of “paradigms,” theorists 

have argued that new ideas are often accepted 

first at the edges of an organization or industry. 

Smaller companies could generally move faster, 

had less inertia supporting the status quo, and 

had less to lose by incorporating new 

technologies or concepts.“ While the theory did 

not necessarily apply in every case, the rapid 

transfer of the E-MACS technology to ARNAV 

illustrated at least one example where the theory 

held true. 

A- Kansas University student 

throughout the takeoff 

roll. In 1984, Srivatsan began working with 

researchers at the Langley Research Center on 

display concepts that might be able to give pilots 

this kind of information. 

designed to be displayed on the navigation CRT 

screen in the cockpit. The pilot would input the 

airplane’s weight, the outside temperature, wind 

conditions, runway length and the basic runway 

condition (dry, wet, icy, snow-covered, etc.) into 

the flight management computer. The computer 

would then create a display of the departure 

runway that showed the predicted takeoff point 

of the airplane, the point at which the airplane 

had to rotate in order to clear a 35-foot obstacle 

at the end of the runway, and where on the 

runway the critical reference speeds should 

occur. The airspeed was displayed in digital form 

in a box beside the runway. The display also 

incorporated two moving bars that indicated the 

The basic TOPMS information was 

Disphys of incorrect 

sensor readings during 

engine power-up for 

take@ similar to that 

experienced during the 

I982 Air Florida 

accident at Washington 

National Airport. 

traditional display, 

Top- Traditional 

diplay. 

Bottom- Engine 

monitoring and Control 

System (E-MACS) 

display. Note the visunl 

superiority of E-MACS 

to warn flight crews of 

bamrd 
86 

engine pressure ratio (EPR) for each of the two 

engines. If either or both of the engines failed 

during the takeoff roll, the corresponding EPR 

bar would turn red, alerting the pilot to the 

engine problem. 

Three seconds afkr the pilot stopped 

advancing the throttles on the takeoff roll, the 

computer would compare the predicted 

acceleration of the airplane against the actual 

movement its on-board accelerometers were 

reporting. If the two rates did not agree, the 

computer would adjust its equations and show a 

new predicted takeoff point on the TOPMS 

display. During the takeoff roll, the computer 

would also be running a series of tests on the 

airplane’s condition and modifying the display 

accordingly. The first test was whether or not 

both engines had failed. If they had, not only 

would both EPR bars turn red, but a red stop 

sign would appear at the top of the display. If 

both engines had not failed, the computer went 

on to the next test, which was whether or not the 

airplane had reached the critical decision speed, 

known as V1. Once the airplane had passed V1 

speed, it was committed to the takeoff, and a 

large green arrow would appear at the top of the 

screen, indicating to the pilot that the takeoff 

should be continued. 

If VI speed had not yet been reached, the 

computer tested to see if one engine had failed. 

If an engine failure was detected before the 

airplane reached V1 speed, a red stop sign would 

appear on the screen, advising the pilot to abort 

the takeoff. If both engines were still operating, 

the computer next evaluated the acceleration of 

the airplane. If the acceleration rate was below a 

predetermined threshold, a red stop sign 

appeared on the display. If the acceleration rate 

was still within acceptable limits, the computer 

looked to see if the predicted takeoff point had 

progressed beyond the point on the runway 

where the airplane could rotate and still clear a 

35-fOOt obstacle, even if one engine failed. If it 

had, the stop sign appeared. The final test was to 

see if the predicted stopping point of the airplane 

would still be on the runway if the pilot aborted. 

Once the stopping point was beyond the 

runway, the display showed a green arrow at the 

top of the screen. If the pilot aborted the takeoff 

at any point, all the takeoff information 

disappeared, and the display indicated only the 

predicted stopping point of the airplane at its 

current deceleration rate and with maximum 

braking efforts.” 

performed in the TSRV fixed-base simulator at 

Langley. The first simulator study, conducted in 

1985-1986, consisted of 32 pilots from NASA, 

the FAA, the United States Air Force, airline 

companies, and airframe manufacturers. The 

pilots liked the display, but were concerned 

about the pilot looking down to monitor the 

information, instead of looking out the window. 

As a result of the study recommendations, the 

NASA researchers organized a second simulator 

study in 1986- 1987, in which 17 pilots were 

asked to evaluate the TOPMS on both a “headsdown display” (HDD) and a “heads-up display” 

(HUD). The pilots rated the heads-down display 

as “good” and the heads-up display as “very 

good.” All the pilots reported, however, that they 

would like to have at least a heads-down 

TOPMS display in their cockpits, because the 

information provided “valuable safety 

information not currently available during 

takeoff. ” ’“ 

Following the second simulator study, 

TOPMS was installed on the TSRV 737 to 

evaluate how well it would operate under actual 

flight conditions. In April, 1988, the ATOPS 

crew took the airplane down to the Kennedy 

Space Center to test the system on the same 

15,000 foot runway the Space Shuttle used for 

Florida landings. The researchers wanted to test 

the accuracy of the system’s predicted stopping 

points for high-speed takeoff aborts, and the 

long, wide runway at Cape Canaveral provided a 

reassuring extra safety margin. After the 

predictions proved accurate during 80 knot and 

100 knot aborted takeoff runs in Florida, the 

crew conducted similar experiments back at the 

Wallops Island flight facility in Virginia. 

Between other research projects, maintenance 

and scheduled upgrades to the 737’s 

experimental systems, however, only six days of 

TOPMS flight testing were completed over a 

Most of the TOPMS research was actually 

Airborne Trdilbhzr 
two year period. In addition, all the test runs 

were on dry runway conditions.” 

TOPMS that was attended by representatives 

from manufacturers, airlines, avionics 

companies, flight safety groups, and industry 

associations. Despite the positive reviews by the 

test pilots in the simulator studies, the industry 

response to the concept was mixed. One concern 

was that the sudden appearance of the “STOP” 

and “GO” flags on the display might be 

interpreted by pilots as a command instead of an 

advisory caution. Another concern was that the 

predicted information on the display might not 

always be accurate, because there were too many 

potential variables. For example, conditions 

could change from one end of the runway to the 

other, so although the display might indicate to 

the pilot that he had enough room to stop, that 

might not actually be the case.” 

at the workshop, Srivatsan and the Langley 

researchers conducted a third simulation study 

with six pilots in 1991-1992. This study 

evaluated three different TOPMS display 

options. The first showed a predicted takeoff 

point but had no advisory symbols and did not 

include information on the predicted stopping 

point in the case of an aborted takeoff. The 

second option was the original TOPMS display, 

and the third contained the same predictive and 

advisory information as the second option, with 

one additional feature. In the third option, the 

appearance of an preliminary abort symbol 

indicated a developing acceleration problem 

before a firm “STOP” advisory appeared on the 

screen. Four of the pilots preferred the third 

display option, while two preferred the format 

without any advisory information, although all 

the pilots reported that they would prefer any of 

the options to no TOPMS display at all.’” 

The different display formats still did not 

address the industry concern of runway variables, 

however, and one other significant problem 

remained. In manufacturing a warning system to 

be used in circumstances where the consequences 

of a missed alert could be serious, such as in a 

critical takeoff situation, the alert tolerances had 

In October 1989, NASA held a workshop on 

To try to address some of the concerns raised 

to be made very tight. Tight tolerances could 

easily lead to nuisance alerts, however. Nuisance 

alerts would not only prompt unnecessary 

takeoff aborts, which were in themselves 

somewhat hazardous, but they could also lead 

pilots to pay less attention to alerts when they 

were triggered. As a result, the pilots might 

ignore a warning in a situation that was actually 

critical, negating the value of an alert system that 

had cost a lot of money to install.’” 

In short, safety from a manufacturer’s or 

operator’s standpoint was not as simple as it 

might appear to research organizations.” 

TOPMS seemed to give pilots valuable safety 

information, and the test pilots who participated 

in the demonstration all thought it was a 

beneficial system. But TOPMS would need a lot 

more work before it would be acceptable to the 

airline industry, which had to take different and 

more complex factors into account. As a result, 

Boeing elected not to include a takeoff 

performance monitor in the B-777 design.” 

McDonnell Douglas, on the other hand, saw at 

least enough potential in the technology to 

continue internal research on the concept. Based 

on the expectation that additional research might 

be able to overcome the technology’s perceived 

deficiencies, McDonnell Douglas also included 

a takeoff performance monitor in the tentative 

baseline design for the MD-XX cockpit.” 

Summary 

The ATOPS program research into airplane 

systems showed that new technology could make 

significant improvements in the safety and 

efficiency of flight operations. The research also 

underscored, however, that manufacturers 

looked at the potential risks associated with new 

technology as much as they looked at its 

potential benefits. If the risks were low, the 

technology would probably find ready 

acceptance. But if some level of risk remained, or 

if there was not enough of a driving economic 

benefit to balance out the risk, the technology 

might not be as easily adopted, especially by the 

major industry manufacturers. 

Chapter 7 

Improving Aircrafi Operations 

eveloping better equipment and systems D for individual aircraft was an important 

step toward increasing the safety and efficiency 

of air transport operations. But the Terminal 

Configured Vehicle (TCV) program grew out of 

a realization among researchers and policymakers 

that simply improving airplane components was 

no longer sufficient. Gaining a few extra knots of 

airspeed or better efficiency in cruise flight was 

useless if the airplane was then vectored around 

for 20 minutes at low altitude because of 

terminal area congestion. Researchers needed to 

focus not only on improvements to individual 

airplanes, but also on technology that would 

allow the airplanes to operate more efficiently 

within the air traffic control system. 

Several of the TCVIAdvanced Transport 

Operating Systems (ATOPS) program research 

projects focused on flight operations in the ATC 

environment. In 1979-80, NASA researchers 

conducted experiments with a four-dimensional 

(4-D) navigation system to try to streamline 

descent and approach procedures into crowded 

terminal areas. Another research effort explored 

the use of a cockpit display of air traffic to help 

pilots maneuver more efficiently onto an 

approach course. A third series of experiments 

looked at the use of a two-way data link to 

improve and simplify communications between 

pilots and air traffic controllers. 

on concepts to increase the efficiency of landing 

operations. If technology could be developed 

Ground crew member 

directs the Boeing 737 

yying laboratory ” to its 

ramp position afier a 

research ftight at 

Orlando, Florida. 

The TCV/ATOPS researchers also worked 

that could reliably reduce the length of time an 

airplane spent landing and taxiing off the 

runway, arriving airplanes could be spaced closer 

together by air traffic controllers. Closer spacing 

would, in turn, decrease delays and increase 

capacity at airports. In one joint effort between 

the Langley Research Center and the Boeing 

Commercial Aircraft Company, engineers 

developed and tested precision flare control laws 

that improved the ability of airplane autoland 

systems to land the aircraft at a specific point 

along a runway. The touchdown point could 

then be planned to coincide with runway 

turnoffs so the airplane could land and get off 

the runway in a minimum amount of time. A 

separate research project tested the use of a 

magnetic cable buried in the runway and taxiway 

surfaces to help guide airplanes off the runway 

quickly in low visibility conditions. 

Improving the efficiency of transport 

operations within the air trafic control system 

offered significant benefits in terms of fuel 

savings and airport capacity. But improving 

operations in a system was a much more 

complex task, involving many more variables, 

than simply improving elements of a single 

airplane. Technology oriented toward system 

operations required not only the support of 

airframe manufacturers and airlines, but the 

Federal Aviation Administration (FAA), as well. 

Several of the airborne systems also relied on 

guidance or information from ground facilities, 

and all of the technology had to work in concert 
with air traffic controllers and other aircraft 

operating in the ATC environment. 

proved very difficult to implement or transfer to 

industry. Changing technology or procedures in 

the air traffic control system, where the penalties 

for errors or malfunctions could be disastrous, 

was a slow and complex process. And airlines 

would not buy the technology if the ATC system 

could not support its use. Nonetheless, some of 

the concepts developed and tested with the 

NASA 737 Transport Systems Research Vehicle 

(TSRV) were adopted by manufacturers, and by 

the early 1990s, the FAA was working on 

updated air traffic control equipment that could 

support more advanced and efficient airborne 

technology. 

As a result, some of these technologies 

Profile Descents 

As fuel prices rose in the late 1970s, airlines 

became increasingly concerned with improving 

the efficiency of their operations. Jet engines 

were designed to operate best at high cruising 

descent portion of the system allowed pilots to 

descend at their discretion, so they could plan a 

more fuel-conservative descent profile to the 

metering fix using an idle thrust, clean (flaps and 

speed brakes retracted) configuration. 

The LFM/PD system was first installed on 

an experimental basis at the Denver, Colorado, 

and Dallas-Fort Worth, Texas Air Route Traffic 

Control Centers (ARTCC). The system was a 

vast improvement over existing arrival 

procedures, but it still had a couple of significant 

drawbacks. The computerized program gave the 

controllers the time each aircraft was to cross its 

metering fix, but the controllers had to manually 

compute how to get the airplanes to that fix at 

the correct time, speed, and altitude. The pilots 

were given the speed and altitude, or altitude 

range, at which they were to cross the fix, but 

controllers had full responsibility for moditjring 

the cruise speed and/or descent profiles of 

arriving aircraft to meet the time requirements of 

the schedule. Using various manual calculations, 

controllers managed to achieve metering fix 

arrival accuracies as good as plus or minus two 

altitudes, and they ate up fuel very quickly in the 

denser air close to the ground. Consequently, the 

profits from a flight could evaporate quickly if an 

airliner had to spend a lot of time maneuvering 

at low altitude as it approached its destination. 

Unfortunately, the growing congestion around 

minutes. To do that, however, profile descents 

were often interrupted and aircraft speeds usually 

had to be modified. Consequently, there was still 

a significant gap between the fuel efficiencies 

obtained through LFM/PD and an optimum 

fuel-efficient flight and descent profile.’ 

many commercial airports meant that airline 

flights were often vectored around other air 

traffic or put into holding patterns as they 

neared the terminal area, wasting significant 

amounts of fuel. 

In an effort to improve this situation, the 

FAA began testing a new system called Local 

Flow Management/Profile Descent (LFM/PD) 

in the late 1970s. Local Flow Management was 

designed to reduce the need for low altitude 

vectoring or holding patterns by matching the 

arrival rate of all the airplanes coming to an 

airport to the num her and frequency of arrivals 

the airport could accept.’ LFM sequenced 

arrivals through one of four metering fixes 30-40 

nautical miles from the airport, at a specific time 

and in an order that would allow the airplanes to 

fly directly to the airport and land. The profile 

Airborne Trailblazer 

In an effort to close that gap, researchers at 

the Boeing Commercial Airplane Company and 

the NASA Langley Research Center in the late 

1970s began working on profile descent 

equations, using the four-dimensional, or “4-D,” 

capabilities of the TSRV 737’s flight 

management system (FMS). Two-dimensional 

navigation only managed an airplane’s horizontal 

path. Three-dimensional navigation controlled 

the aircraft’s vertical flight path as well as its 

horizontal direction, and four-dimensional 

navigation included a time element, as well. In a 

4-D navigational mode, the airplane would not 

only hold to a specific horizontal and vertical 

path, but it would also speed up or slow down to 

hold to a specific route or arrival time. The 

controller could simply give the pilot an 

altitude, speed and time to cross a metering 
fix, the pilot would enter those parameters 

into the flight computer, and the computer 

would calculate the most fuel-efficient flight 

path to follow to arrive at the fix as instructed 

by the controller. 

The software to give the 737 flight 

management system 4-D navigation capability 

was developed and tested first on a fast time 

computer and then incorporated into the TSRV 

real-time, piloted simulator. But the true test of 

the concept was whether or not it would be 

acceptable to pilots and controllers in a realistic 

ATC environment. So the sohare was installed 

in the TSRV 737 for a series of flight tests in the 

Denver LFM/PD system. Denver was chosen 

because it was the FAA’s lead center on the 

LFM/PD concept and had been given a certain 

amount of leeway to make minor changes to the 

ATC software as necessary to improve its 

operation. 

The plan was for the air traffic controllers to 

assign a metering fix time to the 737, and both 

the NASA researchers and the ground personnel 

would monitor how accurately the airplane met 

the fur time and how well the profile descents 

used by the 737 mixed with other air traffic in 

the area. The NASA researchers initially 

expected only a basic level of cooperation from 

the FAA, but the Denver ARTCC personnel 

contributed so much assistance in planning and 

conducting the flights that they became, in 

essence, a third partner in the research effort. In 

fact, the cooperation and involvement of the 

Denver ARTCC was a critical element in the 

success of the flight tests. 

The research flights took place June 19-28, 

1979. A total of 19 test runs were made from a 

cruise altitude to one of the metering fixes for 

Denver Stapleton airport. At approximately 110 

miles from the metering fix, the 737 crew was 

given a target arrival time, which was 

programmed into the flight computer. From the 

top of descent point to the metering fix, the pilot 

flew the airplane at idle thrust and without speed 

brakes, following computer-generated path and 

speed cues on the electronic flight displays in the 

737’s aft cockpit. Once the airplane crossed the 

metering fix, it broke off the approach and 

circled around to begin another test run. The 

flying duties were divided among two NASA 

pilots and four airline pilots, and each flight 

carried numerous FAA and industry observers, 

as well. 

There were a few initial compatibility 

problems, such as the fact that the initial 

metering fur times assigned by the LFM system 

required airspeeds slower than the 737 was 

physically capable of flying, but a few sohare 

changes corrected the difficulties. After that, the 

flight tests proved extremely successful. The 737 

was able to make the metering fix arrival times 

with a mean time error of only 6.6 seconds, 

altitude error of 33.6 feet, and airspeed error of 

.3 knots. In comparing the FMS-computed 

profile descent flight paths with conventional 

LFM/PD approaches used by airline pilots at 

Denver, NASA engineers found that pilots 

without the advantage of the precise guidance 

provided by the FMS tended to descend earlier, 

to ensure their arrival at the metering fix at the 

correct altitude and airspeed. The arrival time 

between the two differed only slightly, but 

the FMS-controlled profile descent used 28% 

less fuel.’ 

Assessments of the NASA profile descent 

flight tests from FAA observers were very 

positive, as well. Their evaluations included 

comments such as “Fantastic accuracy at 

metering fix and landing time. Will definitely 

reduce controller work load, save file1 and mi.ich 

frustration on part of the controller and the 

pilot,” and “Has potential for real capacity 

improvements.” The FAA observers also noted, 

however, that although NASA‘s single airplane 

had performed extremely well, there were 

additional issues that widespread use of airbornecontrolled profile descents would raise. What 

would be the consequences, for example, of 

different airplanes using specific, but different, 

climb and descent paths and speed profiles while 

still making their metering fix times? How 

would aircraft using profile descents mix with 

aircraft not equipped for that kind of approach? 

Would airspace have to be redesigned to ensure 

the safety of the procedure? In addition, 

although the airborne system had proved itself 
capable of accuracies within seven seconds, the 

ground metering system at that time was only 

accurate within 30 seconds, so the system in 

practice could not operate as efficiently as it had 

in the test flights4 

The questions raised by the FAA were all 

valid and important issues. They also 

underscored the particularly wide gap between 

the research and operational environments with 

technology designed to improve not just one 

aircraft component, but an entire nationwide 

system. Furthermore, the profile descents tested 

in the TSRV 737 depended on an onboard flight 

management system, which, with the exception 

of a few Lockheed L-101 Is, did not yet exist on 

any production airplanes. The Boeing 767 was 

the first new production airplane to include an 

FMS as standard equipment, and the first 767 

did not go into service until three years after the 

Denver profile descent flight tests were 

completed.' 

In an effort to resolve some of the issues 

surrounding the mix of aircraft with and without 

flight management systems, the Langley 

researchers conducted some additional profile 

descent experiments in 1984-85. Engineers used 

a hand held calculator to compute the necessary 

information for a profile descent on a T-33 

Sabreliner jet and several United Airlines jet 

transports. Preliminary results showed the pilot 

workload was acceptable, but analysis showed 

the pilot had to fly the faster portion of the 

descent very precisely, which was difficult 

without a flight management system. In 

addition, the calculators needed to perform the 

computations cost around $400 each, and pilots 

would have to be trained in their use, creating 

additional costs for the airlines.'' 

Even if all the airliners used either an FMS 

or a hand held calculator, however, the issue of 

ensuring safety in a system where individual 

airplanes were controlling their own descent 

paths would remain. The controllers would be 

unable to predict the exact trajectory of the 

descending airplanes, and there was too much 

potential for unexpected maneuvers. In one 

example related to a Langley researcher by the 

FAA ARTCC staff at Denver, a pilot was asked 

if he could make a certain arrival time at the 

metering fix. He replied he could, and then 

proceeded to start a 360 degree turn, back into 

conflicting traffic, in order to delay his arrival 

until the correct time.- 

The bottom line was that although the 

technology itself worked well, the ATC 

infrastructure was not equipped to incorporate it 

while still ensuring safe separation of air traffic. 

Even so, the United Airlines representatives who 

observed the test flights were impressed enough 

with the technology that they asked Boeing to 

look at the feasibility of incorporating 4-D 

capability into the flight management systems of 

the 767s they had on order. At that time, 

however, Boeing and its subcontractors had their 

hands full just developing a 3-D flight 

management system in time to meet the 767 

production deadline, so a 4-D capability was out 

of the question.' 

As flight management systems became more 

sophisticated, Boeing did start to incorporate a 

type of 4-D navigation capability into some of 

its airplanes. The Smith Industries flight 

management systems in the 737-300, 737-400, 

and 737-500 had the ability to compute 4-D 

flight paths. By 1933, Boeing was also planning 

to offer a kind of 4-D navigation, which it called 

Required Time ofArrival (RTA), for its 767 and 

747-400 aircraft as part of a suite of advanced 

navigation and communication functions." 

Yet even in 1993, although Local Flow 

Management was in widespread use, the ATC 

infrastructure was still incapable of integrating 

full 4-D navigation. The FAA was finally 

developing a more automated system that would 

allow more advanced navigation and 

communication, however. The new technology, 

called the Center Tracon Automation System 

(CTAS), was a concept originally developed by a 

researcher named Heinz Erzberger at the NASA 

Ames Research Center. Unlike the profile 

descent concept tested by Langley and Roeing in 

1979, CTAS was a ground-based system, but it 

gave the co tit ro I I cr t h c' sa me bas ic i n fi) rma ti o n 

the NASA pilots had derived from the airborne 

flight management system. Instead of just giving 

the controller a metering fix arrival time for each 

92 Airborne 7 i.dAzzer 
aircraft, the system also calculated an optimum, 

fuel-efficient descent path for each airplane that 

would not conflict with any other known traffic, 

based on current weather conditions and a 

database on each aircraft type’s performance 

figures. The controller could then radio 

instructions for that descent profile to the pilot. 

The system achieved the same basic end as the 4- 

D profile descents tested by NASA’s 737 in 

1979, but through a ground-based system that 

required no airborne equipment and took other 

traffic into account, as well.” 

In the fall of 1992, the TSRV 737 was again 

flown out to Denver to conduct preliminary tests 

using the CTAS concept. The flight tests 

produced arrival time accuracies within 11 

seconds, although the results indicated that the 

wind modelling component of the system 

needed improvement. The FAA planned to 

implement CTAS at Denver and Dallas-Fort 

Worth by 1996 and then install it at 12 major 

airports across the United States.” 

The profile descent concept tested with 

Langley’s 737, which relied on a 4-D navigation 

capability in an airborne FMS to design and 

execute fuel-efficient profile descents, was never 

implemented. It was a good idea, but ahead of its 

time and perhaps untenable in the complex ATC 

system. Nevertheless, the research did eventually 

have an impact. The 737 experiments proved 

the potential fuel savings that could be gained 

from 4-D navigation and precision profile 

descents, lending support to the inclusion of 4-D 

navigation in some later model transport aircrafi 

and to the eventual acceptance of the CTAS 

concept. 

Cockpit Displayed Traffic Information (CDTI) 

Soon after the profile descent experiments 

were completed in 1979, Langley researchers 

began work on another concept aimed at 

improving the efficiency of ATC system 

operations by giving pilots better navigation 

information and capabilities in the cockpit. The 

idea was Cockpit Displayed Traffic Information 

(CDTI), and the researchers in the TCV/ 

ATOPS program were interested in it because 

they saw it as “an important step in the direction 

of ‘electronic VFR (visual flight rules).” If pilots 

could “see” the other trafic in the area, it might 

allow reduced separation between aircraft, which 

would increase the efficiency and capacity of 

terminal operations.” 

about potential conflicting traffic had been 

around since the mid- 1940s, when researchers 

suggested that the new television and radar 

technologies might be combined to create a 

cockpit traffic display.” That idea never 

materialized, but in the early 1970s the 

Massachusetts Institute of Technology (MIT) 

received FAA sponsorship to conduct 

preliminary simulation studies of a more 

advanced cockpit display of traffic information. 

The MIT research indicated that the basic 

concept, at least, was well accepted by pilots.’* 

Researchers in NASA’s TCV/ATOPS program 

built on the MIT studies for a series of flight 

experiments in 1979 that tested both the basic 

CDTI concept and potential symbology for such 

a display, using the TSRV 737. 

The CDTI flight tests, conducted in the fall 

of 1979, consisted of a total of 29 curved, 

decelerating approaches into the NASA Wallops 

Island Flight Facility in Virginia. The research 

pilots had to execute the approaches while they 

monitored the traffic situation and reacted to 

potential conflicts. The traffic displays were 

created by integrating traffic information into 

the electronic horizontal situation indicators 

(EHSI), or map displays, in the aft research 

cockpit. Since the focus of the NASA 

experiments was on the pilot’s interface with a 

traffic display, the research flights used a prerecorded data tape of simulated traffic to create 

the images on the cockpit display. The tapes 

presented a realistic scenario of numerous 

airplanes following different flightpaths into the 

Wallops Island airport, however. The tapes 

could also provide the research pilots with 

scenarios in which the other pilots made 

mistakes in addition to normal, error-free 

situations. 

“course-up” display, with two-thirds of the 

The idea of giving pilots better information 

The format tested in the experiments was a 
94 

viewing area in front of the symbol representing 

the pilot’s own airplane. The position of the 737 

was updated almost continuously, while the 

other simulated traffic was updated every four 

seconds to replicate the speed with which an 

ATC radar could complete a sweep and update a 

display. The pilots could choose six different 

scales for the display, ranging from one to 32 

miles, and could set the display to show or 

suppress data blocks with more detailed 

information about each airplane symbol on 

the screen. 

The research flights also tested both “coded” 

and “uncoded” formats for the traffic symbology 

on the display. Both formats showed the past 

and current position of each aircraft and a trend 

vector indicating where it was headed, but the 

coded symbology also told pilots whether the 

traffic was above, at or below their own altitude, 

whether or not it was under ATC control, and if 

it had CDTI capability. 

The results of the flight tests indicated that 

the display improved pilots’ situation awareness 

and made them willing to use closer spacing with 

other aircraft during approaches. The pilots liked 

the coded symbology, although they indicated 

that they did not need to know whether other 

aircraft were CDTI equipped or under ATC 

control. There were some problems with use of 

the display, however. The EHSI could get 

extremely cluttered, especially if the data blocks 

on each airplane were displayed. The researchers 

also found that pilots had a tendency to fixate on 

the display, which could cause problems in an 

operational flight environment, where pilots 

needed to maintain an effective scan of the 

instrument panel and the airspace outside the 

aircraft. 

In addition, the tests showed that the raw 

display data was not really adequate for use in 

approach sequencing. It was difficult to detect if 

an airplane ahead was slowing down until so 

much of the gap had closed that the pilot 

following the CDTI had to reduce speed sharply 

to maintain adequate spacing. The rcsearchers 

also saw that trying to maintain the same spacing 

throughout an approach did not work, because 

all the airplanes stretched out along the approach 

Airborne Trtilbhzer 

path would have to slow down at the same time 

and to the same speed as the one closest to the 

airport to maintain the same spacing. That 

meant that airplanes would be slowing down to 

final approach speeds many miles from the 

airport.” 

Langley engineers conducted some follow-on 

simulator studies to research enhanced display 

formats that would allow a CDTI to be used for 

more efficient sequencing. NASA managers 

finally decided, however, that concepts such as 

4-D navigation could accomplish the same end 

as the CDTI technology with less difficulty. As a 

result, the CDTI technology was not pursued. 

The Traffic Alert Collision Avoidance System 

(TCAS) cockpit display the FAA later mandated 

for airliners did incorporate data on the location 

of potentially conflicting traffic, but the purpose 

of the information was for collision avoidance 

only, not for approach sequencing.“’ 

Data Link 

The data link research conducted by the 

ATOPS program was an effort to improve 

another aspect of ATC system operations. In 

addition to causing traffic delays, the growing 

congestion in terminal airspace was creating a 

radio frequency overload problem. So many 

pilots were trying to talk to controllers on the 

same frequency that it was often difficult for a 

pilot to squeeze in a transmission or request. In 

addition, the rapid pace at which controllers had 

to read off clearances and instructions in busy 

situations often led to miscommunications, 

errors, and the need to repeat transmissions. One 

possible solution the ATOPS program 

researchers saw for these problems was a two-way 

data link system. 

A data link system would allow messages 

between pilots and controllers to be displayed on 

CRT screens in the cockpit and at the 

controller’s station. The messages could be read 

and reread as necessary and stored for future 

reference. As a result, the system might be able 

to reduce not only the congestion ofATC 

frequencies, but also the number of 

miscommunications and errors and the need for 
repeated transmissions.” With the use of a 

satellite network, a data link could also allow 

pilots to communicate with controllers from 

remote locations, such as over the Pacific Ocean. 

In addition, data link offered the possibility of 

enhanced capabilities, such as displaying realtime weather reports and charts in the cockpit 

and direct communication between the 

airplane’s flight computer and computers on the 

ground. 

Engineers at the Langley Research Center 

began investigating the use of a two-way data 

link system for ATC communications in the 

early 1980s. Researchers working on a Single 

Pilot IFR (SPIFR) project conducted a flight test 

in a light twin engine airplane to evaluate 

whether a data link system would make ATC 

communications easier for pilots of small 

airplanes flying under instrument flight rules 

(IFR). During the SPIFR flight test, a pseudocontroller in the back of the airplane composed 

ATC messages for the pilot, which were then 

sent to the front of the plane and displayed on a 

screen in the cockpit.’* 

The flight test was followed by a series of 

real-time, piloted simulation studies that 

examined the use of various levels of data link 

capability in single pilot IFR flight operations. 

The simulation research showed that the data 

link system and cockpit display designed by the 

Langley engineers did, in fact, lessen the 

demands on the pilots’ short term memory and 

reduce the number of transmissions needed 

between the pilots and air traffic controllers. The 

results also indicated that a data link system 

made it easier for the pilot to allocate time to 

critical cockpit tasks while receiving ATC 

messages.” Encouraged by the positive response 

they got from the single pilot flight and 

simulation studies, researchers began to look at 

data link technology for ATC communications 

in jet transports. 

A commercial VHF data link system, called 

the ARINC Communications Addressing and 

Reporting System (ACARS) was already in use 

by the airlines. It allowed airline dispatchers to 

relay company messages, weather, and flight plan 

information to pilots. By 1989, Canadian air 

traffic controllers were also using an ACARS 

data link to transmit oceanic clearances to 

cockpit printers in aircraft preparing to cross the 

Atlantic Ocean, although pilots had to read back 

the clearances aloud over a conventional radio 

frequency. In 199 1, the FAA began to provide 

pre-departure clearances via an ACARS data link 

to airliners while they were still parked at airport 

gates.” Using a two-way data link as the primary 

communication mode for tactical and strategic 

ATC information, however, would be a much 

more dramatic change from conventional 

procedures. 

transport pilots consisted of a real-time 

simulation study that compared voice 

communications with data link messages for 

ATC communications and pre-recorded ATIS 

(Automatic Terminal Information Service) 

reports. The results indicated that pilots liked 

using a data link system for routine ATC 

communications, although they still preferred 

voice communications for urgent messages. 

Many of the test subjects also voiced some 

concern about the amount of “head-down” time 

required for reading and typing data link 

messages and the possibility of losing the 

situation awareness they obtained from listening 

to the communications between controllers and 

other pilots in the vicinity.” 

concerns, the Langley researchers began another 

simulation study in 1990 that incorporated 

several additional features. In addition to the 

written messages printed on the CRT screen, the 

study used a digitized voice to annunciate data 

linked ATC messages to the flight crew. 

Preliminary results indicated that the addition of 

the digitized voice made the two-way data link 

system much more acceptable to pilots.” 

Although the simulation results were 

promising, researchers felt it was also important 

to test the data link concept in a realistic ATC 

flight environment. Flight tests could validate 

the simulation results and point out potential 

operational problems with the technology that 

might not show up under simulated conditions. 

In addition, the ATOPS researchers had learned 

The initial NASA data link experiment with 

In order to explore possible solutions to these 
Data link displays 

with touch screen 

communication used 

to enhance traffic 

management around 

airports. 

Lej-A typical ATC 

message. 

Center-Pilot touches 

roger button to 

acknowledge. 

Rigbt-Pilot touches 

speed button to formuhte 

a speed change request. 

96 

that in the cost and risk-conscious world of 

airline operations, flying a new transport 

technology in an actual transport class airplane 

was often an important step toward winning 

acceptance for the concept among 

manufacturers, airlines and the FAA. 

The main question the flight experiments 

were designed to answer was not whether the 

data link technology would work, but whether 

the system would be acceptable to pilots. 

Consequently, one of the most important 

features of the experimental equipment was the 

cockpit display the pilots would use to interact 

with the system. The data link information was 

displayed on a CRT screen, and the Langley 

engineers designed the display format to be as 

easy to use as possible. The screen was covered 

with a clear, touch-sensitive panel that allowed 

pilots to select choices simply by touching the 

appropriate place on the display screen, instead 

of having to use a separate alphanumeric key 

pad. The display also used a “windows” format 

similar to the type used in many personal 

computers, with three different layers. 

The top layer, or window, was the smallest 

and always had visual priority over the other 

windows. It was used to display information sent 

from the ground to the airplane. The middle 

window was for the crew to compose messages to 

send to the ground, and the bottom, largest layer 

displayed the main menu page and the weather 

menu page. The top layer displayed was always 

the active window and had a white border and 

white print, while the inactive windows had blue 

Airborne TtaiLbhzr 

colored windows and print. Each window had 

touch-sensitive areas that were drawn as buttons. 

The pilots would touch the button areas to make 

choices, scroll through a message, or select 

different menus or information. When the pilot 

touched the screen, magenta touch-target lines 

centered on the selection the computer thought 

the pilot was making would appear, and the 

button would turn from white to green. After the 

pilot lifted his finger, the button would then flash 

twice to indicate the command had been accepted. 

The main menu contained six basic options, 

labelled ATC, Weather Menu, ATIS, NASA 

Ground, View Clearance, and View Messages. 

The bottom portion of the main menu was used 

to notify the pilots if they had non-time-critical 

messages from the ground waiting to be viewed. 

When the pilot touched a message waiting 

button, the message would be displayed in a 

small window. When the pilot had responded to 

the message, it would disappear. By touching the 

“Weather Menu” button, the pilots could access 

a wide variety of data linked weather 

information. Touching the “ATC” or “NASA 

Ground” button opened up the middle layer 

window, so the pilots could compose messages to 

data link to ATC or NASA facilities on the 

ground. The ATIS (Automatic Terminal 

Information Service) button opened up a menu 

that allowed the pilots to choose and receive the 

most current recorded weather, runway and 

other operational information for different 

airports. Selecting the “View Clearance” or 

“View Messages” buttons would present the 
pilots with a printed record of the clearances or 

messages transmitted and received during the 

flight to that point. 

If the pilot selected the ATC button, a 

second menu would appear with buttons for 

selecting various categories of ATC requests, 

such as “speed,” “heading,” “route 

modification,” etc., each of which also read the 

current clearance or value. If the speed button 

read 250, for example, the pilot could touch the 

button, and a new window would open up with 

a heading that read “NASA 5 15 requests: Speed 

250,” and two scroll buttons, one with an up 

arrow and the other with a down arrow. By 

pushing the appropriate scroll button, the speed 

value would increase or decrease. When the 

desired number was reached, the pilot would 

touch an “OK button in the lower right corner 

of the screen, and the display would return to 

the ATC menu page, with the new speed request 

printed at the top. The pilots could repeat this 

procedure for as many other request categories as 

they desired. To compose a route modification 

or a non-standard ATC request, the pilots could 

select a “compose” button on the ATC menu 

and type in whatever message they wanted, using 

the alphanumeric keys on the Control Display 

Unit (CDU) of the flight management system. 

When the message or request was complete, the 

pilot could touch a “Send” button on the main 

ATC menu page, and the message would be data 

linked down to a controller on the ground. 

If a time-critical ATC message was received 

at any point, however, it would be displayed on 

top of whatever window was currently in use, 

and a digitized voice would repeat the message 

aloud to the crew. The flight crew had to 

respond to any time-critical messages before any 

other message could be composed or received. 

The flight crew had three possible options for 

responding to a time-critical ATC message. They 

could select a button that said “Unable,” if they 

could not comply with the ATC instructions, or 

they could touch a “Roger” button to simply 

acknowledge the message and communicate their 

intention to follow the instructions. The third 

option was to select a “RogedEnter” button. By 

touching that button, not only would a “Roger” 

message be data linked down to ATC personnel, 

but the ATC instructions would be 

automatically entered into the flight 

management system. With the touch of a single 

button, therefore, ATC-requested changes in 

routing, altitude, speed or heading could be 

acknowledged, accepted, and executed. 

consisted of a phone modem link to a digital, 

real time weather data base, a data link processor, 

two separate VHF data link sources that 

communicated with data link receiver/ 

transmitters on the airplane, and numerous voice 

frequencies. Since the point of the flight tests 

was to evaluate pilots’ acceptance of a data link 

system for ATC communications, the flights 

were conducted in the vicinity of the Wallops 

Flight Facility, where actual communications 

with ATC were not required. For most of the 

flight tests, NASA researchers on the ground 

acted as air traffic controllers, composing 

instructions, clearances and route modifications 

to send to the flight crew. When weather 

conditions forced the crew to fly under actual 

instrument conditions one day, the research 

pilots were still able to use the data link system. 

Messages between the pilots and the FAA 

controllers were simply relayed through 

researchers in the NASA ground station, who 

data linked the controllers’ instructions to the 

research crew and verbally relayed the crew’s data 

linked responses and requests to the controllers. 

The NASA researchers wanted to evaluate 

how operational flight crews would accept the 

The ground equipment for the experiments 
use of a data link system, so they selected pilots 

from five different commercial airline companies 

to fly the research flights. A total of seven twoperson crews were chosen and given one day of 

orientation in the TSRV 737 simulator before 

flying the data link experiments. Because the 

training was limited to one day, the researchers 

selected pilots who had previous experience 

using electronic flight displays and flight 

management systems. Each crew flew three 

different 250 mile circle routes that each 

included a takeoff, climb, cruise, descent, and 

approach to landing, so the flights could 

incorporate a range of typical airline/ATC 

communications. Each flight also included at 

least one route modification. In one of the 

circuits, the pilots used only voice 

communications with the ground controllers in 

order to establish a baseline against which the 

data link performance could be measured. The 

second and third circuits used data link as the 

primary communication source. Clearances for 

taxi, takeoff and landings, however, were always 

made with voice communications. 

repeats each crew experienced were tracked 

during the flights, and the crews were all 

debriefed after their flights were completed. The 

results were striking. There were five instances of 

confusion with voice communication, and none 

using data link. The pilots had to ask for 

messages to be repeated 46 times with voice 

communication. Messages only had to be 

repeated 12 times during the flights relying 

primarily on data link, and all of those 

repetitions were during portions of the flight 

where voice communications were being used. 

While there were seven errors with both voice 

and data link communications, all but one of the 

errors on flights using data link involved tuning 

the voice communication radio to the incorrect 

frequency. In other words, the ability to read, 

store and re-read the data link messages 

effectively eliminated errors due to 

miscoi-nmunications and the need for the 

repetition of ATC messages. 

agreed that the use of data link reduced their 

The errors, miscommunications and message 

The airline pilots conducting the flights 

workload and allowed them to distribute it 

better, especially if ATC commands could be 

acknowledged and put into the flight 

management computer with the touch of a single 

button. Six of the seven crews also thought that 

data link would make an acceptable primary 

ATC communication medium for most flight 

segments, as long as voice communication was 

available as a back-up. However, the crews all 

thought that communications in terminal areas 

should still be conducted primarily through 

voice radio to reduce the amount of “headdown” time in busy traffic areas. They also 

suggested that at least the time-critical ATC 

messages should be displayed in the pilot’s 

forward field of view.” 

The NASA experiments were the first flight 

tests using data link as a primary source for ATC 

communications. But the airlines already had a 

strong interest in the technology and were eager 

to get Langley’s test results, The research flights 

using airline pilots were completed in early May 

1990. Before a month had gone by, the human 

factorsldata link group of the Air Transport 

Association had asked for a flight demonstration 

of the technology. Typical attendance for the 

group meetings was reportedly about 15 people, 

but 60 airline representatives showed up at 

Langley to see the data link system in operation.’‘ 

The Langley engineers also realized from the 

start that a data link system would require the 

support and involvement of the FAA as well as 

the airlines and airframe manufacturers. So 

although the flight tests did not evaluate the 

impact of data link on controller workload or 

ATC system safety, the researchers took several 

outside observers along on the flights, including 

an air traffic controller from the ATC data link 

design group. The controller’s response to the 

data link system tested by Langley was extremely 

positive, and he thought that controllers would 

like to use data link for ATC airborne 

information with the cxccption of landing 

clearances. ” 

The FAA and the airlines were both 

interested in data link because they believed it 

could enable more efficient air traffic operations. 

The airlines, for example, saw data link as a way 

Airhome fidhkzzzr 
to enhance the efficiency of transoceanic flights. 

With only VHF and High Frequency (HF) radio 

communications, it was difficult for flights to 

maintain contact with ATC or the airline 

dispatchers far from shore. Consequently, it was 

difficult for flight paths to be changed en route, 

even if the pilots encountered different winds 

than were predicted. With a data link system, 

airline dispatchers could send updated wind 

information to their pilots via satellite, and the 

pilots could compute a more efficient flight path. 

The pilots could then send a re-routing request 

via satellite to a ground station in the U. S., and 

then through a VHF data link to air traffic 

controllers. If data link were combined with a 

global positioning system (GPS), the position of 

airplanes could be automatically sent to the 

oceanic ATC controllers so that they could view 

all the airplanes in their area as if they had radar. 

Armed with this information, controllers could 

allow more direct routing and closer spacing. 

Based on some preliminary trials, a data link 

system was estimated to have the potential of 

saving between 3,000 - 6,000 Ibs. of fuel and 

eight minutes of flight time on a flight between 

Los Angeles, California, and Sydney, Australia.” 

The FAA saw the use of data link primarily 

as a way of reducing frequency congestion and 

controller workload. However, a data link system 

might allow future enhancements to the planned 

CTAS procedures. Specifically, a VHF data link 

would enable the CTAS computer and each 

airplane’s flight management computer to 

communicate directly. As a result, the computers 

could actually negotiate a safe descent profile 

optimized not only for that general type of 

aircraft, but for that particular airplane, taking 

into account its fuel, weight, and system 

performan~e.~’ 

In 1993, FAA plans called for an ATC data 

link system for transoceanic flights by 1995 or 

1996, with data link capability at key domestic 

en route, terminal and tower locations by late 

1996. Although some questions still remained 

about what transmission format the data link 

system should use, the most likely option 

appeared to be a composite structure that used 

VHF frequencies, Mode S discrete code 

transponders and satellite links.’8 

technology, data link did not have to be sold to 

the airlines. They wanted it as soon as possible 

and were even “pushing the FAA harder than the 

FAA could accommodate developing and 

implementing it.”” As a result, manufacturers 

began incorporating data link capability in many 

new transport airplanes. Boeing, for example, 

included two-way data link in an updated suite 

of navigation and communication functions 

available for new or existing 747-400s and new 

production 767s. The company also planned to 

include two-way ATC data link capability in its 

new B-777 airplane.’” 

Data link technology clearly had potential 

for making flight operations in the ATC system 

more efficient. An equally important factor in 

the rapid transfer and acceptance of the research 

information by industry, however, was the 

timing of the Langley experiments. The NASA 

data link flights were done at a time when the 

airlines were already pushing the FAA to develop 

a data link capability for ATC communications. 

The successful flight tests lent the concept the 

exact kind of support and credibility the airlines 

were seeking, which is why they jumped at the 

technology so quickly. At the same time, the 

NASA research flights provided the FAA with a 

measure of confidence in the ability of a data 

link system to handle ATC communications as 

well as the acceptability of such a system to the 

pilots who would have to use it. 

As opposed to many kinds of new 

Precision Flare Laws 

From the start, the researchers working on 

the TCV program believed that an important 

element in increasing the capacity of existing 

airports was the development of technology and 

procedures to allow less separation between 

aircraft. If airplanes could be spaced closer 

together, airports could handle a greater number 

of takeoffs and landings in any given time 

period. Closer aircraft spacing, however, required 

not only improved cockpit equipment and ATC 

communications, but more efficient landing and 

taxi operations, as well. Regardless of how 
efficient flight operations were, aircraft could not 

be spaced less than two minutes apart if it still 

took two minutes for an airplane to land, slow 

down, and taxi off the runway. 

In an effort to allow aircraft to taxi off 

runways sooner, many airports were equipped 

with high-speed runway turnoffs by the late 

1970s. The turnoffs were vastly underutilized, 

however, especially in low visibility conditions.” 

To make the most efficient use of the turnoffs, 

pilots had to plan their touchdowns for a point 

on the runway that would allow just enough 

time for the airplane to slow down to a safe 

speed before reaching one of the high-speed 

exits. Aircraft autoland systems only had to 

achieve a touchdown accuracy within 1500 feet 

in order to receive FAA certification, however.” 

This meant that airplanes took longer to touch 

down and often missed turnoffs, spending a 

greater amount of time on the runway. 

Engineers at the Langley Research Center and 

the Boeing Commercial Airplane Company 

reasoned that if autoland systems could be made 

more precise, they could plan the touchdown 

spot of airplanes to allow them to get off 

runways more quickly, increasing the potential 

capacity of airports. More precise autoland 

systems would also reduce the operational field 

length requirements for aircraft, opening up 

more airports as potential landing sites. 

such wide dispersion rates was the control law 

that determined when the airplane began its 

landing flare. The most commonly used flare 

control law in the mid- 1970s used the aircraft’s 

altitude above the runway as the cue to begin the 

flare. The airplane’s sink rate would be steadily 

decreased as the airplane got closer to the 

ground, until it landed. The problem with this 

approach was that depending on the winds, the 

aircraft would cover dramatically different 

amounts of ground between a given altitude and 

the point where it touched down on the runway. 

With a 40 knot headwind, for example, the 

groundspeed of the airplane would be slower, so 

it might cover little ground in the last 50 feet of 

a descent. If there was a 10 knot tailwind, on the 

other hand, the airplane could float far down the 

The part of the autoland systems that caused 

runway before it touched down. 

and flight tested two possible improvements to 

this control law, using the TSRV 737 airplane. 

The first concept simply incorporated 

groundspeed as measured by the airplane’s 

inertial navigation system (INS) into the flare 

law algorithms so the aircraft’s sink rate would 

be arrested more quickly if the groundspeed was 

higher. The second approach was a more 

complex, but more precise, “path-in-space” flare 

trajectory law that aimed the aircraft toward a 

specific point on the runway. The path-in-space 

law essentially extended the glideslope all the 

way to landing and kept the airplane on the 

correct glideslope. The aircraft’s altitude, sink 

rate and vertical acceleration were all 

commanded as a function of the plane’s position 

along the runway. 

began in 1978, in conjunction with the 

microwave landing system (MLS) demonstration 

flights the NASA 737 was performing for the 

FAA. In 58 landings with the first “Variable 

Time Constant Flare” control law, all the 

touchdown points were within 641 feet, and 95 

percent of them were within 548 feet. The pathin-space concept was then tested with three 

different landing guidance systems: an ILS 

(Instrument Landing System), a basic MLS, and 

an MLS with a secondary flare elevation signal. 

Ninety-five percent of the landings that used the 

basic MLS signal for guidance touched down 

within a 592 foot distance. Using the MLS 

signal with the secondary flare elevation signal, 

that distance dropped to 368 feet, and all of the 

ILS-guided landings touched down within 285 

feet. Clearly, the new control laws could improve 

the performance of autoland systems far beyond 

the 1500 foot dispersion requirements set by the 

FAA. ” 

Nonetheless, convincing industry to adopt 

new flare control laws for the sole purpose of 

improving airport capacity would undoubtedly 

have been extremely difficult. More precise 

autoland systems would only increase capacity if 

every airplane was equipped with them, and then 

only if all the other separation issues could be 

The Boeing and NASA engineers researched 

The flight tests of the new control laws 

Airborne Trailbhm 
resolved, as well. The precision flare laws offered 

another, more financially compelling advantage 

to manufacturers, however. A path in space or 

variable time constant flare law could make it 

easier for a manufacturer to meet the 1500 foot 

accuracy required for autoland certification, 

which translated to cost savings in the 

certification process. The Boeing 7671757 

autoland system, for example, did not initially 

meet the FAA’s 1500 foot requirement. In order 

to pass the FAA requirements, the design 

engineers ended up developing a path-in-space 

flare law for the airplane that was later adopted 

for the 747 aircraft, as well, although the 

production control law used different algorithms 

than those developed by the Boeing/NASA 

research engineers. In addition, the variable time 

constant flare law was incorporated into the 

Boeing 737-300 model aircraft, although it had 

to be modified slightly because the 737-300s did 

not have INS eq~ipment.’~ 

The flare law experiments also showed the 

researchers at NASA once again that having a 

transport airplane with which they could actually 

flight test and demonstrate new technology 

concepts could be extremely valuable. One of the 

NASA engineers who worked on the flare law 

research remembered getting a phone call during 

the experiments from a colleague who told him 

that, for a variety of reasons, a path-in-space flare 

law could never work. “Why don’t you come 

down here next Tuesday and we’ll fly it for you,” 

the engineer replied, effectively ending the 

debate.” The fact that a path-in-space law had 

been successfully demonstrated on an airplane 

eliminated discussion about whether it was 

possible and substantially lowered the risk of 

incorporating it into a commercial airplane. The 

production engineers at Boeing merely had to 

decide how they wanted to design their own 

version. 

Magnetic Cable Guidance 

The underutilization of high-speed runway 

turnoffs in low visibility conditions was also due 

in part to the fact that pilots lacked the necessary 

guidance to help them find the exits and taxi 

safely off the runway. In an effort to overcome 

this obstacle, NASA researchers began 

investigating the possibility of using a buried 

magnetic cable to provide rollout, turnoff and 

taxi guidance for airplanes once they landed. 

A magnetic cable system consisted of an 

electrical cable buried in the center of the 

runway, turnoffs and taxiways of an airport. An 

audio-frequency current was sent through the 

cable, setting up a magnetic field. By measuring 

the strength of the field, on-board airplane 

sensors could indicate how far away from the 

cable the airplane was, and the aircraft autopilot 

could use that information to follow the cable 

along the runway, turnoffs, and taxiways. 

The idea of using a magnetic cable for 

aircraft guidance was first tested by the British in 

the 1950s and 1960s as a way to allow landing 

operations in extremely low visibility conditions. 

The British wanted to use the cable to provide 

guidance during an airplane’s final approach to 

the airport as well as steering guidance on the 

ground, however, which proved to be beyond 

the capabilities of the technology.’6 Although the 

British never implemented the cable guidance 

system, researchers working with the TCV 

program in the late 1970s resurrected the idea as 

a way to improve the efficiency of ground 

operations at airports in poor weather 

conditions. 

A couple of simulator studies evaluating the 

feasibility of a cable system for airplane ground 

navigation and guidance were conducted in the 

late 1970s and early 1980s at the Langley 

Research Center. The studies indicated that the 

idea might be both feasible and practical for 

commercial aircraft. At the same time, other 

researchers at Langley were working on possible 

designs for the cable system itself.” 

The system was initially tested using a 

temporary cable and a van-mounted sensor at 

the Wallops Island Flight Facility in a series of 

experiments from 1979-1984. Then in 1988, 

both static and taxi tests were conducted with 

the cable system and the TSRV 737 airplane at 

Wallops Island to gather additional information 

on the performance of different signal gains and 

frequencies. Researchers were concerned that the 
large amounts of metal in an airplane might 

interfere with the signals, but the tests indicated 

that although the metal interfered with the 

system's ability to give accurate heading 

information, it could still reliably indicate the 

airplane's distance from the cable. There were 

some electromagnetic interference (EMI) 

problems caused by the airplane's power system 

and VHF radio communications, but it appeared 

that use of filtering techniques could reduce the 

EM1 to an acceptable level.'R 

Using the data gathered in the 1988 tests, 

researchers fine-tuned the cable system and 

developed the necessary control laws to allow the 

737's autopilot to process and use the magnetic 

cable signals. The entire system was then 

evaluated in high-speed taxi tests at Wallops 

Island in 1991. The tests used a combination of 

the Wallops Island microwave landing system/ 

distance measuring equipment (MLS/DME) and 

the magnetic leader cable to provide the 

guidance the TSRV 737's autopilot. The results 

of the tests indicated that the cable system could 

work, but it needed further development to 

smooth its operation to an acceptable level. 

magnetic leader cable system were put on hold at 

that point, however, because another potential 

solution to the same problem had appeared on 

the technology horizon. As research progressed 

with the satellite-based global positioning system 

(GPS), it appeared that the system might be able 

to provide guidance on the ground as well as in 

the air. In the spring of 199 1, the TSRV 737 

began ground tests using GPS to guide the 

airplane through its rollout and turnoff from the 

runway. Obviously, if the same GPS receiver 

that airliners were using for airborne navigation 

could also be used for ground guidance in low 

visibility conditions, it would save the cost of 

installing and maintaining the extra ground and 

airborne equipment the magnetic cable system 

would require."' 

The research goal remained the same, 

however, even if the specific technology being 

evaluated had changed. In order to significantly 

reduce the amount of spacing between arriving 

aircraft, ground operations had to be made more 

Additional research and tests with the 

efficient, especially in poor weather. The 

magnetic cable leader system and GPS 

navigation both held potential for providing 

better ground navigation guidance to pilots, and 

the TSRV 737 made it possible for the NASA 

researchers to evaluate their performance not 

only in theoretical or simulated conditions, but 

with a transport class airplane in a realistic 

airport environment. 

Summary 

Developing technology to improve the 

operation of the national airspace system offered 

potentially significant payoffs, but it was a far 

more complex process than simply inventing a 

more efficient airplane component. Operationsoriented technology had to win the support of 

the FAA as well as the airlines and airframe 

manufacturers, and it had to be not only costeffective, but compatible with other air traffic 

and the ground-based infrastructure of the ATC 

system, as well. The 4-D profile descents 

researched by Langley engineers in the late 1970s 

worked extremely well on the 737 and showed 

potential for saving airlines significant amounts 

of money, but the ATC infrastructure could not 

support their use. The two-way data link 

research, on the other hand, received more 

support because the FAA was already planning 

infrastructure changes that could accommodate 

data link technology. 

was also a difficult task because many of the 

components were inter-related. Developing 

technology to allow decreased spacing between 

aircraft in flight would have no benefit if the 

airports could not accommodate more closely 

spaced arrivals. Precision flare laws could help 

autoland systems deliver airplanes to a more 

optimum point on a runway, but that would 

only help increase airport capacity if additional 

technology could be developed to help pilots 

find the runway turnoffs and taxiways in low 

visibility conditions. Gaining support for 

technology that would improve individual 

components, therefore, could be difficult unless 

it could also provide a stand-alone benefit for the 

Improving the operations of the ATC system 

I02 Airborne Trailbhzer 
airlines or manufacturers. Even without being 

implemented system-wide, for example, data link 

could help airlines save fuel costs on transoceanic 

flights. The precision flare laws made it easier for 

manufacturers to pass certification testing for 

aircraft, even if the rest of the elements needed to 

improve airport capacity in poor visibility 

conditions were not available. 

conducted by the TSRV 737 also played an 

The flight experiments and demonstrations 

important role in winning support for concepts 

like precision flare laws and data link 

communications. In addition to giving industry 

and the FAA valuable and convincing 

information about the performance of the 

technology in realistic flight conditions, 

successfully demonstrating concepts in a 

transport class airplane made it virtually 

impossible for anyone to argue that the 

technology would not work. 

Chapter 8 

A National Facility 

Le$- The LangLey 

737 ‘j7ying laboratory” 

in flght. 

Right- The helmet 

mounted disphy worn by 

research pilot Lee Person, 

being tested in 737 

aircraji. 

he NASA Transport Systems Research T Vehicle (TSRV) 737 was, without a doubt, 

a one-of-a-kind airplane. NASA had many other 

research aircraft, and the Federal Aviation 

Administration (FAA), the military, and the 

airframe manufacturers all had transport class 

test planes, but the NASA 737 possessed a 

unique combination of equipment and 

capabilities. In 

addition to having a 

complete second 

flight deck 

exclusively for 

research purposes, 

electronic flight 

displays, and a 

computerized fliEht - 

control system, the 

airplane had 

extremely precise 

instrumentation and 

data gathering 

capabilities. The 

onboard research computers could record up 

to 540 pieces of data from various locations on 

the airplane at any given time.’ Video 

equipment could record the screen displays in 

the aft cockpit as well as the view out the nose 

of the airplane. Since the research equipment 

and computers were installed in individual 

pallets in the back of the airplane, the airplane 

could be outfitted for different types of 

experiments fairly easily, and the large interior 

cabin of the 737 could accommodate up to 30 

researchers and observers. The equipment on 

the TSRV 737 also allowed it to fly complex 

flight paths and perform extremely accurate 

navigation. 

As a result, although NASA purchased the 

airplane specifically for the Terminal Configured 

Vehicle (TCV) program research, the airplane 

was also able to 

support a variety of 

other research projects 

over the years. Before 

the plane had been at 

the Langley Research 

Center a complete 

year, for example, the 

FAA requested its 

participation in the 

U.S. microwave 

landing system (MLS) 

demonstrations. 

Although the work 

was not part of the 

original TCV program agenda, the MLS 

managers in the FAA realized that the 

computerization and electronic flight displays in 

the 737 made it capable of providing a much 

more dramatic and convincing demonstration of 

the U.S. system than any airplane the FAA had 

available. 

In the years that followed, the TSRV 737 

was also used to flight test experimental wing 

surface coatings, evaluate the effect of poor 
106 

weather conditions on runway surfaces and the 

ability of ground vehicles to measure those 

conditions accurately, and to gather data on air 

flow over fuselage and wing surfaces to help 

engineers improve the design of future transport 

aircraft. The McDonnell Douglas Corporation 

used the TSRV airplane to test a helmetmounted display concept the company was 

developing for the X-30 National Aerospace 

Plane. Because the 737 could fly such complex 

and precise flight paths, the Department of 

Defense used it to determine if flight operations 

at the new proposed airport in Denver, Colorado 

would interfere with national defense satellites. 

The FAA also enlisted its help to model the 

Instrument Landing System (ILS) signal at the 

Los Angeles International Airport. 

support aircraft for a specific research program 

into a national airborne research facility. 

Whether the customer was a research directorate 

at Langley, another government agency, or an 

industry manufacturer, the 737 provided a 

flexible, highly capable platform that could 

gather valuable research data and flight test a 

wide variety of aeronautical and aerospace 

concepts. 

In short, the TSRV 737 had evolved from a 

Wing Surface Coatings 

As fuel prices rose in the late 197Os, the air 

transport industry became increasingly interested 

in technology and procedures that could make 

airline operations more efficient. One area 

manufacturers focused on was airframe drag 

reduction, because even a small reduction in 

drag could have a tremendous impact on 

operating costs. A one percent drag reduction 

on a Boeing 727 airliner, for example, was 

estimated to save 20,000 gallons of fuel per year.' 

Preliminary experiments in the low 

turbulence wind tunnel at the Langley Research 

Center showed rhat smoothing a wing surface 

area by applying an adhesive film coating could 

reduce its drag by as much as 12%, which 

translated to a 2-3% reduction in the overall 

drag of the airplane.' In 1977, the Boeing 

Commercial Airplane Company began 

Airborne Trtlilbhzer 

investigating the potential of specific coating 

materials, running a total of 15 liquid coatings 

and 60 film adhesives through a series of 17 

laboratory tests to determine which of the 

different materials could best withstand the 

rigors of airline use. The materials were first 

evaluated for their resistance to erosion from rain 

or various aircraft fluids such as fuel, deicing 

solutions, or hydraulic fluid. Out of all the 

materials, four adhesive films and three liquid 

coatings proved the most resistant to erosion and 

were recommended for further testing. 

Since the adhesive films had a lower 

resistance level than the liquid coatings, however, 

they were not recommended for high-erosion 

areas of the airplane, such as the leading edges of 

the wings. The films showed potential for areas 

like the forward body of the airplane, but 

installing adhesive film on large, curved surfaces 

would have been an expensive and timeconsuming effort. As a result, the rest of the 

evaluations focused primarily on the liquid 

coating materials. 

The liquid coatings, which went by the 

names CAAPCO, Chemglaze, and Astrocoat, 

were run through another series of laboratory 

tests to further evaluate their resistance to 

erosion and their compatibility with aircraft 

systems. The CAAPCO and Chemglaze coatings 

were then applied to two operational airliners for 

flight service evaluation.' Continental Airlines 

applied the coatings to the wing and horizontal 

tail leading edges of a Bocing 727 and tested 

their resistance to erosion in two different 

environments. The aircraft was flown for 14 

months in the Air Micronesia route system, 

where an annual rainfall of over 90 inches and 

the fact that some airports used coral runways 

caused significant erosion problems with paint 

on aircraft leading edges. Continental then 

conducted a second, 1 I-month evaluation of the 

coatings with the same B-727 on domestic 

routes in the United States. Although the 

coatings suffered significant erosion in both 

cases, an outboard horizontal tail section with 

the coatings applied by Boeing Laboratory 

technicians was then installed on the 727 and 

flown for an additional 18 months, 
1 A Langlq technician 

work5 on the wing of the 

model Boeing 737 in the 

14 by 22foot subsonic 

wind tunnel. 

accumulating 3800 flight hours with almost no 

erosion of the coatings. The two coatings were 

also tested by Delta Airlines on a B-727 to 

evaluate the impact of different colors and 

primers on the effectiveness of the coatings. After 

16 months and 4348 flight hours, some coated 

areas had peeled or eroded, but others were still 

holding up fairly well. 

kind of liquid, elastomeric polyurethane coating 

could reduce aircraft drag. Since any reductions 

in drag were expected to be small, results from 

wind tunnel models or smaller aircraft would not 

necessarily apply to transport class airplanes. 

Consequently, drag measuring flight tests had to 

be conducted on a full-scale, transport class 

airplane that could record precise data through 

instrumentation on the surface of the wing. 

This was obviously beyond the capabilities of 

operational airliners, but the NASA TSRV 737 

was perfectly suited for the task. 

The test substances were applied to the 

upper inboard surface of the left wing and 

compared against the performance of the same 

section on the right wing, which was kept as a 

bare metal surface. The flight tests compared the 

performance of the CAAPCO substance against 

the Corogard corrosion-protective paint that was 

a popular aircraft surface coating at that time, as 

The next question was whether or not this 

~ ~~~~ - 

well as a gritty strip that was installed on the 

leading edge of the wing section to represent a 

coating that was somewhat eroded. The results 

showed that compared to the bare metal surface, 

the CAAPCO substance reduced the total drag 

of the airplane by about 2% in cruise 

conditions, whereas the Corogard coating 

increased aircraft drag by about the same 

amount. 

The Boeing and NASA experiments showed 

that the CAAPCO coating could be resistant to 

erosion and could reduce drag on the wing of an 

aircraft, but more research was needed to 

determine if a CAAPCO or Chemglaze 

substance would provide as much protection 

against corrosion as the coatings already in use. 

The coatings also might not be as effective in 

actual airline operations, because the quality of 

the application process clearly affected their 

lifespan and effectiveness. Although the 

laboratory coated wing tested by Continental 

held up extremely well, laboratory-quality work 

would be difficult, if not impossible, to achieve 

in a busy airline maintenance environment. But 

while there were issues that might affect the 

commercial use of the substances, the TSRV 737 

flight tests showed Boeing that elastomeric 

polyurethane coatings at least had the potential 

for reducing drag on transport aircrafi.’ 
LEBU/High Lift 

The TSRV 737’s precise data gathering 

capability also led it to be chosen for NASA 

research projects that were not within the 

original parameters of the TCV/ATOPS 

program. Two different flight experiments, for 

example, focused on measuring and analyzing air 

characteristics of the airflow over the airframe. 

Data was gathered throughout a range of speeds, 

attitudes and altitudes from 10,000 feet to 

25,000 feet and from Mach .5 to Mach .8.” 

A second set of flight experiments had been 

planned with LEBU devices installed on the 737 

airframe. Further ground testing of the LEBU 

concept indicated that it would not actually 

reduce drag in flight conditions, however, so the 

research was discontinued.- 

A second research project measured the air 

flow characteristics of the 737’s wing 

flow over sections of the aircraft wing and 

fuselage in an effort to help 

engineers design more 

efficient transport 

and flap system to help /--

~ , . ..11.“ 

I ..*.I*- - engineers create more 

7: 

Id 

LiingIey I<aecrrch Center 

wit/i.fl.r-, deployed 

during high-liji rcw/rrch. 

c-- aircraft was an 

important tool in research areas involving air 

flow and drag analysis, because some of the 

measurements were sensitive to “scale effects.” In 

other words, some of the flow characteristics 

observed on small wind tunnel models would 

not hold true for a full-scale aircraft in flight. 

The TSRV 737 allowed researchers to obtain 

accurate flight data that then could be used to 

update computer models and provide more 

accurate data to aircraft design engineers. 

the air flow around its fuselage as a first step 

toward evaluating the effectiveness of Large 

Eddy Break-Up (LEBU) devices. The LEBU 

concept involved mounting small airfoils on the 

airframe to help reduce skin friction drag. In 

order to determine the effect of the LEBU 

devices, however, researchers first had to have 

precise information about the standard airflows 

around a transport airframe. So the upper 

portion of the 737 fuselage was outfitted with 

nu me ro us data gat her i n g i n s t ru men ts i ncl ud i ng 

pressure belts, pitot rakes, hot wire rakes, hot 

films, and piezoelectric foil to measure the 

pressure, speed, flow, and turbulence 

In 1988, researchers used the 737 to measure 

efficient high-lift designs 

. 4 for future transport 

aircraft. The TSRV 737 had 

11 transport aircraft flap system, 

iple-slotted Fowler flap.” In 

. that extended from the front of 

craft had a three-part flap at the 

, that first slid back, and then 

down, when it was deployed. As the flap slid 

back and the slat slid forward, the area of the 

wing, and therefore the lift it could produce, 

increased. This was critical when the aircraft was 

flying slowly, such as on approach to landing or 

immediately after takeoff. 

When Airbus Industries came out with a 

simpler, single piece flap for its A-3 10 and A320 aircraft that had the same performance as 

the three-part design, however, NASA and the 

U.S. manufacturers realized that the European 

consortium had edged ahead of the U.S. in high 

lift technology. To try to correct this perceived 

lag in U.S. technology, NASA began a multiphased program in subsonic transport high-lift 

research.’ 

learn more about the flow characteristics of 

current transport high-lift systems. This data 

could then be used to create more ;icciirate nnd 

p rec isc ni ;i th ;I nd com p 11 t;i t io n a1 flu id dynamics 

models which, in turn, could bc used by 

engineers to design better systems. In order for 

the models to be accurate, however, the data had 

to be obtained from a full-scale transport aircraft 

The triple-slotted flap systcm worked well. 

One of the first steps in the program was to 
The Boeing 737 testbed 

during run way friction 

tests at Brunswick Naval 

Air Station, Maine, in 

1985. 

in actual flight conditions. Since the TSRV 737 

was already set up for extensive and precise data 

gathering and it was kept at the Langley 

Research Center, where the high-lift research was 

being conducted, it was the logical choice for the 

experiments. 

right wing and flap system were “tufted” with 

short pieces of string to help researchers visualize 

the basic air flow patterns across them in various 

flight configurations. In 199 1, a second set of 

flight tests was conducted with more elaborate 

instrumentation on the three elements of one 

right wing flap section. Pressure belts recorded 

the surface pressure distribution over the flap 

segments, and instruments called Preston tubes 

measured the skin friction levels at various 

locations on the flap surfaces. A third set of flight 

tests in February 1992 used the same 

instrumentation, but expanded the test area to a 

full-chord strip that started at the front of the 

leading edge slat and ran back across the wing to 

the trailing edge of the flap. Another set of 

flights with even more precise instrumentation, 

including infrared imaging systems, hot-film 

sensors and micro vortex generators, was 

scheduled for the end of 1993.’ 

The large gaps in between the flight tests 

were one of the main drawbacks to using the 

TSRV for flight experiments. So many research 

projects wanted flight time on the airplane that 

it was difficult to get a place on the schedule. 

Nevertheless, the data obtained from the 737 

For the initial flight tests in 1990, the 737’s 

flights was very useful to the on-going high-lift 

research at NASA. The flight test data 

corroborated some wind tunnel test results, 

corrected the predictions of others, and gave 

research engineers additional information about 

the dynamics of high-lift flow physics. That 

information could help manufacturers design 

more efficient aircraft and, at the same time, 

restore the United States’ competitive edge in 

the field of high-lift technology. 

Runway Friction 

In January 1982, two airline accidents within 

a matter of weeks suddenly focused national 

attention on the hazards of winter flying. On 

January 13, 1982, an Air Florida 737 crashed 

into the 14th Street Bridge after departing 

Washington National Airport, killing 78 people 

on board the airplane. Ten days later, a World 

Airways DC- 10 landing at Logan Airport in 

Boston, Massachusetts ran off the end of the icy 

runway and into the bay, killing two passengers 

and injuring four others.“’ Spurred by those two 

accidents, the House subcommittee on aviation 

recommended that the FAA conduct a focused 

research and development program in runway 

friction measurement in an effort to improve 

safety in one of the critical areas of winter flight 

operations. The recommendation led to an 

appropriations bill for the FAA and NASA to 

“study the correlation between aircraft stopping 

performance and runway friction measurements 
on wet and contaminated surfaces.” The bill also 

specified that the research would focus on 

“determining if it is possible to predict aircraft 

stopping performance based on runway friction 

measurements using new technology friction 

measuring devices.”” 

The FAA, NASA and other groups had 

actually been studying runway friction and the 

effects of wet, snow-covered, icy, or otherwise 

“contaminated” runway surfaces on aircraft 

performance for some time. Engineers at the 

Langley Research Center, for example, had been 

investigating the impact of different runway 

surfaces on braking performance since 1968. Yet 

by 1982, pilots still had to rely solely on the 

subjective reports of other pilots landing or 

departing ahead of them for information on 

runway conditions. These reports were imprecise 

and often of limited value, because what was 

“adequate” for a Northwest Airlines pilot 

accustomed to flying in winter conditions might 

be considered “severe” by an Air Florida pilot. 

Ground-based friction-measuring vehicles were 

in existence in 1982, but they were only used to 

tell airport operators when repairs needed to be 

made to runway surfaces. The research 

recommended by the House subcommittee was 

an effort to provide pilots and airport operators 

with more precise and reliable information about 

7’he Roeing 737 nnd 

A TO15 rercwc-hm 

iciorkivig on the riirzuiriy 

,&-tion teJts in I988 nt 

Wn/fop Ffi‘yht Adi<y. 

runway conditions in bad weather. Pilots could 

then either modify their landing technique to 

accommodate the conditions or, if performance 

was degraded beyond a minimum safety level, 

operations could be suspended until the runway 

conditions improved. I’ 

Researchers wanted data from more than one 

kind of transport aircraft, so both NASA’s TSRV 

737 and a Boeing 727 owned by the FAA were 

used for the tests, although the FAA airplane did 

not have the extensive research equipment or 

capabilities of the 737. NASA technicians 

installed a special instrumentation packet on the 

727 to enable it to collect the necessary friction 

data for the research experiments, but the 737 

was still able to collect more detailed 

information, such as how hard the pilots were 

braking during the test runs. The tests, which 

ran from June 1983 through March 1986, took 

place at NASA’s Wallops Island Flight Facility 

and the Langley Air Force Base in Virginia, the 

FAA Technical Center in New Jersey, and at the 

Brunswick Naval Air Station in Maine. The 

tests were conducted at numerous sites so data 

could be collected in a variety of weather 

conditions, and researchers could evaluate the 

impact of different runway surfaces on braking 

friction as well as the quality of the ground 

vehicle measurements. 

I10 Airborne 7 kiiilbhizer 
The research effort evaluated a number of 

different ground friction measuring devices. A 

diagonal-braked vehicle (DBV), for example, was 

a car with a specially modified braking system 

that allowed only two diagonally opposed tires to 

lock up when the brakes were applied sharply. 

The DBV measured the speed, acceleration and 

stopping distance from the point of brakedwheel lockup to determine the friction level of 

the runway. Another ground device called a 

Mu-Meter consisted of a 540 Ib. trailer towed 

behind a truck that determined surface friction 

by measuring the side-forces imposed on the 

trailer wheels. A third ground vehicle, called a 

BV-11 Skiddometer, measured the speed of the 

vehicle, the torque applied during braking, and 

the slip ratio of an instrumented wheel to 

determine the runway friction level. Over the 

course of the tests, half a dozen different ground 

vehicles were evaluated at different locations. 

The tests were conducted by having a 

ground vehicle make a pass down the runway 

first, followed by one of the two test airplanes. 

The measurements of the ground device and the 

airplane would then be compared. Braking 

performance was measured over a range of 

speeds, ranging from 40 mph to over 100 mph. 

For the slower runs, the aircraft would accelerate 

to the required speed and then apply maximum 

braking, but for the faster runs, the aircraft 

would take off, land, and then test the braking 

performance as it slowed down to a stop. The 

research also looked at the impact of engine 

reversers on aircraft braking performance in 

contaminated runway conditions, and the 

effectiveness of different kinds of runway deicing 

substances. '' 

Measurements were taken on a wide variety 

of runway surfaces and conditions. Dry runway 

measurements were taken to establish the 

standard against which degraded performance 

could be measured. Tests were then conducted 

on wet, flooded, slush-covered, snow covered 

and icy runways. In some cases, natural rainfall 

allowed researchers to measure the impact of 

both surface water levels and the intensity of 

rainfall on runway friction levels. If it was not 

raining, wet runway conditions could be created 

by flooding surfaces with water trucks. Some of 

the winter conditions would have been harder to 

simulate but, fortunately, that was not necessary. 

The TSRV 737 and its research crew 

travelled to the Brunswick Naval Air Station in 

March 1985 to test runway friction levels in 

snow and icy conditions. The researchers wanted 

to test snow levels up to eight inches, and 

immediately after the plane arrived, eight inches 

of snow fell. A 2,000 foot test section of snow 

was prepared, with a long cleared strip at either 

end to allow the airplane to stop and turn 

around. The first thing the researchers 

discovered was that eight inches of snow 

increased the friction level so much that 

although the 737 finally reached the 90 knot 

speed the test required, the snow caused so much 

drag that the aircraft could never have reached its 

takeoff speed. The snow was progressively 

reduced for additional tests with six, four and 

two inches of snow, by which time the 

conditions had deteriorated into the precise kind 

of slush conditions the researchers wanted to test 

next. After the snow measurements were 

completed, the temperature at New Brunswick 

fell, allowing the runway to be frozen for the 

icing tests. The lack of friction on ice-covered 

runways became very clear when the 737 

accelerated to 90 knots as it entered the icecovered section and, despite maximum braking 

efforts by the pilot, exited the section at 92 

knots." 

The runway friction tests showed researchers 

that the ground vehicle measurements correlated 

extremely well with aircraft performance, 

meaning that they could be used to give pilots 

and airport operators reliable information about 

runway friction conditions in bad weather. The 

results also indicated that grooved runway 

surfaces were an extremely effective method of 

maintaining safe friction levels in poor weather 

conditions. Braking performance on transversely 

grooved runway surfaces was almost as good in 

wet and slippery conditions as it was on dry 

runways. These results played a significant role 

in expanding the use of grooved surfaces in the 

transportation industry. By 1993, over 800 

commercial runways in the world were 
The helmet-mounted 

display being tested on 

the ground at Langley 

Research Center in 1989. 

Dr. jeremiah F. Creedon, 

director for Flight System 

at Langhy, in the middle, 

looks on. 

constructed with grooved surfaces. In addition, 

sections of highway in all 50 states within the 

U.S. were using grooved surfaces to improve 

traction in poor weather. While most of the 

highway applications used longitudinal grooving 

for ease of installation, transverse grooving was 

also being installed at an increasing number of 

intersections to improve braking performance." 

The use of ground vehicles for frictionmeasuring also increased dramatically as a result 

of the NASA/FAA tests. Before the runway 

friction research, fewer than a dozen airports had 

the machinery, and there were no guidelines to 

tell operators how to use the devices to judge 

friction levels in poor weather. By the early 

199Os, between 80 and 100 airports had 

purchased ground friction-measuring devices. In 

addition, the FAA issued advisory circulars that 

spelled out what the minimum friction 

measurements should be for each different 

vehicle in various conditions to ensure safe 

aircraft braking performance. Airport operators 

now had a much more reliable method for 

judging the safety of runway conditions and 

knowing when operations should be suspended. 'I' 

I! \L 

Helmet Mounted Display 

The helmet mounted display research with 

the TSRV 737 stemmed from research the 

McDonnell Douglas Corporation was 

conducting on the X-30 National Aerospace 

Plane (NASI'). Engineers working on the X-30 

faced a number of formidable design challenges. 

The plane was supposed to take off from a 

conventional runway, go into space and travel at 

hypersonic speeds, and then re-enter the earth's 

atmosphere and land once again on a runway. 

The performance requirements of such an 

vehicle required the design to be as light, 

streamlined and as simple as possible. One 

potential strategy for saving significant amounts 

of weight and drag was to design the aircraft 

without any cockpit windows. Under normal 

conditions, it was argued, automatic landing 

systems and advanced flight displays could safely 

guide the aircraft without any direct outside 

visibility for the pilots. In order for such a 

revolutionary design to be acceptable or even 

considered, however, it still had to afford the 

pilots some way of flying and landing the aircraft 

I12 Airborne Eudbhzer 
visually in case of an emergency. 

working on the X-30 cockpit design came up 

with an idea for a helmet-mounted display that 

would use television cameras or sensors in the 

nose of the airplane to provide the necessary 

visual display of the outside world for the pilots. 

A helmet mounted display would be more 

flexible than a fixed cockpit display, because it 

could track the pilot’s head movements and 

show him the specific portion of the outside 

scene where his eyes were “looking.” Helmet 

mounted displays were already being used in 

military helicopters, but they had never been 

tested for basic control of a transport aircraft in a 

cockpit that had absolutely no outside visibility. 

The TSRV 737 was a far cry from the X-30. 

But the McDonnell Douglas engineers knew the 

737 was involved with state-of-the-art cockpit 

displays, and the windowless aft flight deck on 

the airplane seemed like the ideal place to test 

the viability of a synthetic vision system. The 

research systems on the aircraft were also set up 

to incorporate new experiments with a 

minimum of effort. So the McDonnell Douglas 

researchers approached NASA with a proposal to 

test a helmet mounted display system on the 

airplane, and the managers at Langley agreed. 

McDonnell Douglas would provide the 

experimental technology, and NASA would 

provide the testbed and flight time. 

was simply to test the basic viability of the 

helmet display concept, the test system was 

constructed from crude, off-the-shelf 

components. Two television cameras were 

mounted in the nose of the 737, giving the pilot 

a total field of regard 80 degrees across and 30 

degrees high. Within that area, the pilot’s field of 

view at any given moment was 40 degrees wide 

and 30 degrees high. The images conveyed by 

the cameras were displayed on two eyepieces in 

the pilot’s helmet. Because the display was to be 

used for basic aircraft control, critical flight data 

including altitude, airspeed, flight path angle and 

flight path acceleration were superimposed on 

the televised image.” 

McDonnell Douglas researchers who were 

Since the purpose of the flight experiments 

Although the McDonnell Douglas engineers 

Radome of the Boeing 

737 testbed aircraj, used 

to provide information to 

the helmet mounted 

dipkzy. 

had initially envisioned using the aft cockpit of 

the 737 for the test flights, they wanted to be 

able to compare the results of the helmet 

mounted display landings with conventional 

landings using outside visual references. Visual 

landings had to be made from the 737’s forward 

cockpit, and the controls and displays in the aft 

flight deck were dramatically different from 

those in the front. In order to make a valid 

comparison of landing accuracies with and 

without the helmet display, therefore, all the 

landings had to be done from the forward 

cockpit. Since safety considerations precluded 

the front cockpit windows from being covered, 

the visor of the helmet used for the synthetic 

vision display was painted a flat black color and 

kept down over the pilot’s eyes during the 

helmet-guided landings. 

The helmet mounted display system was 

tested by two NASA research pilots and two 

pilots from McDonnell Douglas. In addition to 

practice time in a ground simulator, each pilot 

made a minimum of 14 visual landings to 

NASA’s Wallops Island Flight Facility and 

observed an additional 14 landings through the 
Measuring aircrafi skids 

during the runway 

friction tests. 

helmet mounted display before attempting any 

landings with the synthetic vision system. In 

evaluating the system, the McDonnell Douglas 

engineers wanted to compare both the pilots' 

perceived workload and the accuracy of the 

landings with and without the helmet display. 

While the Wallops Island airport was equipped 

with laser tracker that could provide data on the 

accuracy of the landings, the researchers wanted 

to give the pilots immediate feedback on how 

close they had gotten to the target landing spot. 

To obtain that information, ground personnel 

ran out onto the runway immediately after each 

landing and found the sticky rubber patches that 

marked where the 737's tires had just touched 

the runway. The distance between those marks 

and the target point was then quickly measured 

and radioed to the flight crew on the airplane. 

The test flights were conducted throughout 

May and June of 1989. A total of 67 landings 

were completed using the helmet display system, 

with very favorable results. The accuracy of the 

landings with and without the helmet display 

were almost identical, although pilots reported 

that their workload was higher for the landings 

using the synthetic vision system. There were 

also some difficulties caused by the limitations of 

the test equipment, such as an image processing 

time lag that made pilots reluctant to move their 

head once they were on 3 short final approach. 

Still, the flights showed that a helmet mounted 

synthetic vision system could be used to land a 

transport airplane." 

Although the helmet mounted display tests 

had been very successful, the X-30 manned 

vehicle program was abandoned in 1992. 

McDonnell Douglas continued funding some 

helmet display research for military applications, 

since windowless cockpits could potentially help 

shield aircraft from both radar detection and 

laser weapons. The McDonnell Douglas 

engineers also believed the concept might one 

day find its way into another advanced transport 

aircraft design" Hut while the future of the 

helmet mounted display system was still 

uncertain, there was no question that the TSRV 

737 had been useful in its initial development. 

The 737 allowed the McDonnell Douglas 

engineers to test the basic viability of the 

concept, economically and in actual flight 

conditions, before investing large amounts of 

company funds and staff time in fully developing 

the technology. 

Airport '85 

Perhaps the most unusual experiment ever 

conducted with the TSRV 737 was a flight test 

program for the Air Force in 1985. Air Force 

officials were apparently concerned that aircraft 

operating out of the new airport planned for 

Denver, Colorado would block critical 

communications between orbiting satellites and 

receiver antennas at Buckley Air National Guard 

Base, which was located just west of the airport 

site. The best way to determine if the airliners 

would really cause a problem was simply to fly a 

transport aircraft through the signal beam and 

see if it interfered with the transmission. The 

difficulty with this approach was that to intersect 

the beam, an aircraft had to navigate through a 

constantly moving three-foot square hole in the 

sky. The Air Force also wanted the tests 

completed in only three or four months. 

aircraft that could perform that kind of 

demanding precision navigation and could 

conduct the flight test in that short a period of 

time, the Air Force finally approached NASA 

about using the TSRV 737. The 737 had an 

extremely precise guidance system that could be 

programmed to indicate course deviations as small 

as a few feet, and its velocity vector electronic flight 

displays allowed the pilot to see not only the 

attitude of the aircraft, but the exact flight path it 

was following. NASA agreed to support the Air 

Force effort, and Langley engineers began work on 

the project in the spring of 1985. 

In order for the 737 to achieve the precise 

accuracy the Air Force tests required, the 

research flights were designed to use guidance 

from two different sources. Thc initial flight 

path fbr each run was designed on board the 

aircraft and put in to the navigation co m p ci te rs, 

which then generated a magnetic course for the 

pilot to follow. The flight path had to be 

After an unsuccessful search for an Air Force 
designed on board the airplane because the target 

was constantly moving. Each new test run 

required a different flight path. The second 

source of guidance came from an extremely 

precise Marine Corps fire control radar on the 

ground. The Marine personnel called small 

course corrections over a radio frequency to the 

research pilot, as well a countdown to the 

intersection point with the target. The 

countdown was important because at the precise 

moment the airplane intersected the target, the 

Air Force wanted the 737 to pitch up to a 30 

degree nose-high attitude. Although the 

approach to the target had to be flown from the 

aft cockpit to control the flight path with the 

precision the tests required, the aft cockpit flight 

controls could only command half deflection of 

the 737's control surfaces. To get an rapid pitchup of 30 degrees, command of the airplane had 

to be handed over to the front cockpit. The 

countdown helped the research pilots execute the 

transfer of command and the pitch-up maneuver 

at the exact moment the plane intersected the 

target. 

To add to the challenge of the flight tests, all 

the electronic displays in the 737's aft cockpit 

malfunctioned just before the Denver flights. In 

1985, the airplane was still equipped with the 

original experimental, monochrome General 

Electric flight displays, and they had a history of 

maintenance difficulties. Unfortunately, there 

was not enough time to repair the displays and 

still get the Air Force tests done on time. So 

NASA research pilot Lee Person had to fly the 

tests with only an electromechanical Course 

Deviation Indicator (CDI) in the aft cockpit for 

course guidance. The CDI was a standard 

navigation instrument that indicated the 

aircraft's relative position to a selected course. If 

the needle on the CDI was centered, the plane 

was on course. If the needle was left or right of 

center, it indicated that the airplane needed to 

turn left or right to get back on the correct path. 

Since the CDI NASA used for the Air Force 

A 'Lath scale model of the 

Boeing 737 undergoing 

wing tests in the Langley 

Research Center wind 

tunnel. This research 

testedflow physics over 

the aircra$ wing. Over 

7OOpressureports were 

~ fil/lrnl -_.--- ~ nw " ,, ... tho - '.e.. rirrht-hnnrl 

wing to measure ai$aw. 
An electronic disphy of a 

“boustrophedonic”fLlight 

path the 737 created and 

followed to map the ILS 

signal at the Los Angeles 

lnternationnl Airport. 

flight tests received its guidance from the Marine 

Corps fire control radar, however, it indicated 

much smaller course deviations than a standard 

instrument would. The autopilot control knobs 

were also modified to allow much more precise 

corrections in the flight path. Instead of the 

usual configuration, in which each click of a 

knob altered the airplane’s track angle by one 

degree, the controls were altered so that each 

click changed the track angle only one-tenth of a 

degree. As a result, Person was able to make 

corrections as small as one or two feet. ’‘I 

on board the airplane, the course corrections 

radioed from the Marine fire control radar and 

the precision autopilot control of the airplane, 

the NASA research pilots were able to repeatedly 

find and intersect the moving, one-meter cube in 

space they were seeking. The Air Force was 

extremely satisfied with the results, and the 

NASA personnel who worked on the project 

were justifiably proud of what they had done. 

Between the computer-generated flight paths 

The task they had undertaken had been so 

difficult that not even military aircraft had been 

able to accomplish it. Yet the 20-year old 737 at 

Langley and its crew of researchers had not only 

completed the mission successfully, but they had 

done it on budget, and on time. The 737 was 

proving itselfa much more flexible and capable 

resource the early TCV program researchers had 

ever imagined it could be. 

ILS Signal Modelling 

In 1332, the FAA began investigating 

whether it would be possible to decrease the 

distance between the long, parallel runways at 

the Los Angeles International Airport (LAX) 

and still maintain safe separation bctween 

aircraft on approach to the airport. If the space 

between the runways could be reduced, it would 

allow the construction of more runways on the 

airport, which would boost the airport’s capacity. 

Since LAX controllers typically assigned airliners 

I 16 Airborne 7 idbkzzer 
long, straight-in approaches from 30 or 40 miles 

away, however, analysts needed information on 

how accurate the standard Instrument Landing 

System (ILS) signal was at those distances in 

order to determine whether more closely spaced 

approach courses would be safe. 

enlisted the assistance of the TSRV 737. The 

NASA 737 had the ability to gather extensive 

data on the ILS signal characteristics, and its 

computers could also design and fly precise, 

complex navigation routes that could cover the 

entire signal range. Specifically, the FAA wanted 

the airplane to fly evenly spaced, descending “S” 

turns across the ILS signal, starting from a point 

30 miles away from the airport. One of the 

NASA researchers dubbed the back-and-forth 

navigation course a “boustrophedonic” flight 

path, which sounded very impressive and 

technical. It was not until some time later that 

the other engineers looked the term up in the 

dictionary and discovered that it meant simply, 

“as the ox plows.”” 

The Los Angeles ILS modelling research 

took place on April 1-3, 1992. The flights had 

to be conducted in the middle of the night so 

the experiment would not interfere with the 

normal airport traffic, but they were uneventful 

and obtained the ILS data the FAA analysts 

needed to explore expansion options at LAX. 

The experiments also allowed NASA researchers 

to compare the accuracy of a differential global 

positioning system (GPS) signal against that of 

the ILS, so both the FAA and NASA obtained 

some valuable information from the research. 

The ILS modelling work at LAX was not a 

large or complex research project. Nevertheless, 

In order to gather that information, the FAA 

it involved a task that would have been difficult 

or impossible for any airplane without the 

TSRV’s unique equipment and capabilities to 

perform. The NASA airplane, on the other 

hand, was able to complete the research relatively 

easily and in a timely manner. The LAX flights 

demonstrated once again that the TSRV 737 

could support not only ATOPS program-related 

research, but a variety of other tasks and research 

efforts for NASA, industry, and other 

government agencies. 22 

Summary 

When NASA purchased the prototype 

Boeing 737, it was to be used as a support 

system for a specific research program. The 

engineers who designed the TCV program did 

not expect the airplane to be used to test helmet 

mounted synthetic vision systems, to gather data 

on flow physics, or to find three-foot wide holes 

in the sky for the United States Air Force. But in 

designing a research tool to flight test advanced 

transport concepts, the NASA and Boeing 

engineers ended up creating an ideal testbed for 

a much broader range of technologies and 

research projects. The TSRV 737 may have 

begun as a test plane for a single research 

program, but it evolved into a national resource 

for airborne research. Like the many wind 

tunnels at the Langley Research Center, the 

NASA 737 provided both government and 

industry with a fully instrumented research 

facility for gathering data, testing new designs 

and demonstrating concepts to further 

aeronautical technology. 

Conclusion 

The Boeing 737 ‘yying 

hboratory ” injight on 

another research mission 

aspart of the Advanced 

Transport Operating 

Systems Program 

conducted nt NASA j 

Langley Research Center. 

esearch supported by the United States R government has played an important role 

in the advancement of aeronautics and the U.S. 

aviation industry since the formation of the 

National Advisory Council for Aeronautics 

(NACA) in 1915. Government involvement in 

research has allowed industry to pursue concepts 

that would otherwise have been too high-risk, 

long-term, or expensive to research and develop. 

It has also encouraged the development of 

technologies that benefit society but do not offer 

manufacturers or users enough of an economic 

incentive for industry to sponsor the research 

itself. As a result, government research 

institutions like NACA and its successor, the 

National Aeronautics and Space Administration 

(NASA), have contributed greatly to both the 

welfare of society and the economic health of the 

aeronautics industry and, consequently, the 

country as a whole. 

Although NACA and then NASA have 

always had to balance their aeronautics research 

efforts between near-term projects that have a 

more immediate benefit for industry and longterm endeavors that help build the nation’s 

technology base for future aircraft design, the 

organizations have always focused on finding 

pragmatic, technological solutions to the nation’s 

aeronautical problems. The original NACA 

charter called for the agency to “supervise and 

direct the scientific study of the problems of 

flight, with a view to their practical solution.”’ 

The mission statement of NASA’s Langley 

Research Center, one of the main government 

facilities for aeronautics research since 191 8, 

specifically calls for it to “perform innovative 

aerospace research relevant to national needs; 

transfer technology to users in a timely manner; 

and support U.S. government agencies, U.S. 

industry, NASA Centers, the educational 

community, and the local community.” The 

mission statement also notes that “Our success 

will be measured by the extent to which our 

research results and technologies contribute to 

the design, development, and operation of future 

aerospace vehicles and missions.”’ 

By these standards, the research conducted 

with Langley’s Boeing 737 Transport Systems 

Research Vehicle (TSRV), as part of the 

Terminal Configured Vehicle (TCV)/Advanced 

Transport Operating Systems (ATOPS) 

program, was extraordinarily successful. The 

program was created in 1973 specifically to 

research innovative technologies that could help 

solve some of the problems facing the national 

air transportation system. In the twenty years 

that followed, the airplane supported a wide 

variety of research projects with other NASA 

centers, the Federal Aviation Administration, the 

Department of Defense, industry manufacturers, 

and a number of universities. In addition, the 

transfer of technological information from the 

TCV/ATOPS program research was creative, 

timely and surprisingly effective, with the end 

result that the program and its research airplane 

had a significant impact on the development and 
I20 

application of a number of aeronautical 

technologies. 

The TSRV 737 was instrumental in the 

development and acceptance of electronic flight 

displays for transport aircraft, which led to the 

creation of ‘‘glass cockpits.” Its demonstrations 

of complex, curved path approaches using the 

Time Reference Scanning Beam (TRSB) 

microwave landing system (MLS) gave the 

U.S. candidate technology an unassailable 

edge in the international competition for a 

new instrument landing system. Years later, its 

research with global positioning system (GPS) 

approaches and autolands changed the nature 

of the entire debate about GPS and helped 

solidi@ the technology’s position as a serious 

contender to be a partial or total replacement 

for MLS. 

The windshear research conducted with the 

airplane led to the development of forwardlooking detection systems that gave airliners the 

ability to survive or avoid potentially lethal 

microbursts. The Digital Autonomous Terminal 

Access Communication (DATAC) data bus 

developed installed and tested on the TSRV 737 

became the basis for a new national design 

standard for transport aircraft data bus systems. 

The Total Energy Control System (TECS) was 

incorporated into an unmanned, high-altitude, 

long-range reconnaissance vehicle by the Boeing 

Commercial Airplane Company. The electronic 

Engine Monitoring and Control System 

(EMACS) display format developed by a Langley 

engineer and flown on the 737 was adopted 

almost immediately by a general aviation 

avionics manufacturer and was included in the 

tentative cockpit design for the McDonnell 

Douglas Corporation’s MD-XX airliner. 

profile descents the NASA engineers evaluated 

with the TSRV 737 were not supported by the 

air traffic control (ATC) system, the NASA 

experiments proved the potential value of the 

technique, and thc capability for time-based 

navigation eventually bcgan to be implemented 

into some new airliners. The ATC data link 

experiments with the 737 gave the concept a 

critical measure of credibility and support, 

Although the computer-driven, fuel-efficient 

Airborne Trtlilbhzev 

accelerating the acceptance and use of data link 

communication within the ATC system. The 

airplane also tested precision flare laws that 

helped Boeing engineers improve the autoland 

performance for several of Boeing’s transport 

aircraft. 

In addition, the TSRV 737 provided a 

highly capable testbed for numerous other 

successful research projects. The airplane helped 

conduct runway friction tests that proved the 

accuracy of ground friction measuring vehicles 

and the value of grooved runway and highway 

surfaces. As a result, airport operators gained 

access to reliable information about the safety of 

runway conditions, and the use of grooved 

surfaces increased at airports and on the nation’s 

highways. A joint flight test project with 

McDonnell Douglas proved that a pilot could 

use a helmet-mounted synthetic vision display to 

land a windowless transport aircraft. Because it 

was able to navigate successfully through a 

moving, meter-square spot in the sky, the TSRV 

737 was able to obtain critical information for 

the United States Air Force. The airplane’s flight 

research to model the instrument landing system 

(ILS) beam at the Los Angeles International 

airport gave the FAA valuable information about 

whether the runways could be spaced any closer 

together. 

Although the airplane was still flying and 

conducting additional research 20 years after it 

was purchased by NASA, it had already had a 

tremendous impact on the “design, development 

and operation” of new aircraft. Achieving those 

results was neither simple nor easy, however. 

The world of aeronautics had changed 

dramatically from the early days of NACA, when 

a simple cowling design could revolutionize 

aircrafi design and aircraft companies were 

clamoring to absorb whatever new knowledge or 

technology NACA could discover. The big 

problems facing the airlines in the 1970s were no 

longer ones of basic structures and 

aerodynamics. They were complex problems of 

getting aircraft to operate more efficiently and 

safely within an increasingly congested air traffic 

environment, and they required systems-oriented 

solutions. 
Systems solutions are themselves complex, 

however. They typically need input from 

numerous research disciplines and involve many 

more elements and people. Systems-oriented 

research looks not only at individual aircraft 

components, but also the interactions between 

those components and the rest of the aircraft 

systems, the pilots, the operation of the aircraft 

within the ATC system, and the aircraft’s 

compatibility with other air traffic in the 

vicinity. 

The TCV program was created to research 

this kind of system-oriented technology, and the 

program organization reflected the complexity of 

the kind of research it set out to conduct. The 

matrix structure that caused so many 

management difficulties with the program was 

used precisely because the TCV research 

required input from numerous technical 

disciplines. The program also began with a joint 

agreement with the FAA and included an on-site 

contingent of Boeing engineers for the first five 

years. Few of its research projects, in fact, were 

conducted without the involvement of more 

than one research discipline, one or more other 

government agencies, or industry. 

In addition to these kinds of challenges, the 

TCV/ATOPS program had to contend with the 

basic complexity of the technology development 

and transfer process. Both the selection of 

research projects and the eventual application of 

new technologies developed by the program were 

affected by political, social, economic and 

regulatory forces. The MLS demonstrations, for 

example, were initiated and then expanded 

because of the heated political controversy 

surrounding the international landing system 

decision. The windshear research was organized 

because of the political and social pressure 

following the 1985 crash of a Delta L-1011 

jumbo jet in Dallas Texas. The runway friction 

tests were funded after several airline accidents 

highlighted some of the dangers of winter flight 

operations. Even the basic funding for the TCV/ 

ATOPS program itself fluctuated widely 

depending on the administrative and political 

pressures at play throughout its 20-year history. 

Forces that had little to do with the intrinsic 

worth of the concepts researched through the 

TCV/ATOPS program also had a tremendous 

impact on the eventual application of those 

technologies in commercial products. New ideas 

faced a human and organizational tendency to 

resist change, and as companies grew in size, 

effectively communicating information about 

new innovations to all the necessary players 

became more difficult. More importantly, the 

airline industry had changed dramatically since 

the days when pilots and aeronautical engineers 

ran the companies. As new technology became 

more expensive to produce and incorporate into 

aircraft designs, it had to “earn its way” onto 

airplanes more than it had in the past. In other 

words, technological innovations had to offer 

significant economic or other tangible benefits to 

be incorporated into new airliners; a trend that 

became even more pronounced after 1978, when 

deregulation made the airline industry more 

competitive and cost conscious. 

aircraft, airlines also tried to keep cockpits of 

different aircraft relatively similar, both for safety 

and for training considerations. Dramatically 

new equipment could require retraining for all of 

an airline’s pilots, not to mention re-certification 

of an airplane design, both of which involved 

significant additional costs. As a result, even 

when new technologies were adopted, their full 

capabilities were often not used. The electronic 

attitude directional indicator (EADI) displays 

incorporated by Boeing in the 767/757s, for 

example, were formatted to duplicate an 

electromechanical instrument. Technologies 

such as MLS, profile descents or ATC data link 

communications faced even greater barriers to 

application, because they required changes in the 

ATC system, and airlines would not invest in 

equipment if the ATC system could not support 

its use. 

In view of all this, the achievements of the 

TSRV 737 and the TCV/ATOPS program in 

researching, developing and transferring 

aeronautics technology are even more striking. 

There were several factors that enabled the 

program to have such an impact, however. First, 

the program was focused on solving problems 

Because pilots typically flew more than one 
I22 

that were both relevant and important to the air 

transport industry. Second, industry engineers 

were involved in the program from the very 

beginning, and the TCVIATOPS research was 

critical role in the selection of the U.S. candidate 

MLS system by the International Civil Aviation 

Organization (ICAO). Flight demonstrations of 

the electronic map display in the 737 helped 

characterized by a high level of communication 

between NASA engineers and industry 

representatives. As a result, the NASA researchers 

were more aware of industry concerns and 

problems, and they were able to obtain valuable 

feedback and suggestions about their research 

while it was still in process. Furthermore, the onsite involvement of a contingent of Boeing 

engineers for the first five years of the program 

and the numerous cooperative research efforts 

between NASA and industry in the years that 

followed allowed groups of industry engineers to 

become extremely knowledgeable about the 

technologies the NASA program was evaluating. 

Those engineers, in turn, played an important 

role in convincing other company decisionmakers to invest in further development and 

application of the concepts. 

The most influential factor in the successful 

transfer of so many technologies from the TCV/ 

ATOPS program to practical applications, 

however, was the TSRV 737 airplane. The 

unique Boeing aircraft, with its two cockpits, 

computerized and highly capable systems, and 

easily reconfigured research equipment, allowed 

a wide variety of new technologies to be flown in 

an actual transport class aircraft and often in 

realistic flight conditions. This capability was 

important, because as technology became more 

complex and expensive, industry became less 

able or willing to invest in innovations that had 

been tested only in laboratories or simulators. 

The gap between that level of development and a 

commercial application was often too broad, and 

the risks involved were too high. Research and 

demonstration flights, however, gave technology 

a level of credibility that no amount of 

laboratory or simulation testing could achieve 

and allowed researchers to demonstrate its 

potential capabilities and operational benefits in 

a vivid, visual manner to government and 

industry leaders. The impressive, curved-path 

automatic landing demonstrations performed by 

the TSRV 737 airplane, for example, played a 

convince airline operators to support the 

inclusion of a similar display in Boeing’s new 

7671757 aircraft. 

further if it was going to be flight tested than if it 

was only going to be evaluated in simulations. 

Details and problems that wouldn’t come into 

play in a laboratory had to be resolved before a 

technology would work on an airplane. 

Consequently, developing commercial 

applications for flight tested concepts entailed 

fewer risks for industry, which was an important 

consideration. Industry decision-makers also had 

more confidence in a technological innovation 

that had been successfully flight tested. Boeing, 

for example, knew that the DATAC data bus 

worked in theory. What gave the company the 

confidence to include the technology in its next 

transport aircraft design, however, was the fact 

that the TSRV 737 had used DATAC without 

difficulty throughout hundreds of flight hours. 

Most importantly, flight testing a new 

concept on the TSRV 737 provided essentially 

unassailable proof that the technology would 

work. The technique or innovation still might 

not prove economically viable, but a successful 

flight test ended the discussion about whether it 

could be done. The TSRV’s research flights with 

path-in-space flare laws, for example, ended the 

engineers’ debate about whether the theory was 

valid. And what made the airplane’s CPS-guided 

autoland flights so significant was not the 

technical performance of the system, but the fact 

that the airplane had actually completed 

automatic landings using GPS technology. The 

fact that the system still had to use a radar 

altimeter and the accuracy of the landings was 

not good enough to meet a Category I1 or 111 

certification standard was secondary. The NASA 

flight tests abruptly ended the debate about 

whether a CPS autoland was possible, and 

refocused the discussion and further research 

on what level of accuracy the technology 

could attain. 

Furthermore, a concept had to be developed 

Airborne Trailbhzr 
Of course, not all of the concepts flight 

tested with the TSRV 737 were picked up by 

industry or the FAA for practical application. 

Some did not prove viable, and logistical or 

economic issues overrode the technical worth of 

others. Nevertheless, the Boeing 737 TSRV 

proved immeasurably valuable in successfully 

researching and transferring advanced 

technologies and concepts from NASA to other 

government agencies and industry. It provided 

persuasive, visual evidence of a new technology’s 

potential advantages and often gave decisionmakers the necessary confidence in experimental 

concepts to support the development of practical 

applications. 

The value of NASA’s 737 research airplane, 

however, went beyond its ability to transfer 

technology to industry. The airplane also had a 

significant influence on the Langley Research 

Center itself. The fact that the TCVIATOPS 

program research included flight tests in a 

transport airplane kept its engineers focused on 

feasible technology and real-world air 

transportation problems. Since those researchers 

and engineers were drawn from various 

directorates around the center, that “real-world’’ 

anchor impacted attitudes throughout the 

facility. In addition, the Boeing 737 Transport 

Systems Research Vehicle provided the Langley 

center, already famous for its wind tunnels, with 

another kind of national research facility. The 

TSRV 737 offered government and industry a 

flexible, capable research platform that could test 

a wide variety of complex, systems-oriented 

technologies in a realistic flight environment. 

And as aeronautical problems became more 

complex, that kind of research facility was 

proving to be as important a national resource as 

the wind tunnels had been in the early days of 

flight, 

unique airplane. But the Terminal Configured 

Vehicle/Advanced Transport Operating Systems 

program was also a remarkable research effort. 

From the beginning, the TCV/ATOPS program 

involved complex relationships and 

organizational challenges, and both its research 

and the application of its findings were 

Without question, NASA’s Boeing 737 was a 

influenced heavily by political, business and 

economic factors. One of the managers who 

came to the TCV/ATOPS program from the 

Apollo space program concluded that the 

challenge of putting a man on the moon was 

relatively easy compared with trying to research 

and transfer technology to improve the air 

transportation sy~tem.~ 

succeed in spite of its complex internal and 

external challenges was because the people 

involved with the TSRV airplane and the TCV/ 

ATOPS program were as unusual as the research 

effort itself. The program never even would have 

existed if it were not for the vision of the Langley 

engineers who saw the need for a systemsoriented, subsonic air transport research program 

and argued successfully for the purchase of the 

prototype Boeing 737-1 00 airplane. Throughout 

its history, the engineers, researchers, and 

technicians who worked with the airplane and 

the program gained a reputation for having a 

enthusiastic, “can do” attitude that made many 

difficult research projects possible. The nature of 

the program attracted engineers who liked 

solving practical, real-world problems, and the 

resourcefulness and dedication of the technicians 

who worked on the plane was inspiring and 

contagious. Although it sometimes meant 

laboring all night in a freezing hangar to repair 

research systems, warming a computer 

component with a borrowed hair dryer, working 

by flashlights and generator power in order to 

finish a new data bus design, or pulling together 

a superhuman effort to repair and outfit the 

airplane in a few weeks instead of the months it 

should have taken, the people who worked with 

the TSRV 737 made sure that the plane 

successfully completed every single research 

project it was scheduled to conduct. 

staff worked so hard on the TCV/ATOPS 

research projects was that they believed what 

they were doing was extremely important, not 

only to NASA, but to the aerospace industry and 

the country itself. They knew the research they 

did with the TSRV airplane was going to do 

more than generate technical reports. If they 

One of the reasons the program was able to 

The reason the engineers, technicians and 
succeeded, their work could impact the landing 

system used around the world, revolutionize the 

information available to a new generation of 

airline pilots, and save lives. 

In retrospect, the TCVIATOPS program 

and the TSRV 737 did all of that and more. The 

prototype Boeing 737- 100 was originally 

purchased to support a single research program, 

which was expected to last only 5-6 years. 

Twenty years later, it was still performing an 

important role, not only for the TCV/ATOPS 

program, but for the Langley Research Center 

and the aerospace industry, as well. It had made 

significant contributions to the research and 

development of new aeronautical technologies 

that could help U.S. industry maintain a 

competitive edge in the global market, improve 

the operation of the national airspace system, 

and help save lives. The airplane might once 

have been an unwanted hulk on the ramp of the 

Boeing aircraft factory in Seattle, but the 

prototype 737-100 had become a national asset. 

The stubby transport airplane was not as 

glamorous as NASA's X-series research vehicles 

or as well known as the Space Shuttle, but the 

contributions it made were every bit as 

important. 
Chapter Notes 

Chapter I: NASA, Industry, and Technology: 

The Complex Nature of Progress 

Executive Office of the President, Office of Science and 

Technology Policy, Aeronautical Research and Technology 

Policy, Vol. I: Summary Report,, (Washington, D.C., 

November 1982), 13. 

Hans Mark and Arnold Levine, The Management of 

Research Institutions: A Look at Government Laboratories, 

NASA SP-481, (Washington, D.C., 1984), 265. 

The Denver Research Institute, “NASA Partnership 

with Industry: Enhancing Technology Transfer,” , NASACR-180-163, July 1983, X. 

Daniel P. Kaplan, Using Federal R&D to Promote 

Commercial Innovation, (Washington, D.C.: Congress of 

the United States Congressional Budget Office, 1988), 22- 

23. 

’ Aeronautical Research and Technology Policy, 1- 1 1. 

The phrase “technology development” has a number of 

different connotations for professionals involved in 

aeronautical research. In this chapter, and throughout the 

book unless otherwise specified, I use it only to describe 

the process of researching a concept to the point where a 

workable, test-ready piece of technology exists. I do not 

mean the process of developing a piece of technology to a 

point where it is ready for commercial application, which 

is a different matter. 

’ Office of Science and Technology Policy, Executive 

Office of the President, “Report of the White House 

Science Council, Federal Laboratory Review Panel,” 

(Washington, D.C., May 1983), 11. 

’ Herbert J. Cc!eman, “National Research Policy Aimed 

to Bolster Aviation,” Aviation Week & Space Technology, 

15 November 1982, 22; same idea also contained in: 

Aeronautical Research and Technology Policy, 9. 

’ Kaplan, Using Federal R&D, 10; Delmar Fadden, 

Boeing Commercial Airplane Company, interview with 

author, Seattle, Washington, 27 April 1993; William E. 

Howell, interview with author, Hampton, Virginia, 6 

April 1993. 

lo Executive Office of the President, Office of Science 

and Technology Policy, National Aeronautical R&D Goals: 

Agendafor Achievement, report of the Aeronautical Policy 

Review Committee, (Washington, D.C. February 1987), 

2. 

I’ 

technology and competitiveness, as quoted in: Christopher 

P. Fotos, “Industry Experts Say NASA Must Devote More 

Resources to Civil Aeronautics,” Aviation Week & Space 

Technology, 24 February 1992, 42; Robert S. Ames, “U.S. 

Must Understand the Link Between R&D and the 

Economy,” Aviation Week &Space Technology, 12 

October 1987, 149-50; Aeronautical Research and 

Technology Poliq, 15. 

Testimony before a House subcommittee on 

l2 Office of Science and Technology Policy, National 

Aeronautical R&D Goals, 3; Denver Research Institute, 

“NASA Partnership with Industry,” Appendix A-1, A-3, 

C-1; Ames, “R&D and the Economy,” 149-150; “First 

Steps Toward Competitiveness,” editorial, Aviation Week 

&Space Technology, 16 September 1991, 9; David F. 

Bond and Patricia A. Gilmartin, “Industry Collaboration 

Grows for Technology Development,” Aviation Week & 

Space Technology, 16 September, 1991, 20-23; 

Christopher P. Fotos, “Industry Experts Say NASA Must 

Devote More Resources to Civil Aeronautics,” Aviation 

Week &Space Technology, 24 February, 1992,42. 

’’ Thomas S. Kuhn, The Structure ofScient+c 

Revolutiens, 2nd ed., Foundations of the Unity of Science 

Series: Vol. 2, No. 2, (Chicago: University of Chicago 

Press, 1970), Chapter 11; Thomas P. Hughes, American 
Genesis: A Century of Invention and Technological 

Enthusiasm, 1870-1970, (New York: Viking Penguin, 

1989), 446-472; Derek J. de S. Price, Little Science, Big 

Science, (New York: Columbia University Press, 1963, 10, 

29, as quoted in: Arnold Pacey, The Culture of Technology, 

(Cambridge, MIT Press, 1983), 13, also 3-18. 

Mark and Levine, Research Institutions, 3-4; Hughes, 

American Genesis, 446-472; Pacey, Culture of Technology, 

13-34. 

Is Mark and Levine, Research Institutions, 5. 

“ Hughes, American Genesis, 71-74. 

Samuel A. Morello, interview with author, Hanipton, 

Virginia, 8 April 1993; David Hughes, “Glass Cockpit 

Study Reveals Human Factors Problems,” Aviation Week 

& Space Technology, 7 August 1989, 32-36; David 

Hughes, “Pilots, Research Studies Give Mixed Reviews to 

Glass Cockpits,” Aviation Week &Space Technology, 23 

March 1992, 50-51; Breck W. Henderson, “NASA Ames 

Pushes Automation Toward Human-Centered Design,” 

Aviation Week &Space Technoloa, 23 March 1992, 69-70. 

IX The National Aeronautics and Space Act of 1958, as 

quoted in the Dcnver Research Institute, “NASA 

Partnership with Industry,” Appendix, B-I. 

Io “The NASA Program of Industrial Applications,” 

(Address by Louis B. C;. Fong, Director, Office of 

Technology Utilization, NASA, at the Third National 

Conference on the Peacefill Uses of Space, Chicago, 

Illinois, 8 May 1963), from NASA Historical Archive files. 

”I TRWElectronics & D4ense/Quest, Winter, 1982-1 983, 

p. 65, as quoted in: the Denver Research Institute, “NASA 

Partnership with Industry,” xx. 

‘I Kuhn, Scicntijc Revohtiom; Joel Arthur Barker, Future 

Edge: Discovering the New Paradigms of Success, (New York: 

William Morrow & Company, 1992). 

Hughes, American Genesis, 456-6 1 ; Barker, Future 

Edge, 140- 149. 

’.’ AI Ries and Jack Trout, Marketing Wa@re, (New 

York: Penguin Books USA Inc., 1986) 83-99; Kuhn, 

Scientijc Revolutions; Barker, Future Edge, 55-70; R.P. 

Schniitt, et al., “Technology Transfer Primer,” Wisconsin 

U niversity-Milwaukee, Center for Urban Transportation 

Studies, l:HWA/TS-84/226, July 1985, 3; Howell, 

interview, 6 April 1993. 

E. Howell, “Integrated Controls for a New Aircraft 

Generation, Astronautics &Aeronautics, Vol. 16, No. 3, 

March 1978,48-53; R.P. Schmitt, et al., “Technology 

Transfer Primer,” 4. 

*‘ James Ott, “White House Calls for Changes in 

Procurement Procedures,” Aviation Week & Space 

Technolojy, 25 November 1985, 28; Robert Dunn and 

H.W. Withington, Boeing Commercial Airplane 

Company (retired), interview with author, Seattle, 

Washington, 27 April 1993; Alan Mulally, Boeing 

Commercial Airplane Company, interview with author, 

Seattle, Washington, 28 April 1993; John Warner, Boeing 

Commercial Airplane Company, interview with author, 

Seattle, Washington, 27 April 1993; Thomas Walsh, 

interview with author, Hampton, Virginia, 6 April 1993. 

l7 Dr. Jeremiah F. Crccdon, ct al., “NASA Technology 

Transfer,” report of the Technology Transfer Team, 21 

December 1992. 

lX Creedon, et al., “NASA Technology,” 142; Leo S. 

Packer, “Proposal for Enhancing NASA Technology 

Transfer to Civil Systems,” 26 September 1969, 

(unpublished document, from NASA Historical Archives), 

20; Denver Research Institute, “NASA Partnership with 

Industry,” x - xix, Appendix D-5; Schmitt, et a]., 

“Technology Transfer Primer,” introduction, 1, 5; 

“Government Focus on Data Transfer to Industry Urged,” 

Aviation Week & Space Technology, 23 July 1984, 13 1 ; 

Kaplan, Using Fedeml RdD, 49; Warner, interview, 27 

April 1993; Howell, interview, 6 April 1993; Fadden, 

interview, 27 April 1993; Anthony A. I,mibregts, Boeing 

<:ommercial Airplane Company, interview with author, 

Scattle, Washington, 26 April 1993. 

‘‘I Howell, interview, 6 April 1993; Jeremiah F. Creedon, 

interview with author, Hanipton, Virginia, 5 April 1993; 

Warner, interview, 27 April 1993; Fadden, interview, 27 

April 1993. 

“’ H.W. Withington to John 1’. Itecdcr, Lcttcr, 6 June 

1979 (from the ATOPS office files) 

” 

Special Initiatives l’eam on ’l‘echtiology Transfer report, 

from NASA News press release dated 8 lanuary 1993. 

Daniel S. Goldin, coninicnts upon the release of thc 

Chapter 2: Addressing the New Challenges 

of Air Transportation: The TCVlATOPS Program 

Oran Nicks, phone interview with author, Hanipton, 

Virginia, 5 May 1993. 

126 

?1 1)iscusscd in numerous interviews, hut at length in: 

Howell, interview, 6 April 199.3. 

’’ Ilenver Research Institute, “NASA Partnership with 

Industry,” Appendix, 11-3; William D. Mace and William 

Setiatc (:omniittcc on Acron;itrtical ;ind Spiice Scienccs, 

Aeronnuticnl I?esearrh rind Development Policy Kprt, 90 th 

Chngress, 2nd scss., 1968, S. Kept. 957. 

‘ Barry Graves, phone interview with author, Minneapolis, 

Airborne Trailbhzer 
Minnesota, 20 April 1993; Thomas M. Walsh, interview 

with author, Hampton, Virginia, 6 April 1993; Robert 

Taylor, interview with author, Hampton, Virginia, 7 April 

1993; Seymour Salmirs, personal notes, 1969-1974 and 

phone interview with author, Minneapolis, Minnesota, 20 

April 1993; Samuel A. Morello, interview with author, 

Hampton, Virginia, 8 April 1993; Jack Reeder, personal 

files, 1969-1971. 

Department of Transportation and National Aeronautics 

and Space Administration, Civil Aviation Research and 

Development Policy Study, DOT TST-10-4, NASA 

SP-265, (Washington, D.C., March, 1971), 2-3 2-6. 

Roland L. Bowles, interview with author, Hampton, 

Virginia, 5 April 1993; ATOPS program presentation 

viewgraphs, from Flight Systems directorate files. 

‘ Civil Aviation Research and Development Po‘olicy Study, 2-4 

2-6. 

’ Thomas M. Walsh, interview, 6 April 1993; Seymour 

Salmirs, presentation materials for briefing to NASA 

Associate Administrator Lovelace, 1974; Heinz Erzberger, 

phone interview with author, Hampton, Virginia, 5 May, 

1993. 

Jack Reeder, Proposalfor Systems Research Approach to 

Integrating Vehicle-lnstrtlment-Display-Pi~t Capability for 

Total Flight Missions, draft, 1969, annotated with 

additional personal notes, 1971; Oran Nicks, interview, 5 

May 1993; Thomas M. Walsh, interview, 6 April 1993; 

Robert Taylor, interview, 7 April 1993; Draft RTOP 133- 

6 1 -, Advanced Operating Systemsfor Conventional Takeoff 

and Landing Aircrafi, prepared by Jack Reeder and Bob 

Taylor January 14-24, 1972, and annotated with personal 

notes by Jack Reeder. 

NASA Langley Research Center, Terminal Configured 

Vehicle Program Plan, (Hamton, VA, December 1, 1973), n 

L. 

I” Ibid, 4-24. 

Langley Research Center Central Correspondence Files, 

Ed Cortright memo to NASA Headquarters requesting 

permission for sole source procurement of the Boeing 737- 

100, 16 Occober 1972; Jack Reeder presentation notes, 

Reasonsfor 737 Choice, 12 July 1972. 

I’ Bernard Hainline, retired, Boeing Commercial Airplane 

Company, interview with author, Seattle, Washington, 26 

April 1993; H.W. Withington and Robert Dunn, retired, 

Boeing Commercial Airplane Company, interview with 

author, Seattle Washington, 27 April 1993; Richard A. 

Peal, Boeing Commercial Airplane Company, interview 

with author, Seattle, Washington, 28 April 1993. 

’’ Richard A. Peal, interview, 28 April 1993; Samuel A. 

Morello, interview, 8 April 1993; David C.E. Holmes and 

Wesley C. Easley, interview with author, Hampton, 

Virginia, 9 April 1993; Memorandum to Research Aircraft 

Flight Division files from Seymour Salmirs, Aero-Space 

Technologist, Flight Programs Branch, RAFD, 13 July 

1972, summarizing visit to Boeing Company in Seattle, 

Washington, to take first look at the company’s prototype 

737, PA-099. 

l4 Numerous books have been published about the 

United States SST program controversy. For example, see: 

Me1 Honvitch, Clipped Wings: The American SST 

Conflict, (Cambridge, Mass: MIT Press, 1982). 

Is “Supersonic Transport Advanced Electronic Display 

Proposal,” summary of program objectives and criteria, 

with trip report (dated 20 September 1971) by Seymour 

Salmirs, Aero-Space Technologist, Flight Programs 

Branch, Research Aircraft Flight Division to Director for 

Aeronautics, summarizing 14 September 1971 meeting at 

Boeing Company for review of the program (from private 

files of S. Salmirs); Bernard Hainline, viewgraph of NASA 

TCV Program Evolution, personal work notes collection 

and interview with author, Seattle, WA, 26 April 1993; 

H.W. Withington and Robert Dunn, interview, 27 April 

1993; Year By Year: 75 Years ofBoeing History 1916-1991, 

Boeing Historical Archives, (Seattle, Washington, 

November 1991), 101-1 13; Agenda, “DOT/SST Phase I1 

Technology Follow-On Advanced Electronic Display 

System )ADEDS) - Task VI, Inter-Agency Council 

Review,” The Boeing Company, Seattle, Washington, 27- 

28 September 1972; Attendance Lists, “DOTEST 

Follow-On Technology - Phase 11, Inter-Agency Council 

Review No. 2,” 21-22 March 1973, “Inter-Agency 

Council Review, Flight Control Development,” 1 1 

September 1973 and “Inter-Agency Council Review, 

Advanced Electronic Displays System (ADEDS) - Task 

VI,” 12 September 1973 (from private files of S. Salmirs). 

Seymour Salmirs job order, under Research and 

Technology Resume No. 133-, All-Weather Airborne 

Systems Study, 1 October 1971. 

” Siegbert Poritsky, interview with author, Washington, 

D.C., 13 April 1993; Thomas M. Walsh, interview with 

author, Hampton, Virginia, 6 April 1993; Jeremiah F. 

Creedon, interview with author, Hampton, Virginia, 5 

April 1993; Samuel A. Morello, interview, 8 April 1993; 

William E. Howell, interview with author, Hampton, 

Virginia, 6 April 1993. 

Agreement Between the Federal Aviation Administration 

and National Aeronautics and Space Administration 

Concerning Cooperation to Achieve Improved Terminal Area 

Operations, 3 May, 1973. 

‘I D. H. Cosley and R.A. Peal, “Advanced Electronic 

Display System (ADEDS) Flight Test Report, Vol 111 - 

Flight Test Results,” FAA-SS-22-3, technical report, July 1974. 
I 28 

’” Richard A. Peal, interview, 28 April 1993; Richard A. 

Peal, personal notes; TSRV 737 flight records, from 

ATOPS office files. 

Note: The Boeing 737 airplane purchased by NASA 

was actually referred to by several different names. It was 

called the Research Support Flight System (RSFS), the 

Terminal Configured Vehicle (TCV), and the Transport 

Systems Research Vehicle (TSRV). Since the TSRV label 

outlasted the other two, the airplane is referred to by that 

title throughout the book to help avoid confusion. 

‘I 

display was usually referred to as the Electronic Attitude 

Directional Indicator (EADI) and the map display was 

called the Electronic Horizontal Situation Indicator 

(EHSI), but these terms are no longer used. The accepted 

terms for these displays are now the Primary Flight 

Display and the Map, or Navigation, display. 

During the TCV program research, the primary flight 

” David C.E. Holmes and Wesley C. Easley, interview, 9 

April 1993; TSRV flight logs, (from ATOPS office files). 

2’ Seymour Salmirs and Harold N. Tobie, “Electronic 

Displays and Digital Automatic Control in Advanced 

Terminal Area Operations,” AIAA Paper No. 74-27, 

presented at the AIAA 12th Aerospace Sciences Meeting, 

Washington, D.C., January 30-February 1, 1974.; Samuel 

A. Morello, et al, “Flight-Test handling Qualities 

Documentation of the Research Support Flight System,” 

NASA-TM-X-726 18, October 1974. 

’’ Jeremiah F. Creedon, interview with author, Haniptoti, 

Virginia, 7 May 1393. 

‘5 Ilavid <:.E. Holmes and Wesley C. Easley, interview , 9 

April 199.3: Roland I.. Bowles, interview, 5 April 1993. 

The organizational structure of the Langley Research 

Center was essentially a vertical one. Under the director of 

the center were half a dozen or so “Ilirectorates” (the 

number varied slightly over the years). The next level 

beneath :I Directorate was a Division. The next step down 

from a division was a branch, and underneath that was a 

section. 

’ Lingley Research Center Announcement No. 54-73, 

“F,stablishment of Terminal Configured Vehicles Program 

Office,” (from ATOPS office files). 

’’ James I<. Hansen, Engineer in C/itrrge: A History of the 

Langley Aeronaittical Laboratory, 191 7-1958, (Washington, 

I). C. : N ;i t io nal Aeronautics and Space Ad ministration , 

1987), 24-32, 58. 

”’ I3arry (;raves, interview, 20 April 1993: Jeremiah F. 

(:reedon, interviews. 5 April 109.3 and 4 May 103.3; 

William F.. Howell, interview, 0 April 1993; Samuel A. 

Morello, interview, 8 April 199.3; William F. White, 

Airborne Trailbhzer 

interview with author, Washington, D.C. 13 April 1993. 

3o Jeremiah F. Creedon, interview, 4 May 1993. 

31 Attendance list, “Terminal Configured Vehicle Flight 

Experiments Working Group (FEWG) meeting,” 18 July 

1973 (from personal files of S. Salmirs); Organizational 

chart listing committee attached with Langley Research 

Center Announcement to all organizational units from 

Edgar M. Cortright, Langley Research Center director, 

Assignmentsfor Terminal Configured Vehicle Program, 1 1 

April 1973 (from ATOPS office files). 

” John Warner, Boeing Commercial Airplane Company, 

interview with author, Seattle, Washington, 27 April 

1993; Delmar M. Fadden, Boeing Commercial Airplane 

Company, interview with author, Seattle, Washington, 27 

April 1993; Richard A. Peal, interview, 28 April, 1933; 

Anthony A. Lambregts, Roeing Commercial Airplane 

Company, interview with author, Seattle, Washington, 26 

April 1993; H.W. Withington and Robert Dum, 

interview, 27 April 1993. 

’’ Jeremiah F. Creedon, interviews, 5 May 1993 and 7 

May 1993; Langley Research Center organizational charts; 

Langley Research Center Announcement, Assignmentsfor 

Terminal Configured Vehicle Program, 1 1 April 1973; 

Walsh, interview, 6 April 1993; John Warner, interview, 

27 April 1993; Samuel A. Morello, interview, 8 April 

1393. 

William D. Mace, phone interview with author, 

Minneapolis, Minnesota, 19 May 199.3; Jeremiah F. 

Creedon, interview, 5 April 1993; TSRV 737 flight logs 

(from ATOPS program office files). 

’‘ Jeremiah F. Creedon, interviews, 5 April 1??3, 5 May 

1993 and 7 May 1993: 1,angley Research Center, Tnli/iiml 

Area Prodirrtiviq I.eve1 I11 Plan, May 199.3. 

Chapter 3: Revolution in the Cockpit: 

Computerization and Electronic Flight Displays 

’ Iknjanii ti M . Elso ti, “I>igital ’~echiiology <;ai iiing 

Acceptance,” Aviation Week d. Space TecllrdoXy. 7 

November 1977, 13 1 - 134, and “767 Digital Avionics 

Stress Flexibility,” Aviation Week & Space TechnoloQgy, 4 

September 1978, 18 1-188, and “Analog to Digital Systems 

Switch Seen,” Aviation Week d. Space 7i.c/inoloQ, 2.3 

October 1978, 1 15- 12 1 ; Barry Miller, “Wider Use of 

Digital ‘l’echniques Seen,” Auiation Week & .Space 

7i.chtiofogy. 10 Noveniher 1975, 90-95. 

’ Earl 1.. Wiener and Kcnwick E. Curry. Flig/tt Deck 

A ii torntition: Promises and Probltrns, NASA-’ I ‘M -8 1 200, 

June 1‘180. 

’ Walter R. (;arttier and Larry I,. Jcnney, Diqdiy 
Requirements and Conceptsfor Space Shuttle Recovey and 

Landing, NASA CR- 123 15 1, July 197 1. 

‘ Report of the Department of Transportation Air Trafic 

ControlAdviso y Committee, Vol. 1 (Washington D.C., 

December 1969), 3-6; D.K. Graham, Transport Airplane 

Flight Deck Development Survqr and Analysis: Report and 

Recommendations, NASA CR-145121, January 1977, 9- 

10; John P. Reeder, Robert T. Taylor, and Thomas M. 

Walsh, New Design and Operating Techniquesfor Improved 

Terminal Area Compatibility, SAE Paper 740454, 

(presented to the Society of Automotive Engineers Air 

Transportation Meeting, Dallas, Texas, 30 April - 2 May 

1974); Robert Dunn, Flight Displaysfor the Next 

Generation Aircra$, SAE Paper 760930, (presented at the 

Society of Automotive Engineers Aerospace Engineering 

and Manufacturing Meeting, San Diego, California, 29 

November - 2 December 1976). 

J. Wyall and D. Eastman, Flight Test Demonstration of 

Selected Curved-Segmented Approach Paths Based on 

Microwave Landing System Guidance, AFFDL-TR-76-43, 

January 1976; and D. Eastman, MLS Project Engineer, 

AFFDL FGR: “MLS Simulation Results,” unpublished 

memorandum. 

Peter R. Kurzhals, “New Directions in Civil Avionics,” 

Astronautics &Aeronautics, March 1978, 40. 

’ Duncan McIver and Jack J. Hatfield, “Coming Cockpit 

Avionics,” Astronautics &Aeronautics, March 1978, 54-63; 

Graham, Flight Deck Survey, 8-10; Gartner and Jenney, 

Display Requirementsfor Shuttle; John P. Reeder, “Flight 

Experiments with Electronic Displays Having Predictive 

Information,” (paper, presented at Radio Technical 

Commission for Aeronautics (RTCA) conference, 

Washington, D.C., November 18-19, 1976); Samuel A. 

Morello, Recent Flight Test Results Using an Electronic 

Dicpkzy on the NASA B-737, AGARD-CP-240, August 

1978. 

’ Samuel A. Morello, interview with author, 8 April 1993; 

ATOPS office flight records. 

Reeder, “Experiments with Electronic Displays.” 

lo Lee H. Person, Jr. and George G. Steinmetz, “The 

Integration of Control and Display Concepts For 

Improved Pilot Situational Awareness,” (paper, presented 

at a Flight Safety Foundation seminar, Acapulco, Mexico, 

9 - 12 November 1981); G.G. Steinmetz, L.H. Person and 

S.A. Morello, Have We Overlooked the Pilot? Role in an 

Automated Flight Deck? AIAA Paper No. 8 1-2262, 

(presented in St. Louis, Missouri, November 17-19, 

1981); Wiener and Curry, Flight Deck Automation. 

“ Steinmetz, Person, and Morello, Have We Overlooked 

the Pilot? Role. 

l2 Lee H. Person and Kenneth R. Yenni, interview with 

author, Hampton, Virginia, 7 April 1993. 

l3 A Category I1 landing is one performed with a 100-foot 

ceiling and only a quarter mile of forward visibility. 

George G. Steinmetz, et al., A Piloted-Simulation 

Evaluation of Two Electronic Display Fomzatsfor Approach 

and Landing,” NASA-TN-D-8 183, April 1976; Samuel A. 

Morello, Charles E. box, and George G. Steinmetz, 

Flight-Test Evaluation of Two Electronic Display Formatsfor 

Approach to Landing Under Instrument Conditions, NASATP-1085, December 1977; Reeder, “Flight Experience 

with Electronic Displays,” 1976; Person and Yenni, 

interview, 7 April 1993. 

l5 Although the electronic flight display research went on 

throughout the life of the program, 1978 is considered the 

end of the initial research phase for CRT displays for 

several reasons. In addition to the fact that the basic 

technology had been proven and several technical papers 

were published on the subject, 1978 was the year Boeing 

made the decision to apply the technology into its next 

commercial airplane. 

Lee H. Person, Jr. and Kenneth R. Yenni, “Flying 

NASA’s Terminal Configured Vehicle Against the 

Microwave Landing System,” Society of Experimental Test 

Pilots, TechnicalReview, Vol. 14, No. 2, 1978, 110-123; 

Morello, interview, 8 April 1993; Person and Yenni, 

interview, 7 April 1993. 

l7 John Whitfield, Lockheed L-1011 program manager, 

phone interview with author, 6 October 1993. 

Elson, “Technology Gaining Acceptance,” 13 1-1 34; 

Society of Engineering Test Pilots, Technical Review, Vol. 

14, No. 2, 1978, 124+; John Whitfield, Lockheed L-1011 

program manager and Don Moore, Lockheed L- 10 1 1 

chiefpilot, phone interview with author, 15 June 1993. 

I’ “Airline Experiments Mini-Symposium’’ Held at the 

Hilton “1776” Inn, Williamsburg, Virginia, 24 - 26 

January 1975. Letter of Invitation from John P. Reeder, 

chief, Terminal Configured Vehicle Program, to Mr. J. 

Wylci, Director Flight Technical, Air Canada, with 

schedule of events and partial list of antendees (from 

personal files of S. Salmirs). 

” H. W. Withington, former vice president of engineering 

and Robert Dunn, former chief engineer of systems 

technology for the Boeing Commercial Airplane 

Company, interview with author, Seattle, Washington, 27 

April 1993. 

2’ Delmar Fadden, chief engineer, avionics/flight systems, 

Renton Division, Boeing Commercial Airplane Company, 

interview with author, Seattle, Washington, 27 April 
1993; John Warner, vice president of Boeing Computer 

Services, interview with author, Seattle, Washington, 28 

April 1993; Dunn and Withington, interview with author, 

27 April 1993; Richard A. Peal, director of systems 

engineering, Boeing Commercial Airplane Company, 

interview with author, Seattle, Washington, 28 April 

1993. 

22 This evolution was related to the author in more than 

20 separate interviews with managers at the NASA Langley 

Research Center in Hampton, Virginia and the Boeing 

Commercial Airplane Company in Seattle, Washington. 

23 The prevalent nature of these kinds of concerns about 

new flight deck technology is also supported in Graham, 

Flight Deck Survey. 

Air Transport Association, Flight Systems Integration 

Committee Memorandum No. 77-22, “Report of the 

Thirteenth Meeting of the Committee,” 7-8 September, 

I977 (from personal files of S. Salmirs). 

25 Peal, interview, 28 April 1993; Jerry Moore, Honeywell, 

Inc., phone interview with author, 18 June 1993; David 

Nakamura, Boeing Commercial Airplane Company, 

phone interview with author, 18 June 1993; Arvind J. 

Dandekar, director of international marketing and 

business, Collins Commercial Avionics, phone interview 

with author, 10 June 1993; Fadden, interview, 27 April 

1993; Morello, interview, 8 April 1993. 

”’ Elson, “767 Digital Avionics,” 18 I. 

’7 “ - Coordination Sheet,” on cost of ownership comparison 

of CKT displays and electromechanical instruments, 

Boeing internal document, 1978; Peal, interview, 28 April 

1993; Dandekar, phone interview, I0 June 1993; 

Nakamura, phone intrrvirw, 18 June 1993; Moore, photic 

interview , 18 June 1903. 

’‘ Fadden, interview, 27 April 1993; Bernard Hainline, 

interview with author, Seattle, Washington, 26 April 

1993; Morello, interview, 8 April 1993; Flight manifests 

and records from the ATOPS office, Langley Kesearch 

Center, Hampton, Virginia. 

‘‘I Hainline, interview, 26 April 1993; Peal, interview, 28 

April 199.3; Elson, “767 Digital Avionics,” 18 1 - 188. 

Nl Ihidekar, phone interview, 10 June, 1993; Peal, 

interview, 28 April 1993; I)an Marrinec, Chairman, 

Airlines Electronic l’ngineering Committee, ARINC, 

photic interview with author, 16 June 1993; Moore, 

phone interview, 18 June 1093; Nakamura, phone 

intcrvicw, 18 lune 1093. 

<I ‘ I‘homas s. Kuh ti, 7%~ .structure of%entific Revolutions, 

2nd ed., I:oundations of the Unity of Science Series: Vol. 

2, No. 2 (Chicago: University of Chicago Press, 1970); 

Joel Arthur Barker, Future Edge: Discovering the New 

Airborne 7jl(ilbhzer 

Paradigms of Success (New York: William Morrow & 

Company, 1992). 

32 Warner, interview, 27 April 1993; Fadden, interview, 27 

April 1993; Morello, interview, 8 April 1993. 

33 Elson, “Spaciousness Key to 767 Flight Deck,” Aviation 

Week &Space Technology, 16 April 1979, 57-63; Morello, 

interview, 8 April 1993; Fadden, interview, 27 April 1993. 

34 Several people from the Langley Research Center served 

on this task force, including researchers who had worked 

with the ATOPS program. 

’’ “IFALPA To Boycott Two-Man-Cockpit Aircraft,” 

Aviation Week &Space Technology, 26 March 1979, 32; 

“German Pilot Association Opposes Two-Man Crew” and 

“A1,PA Crew Position,” Aviation Week & Spnre 

Technology, 20 July I98 I, 36; Richard G. O’l,one, “767 

Program Altered for Two-Man Crew,” Aviation Week & 

Space Technology, 7 Ilecember 1981, 26-27. 

’(’ Wiener and Curry. Flight Deck Automation; Steinmetz, 

Person and Morello, Have We Overlooked the Pilot? Role; 

Graham, Flight Deck Survey; Morello, interview, 8 April 

1993; Fadden, interview, 27 April 1993; Warner, 

interview, 27 April 1993, 

” David Hughes, “Glass Cockpit Study Reveals Human 

Factors Problems,” Amation Week & Space 7echnology, 7 

August 1989, 32-36; Hughes, “Pilots, Research Studies 

Give Mixed Keviews to Glass Cockpits,” Atlintion Week & 

Spnce Technoloa, 23 March 1992. 50-5 1. 

Bruce A. Smith, “Flight Management System Adds 

Roles,” Auintioii Week &Space Technology, 16 April 1979, 

64-65, 

Graham, Flight Deck Survey. 

40 Graham, Flight Deck Survey; Morello, interview, 8 April 

1993; Thomas M. Walsh, interview with author, 

Hampton, Virginia, 6 April 1993. 

Fadden, interview, 27 April 199.3; Morello, interview, 8 

April 1993; Walsh, intcrvicw, 6 April 199.3; Hughes, 

“Glass Cockpit Study,” 32-36; Hughes, “Pilots <;ivc 

Mixcd Reviews,” 50-5 1. 

Morello, interview, 8 April 1993. 

’) Walsh, interview, 6 April 1903; Morello, interview, 8 

April 1993; Breck W. Hcndcrson. “NASA Amcs l’ushcs 

AU to ma t io ti ’ I’oward H ti ma ti- (:c ti tc red 1 ksign, ” aid 

kldward H. l’hillips, “Pilots, Huin:un I;actors Specinlists 

U rge Rcttcr Man-Machi ne (hckpit I iiterf:ice,” Avi/rtioir 

Week & Spncc. T(dinology, 2.3 March 1992, 67-70. 

’+’ NTSR accident records, 1982-1 993; Hughes, “Glass 

Cockpit Study,” 32-36. 
45 H.W. Withington, vice president - engineering, Boeing 

Commercial Airplane Company, letter to Mr. John P. 

Reeder, Chief, Terminal Configured Vehicle Program 

Ofice, NASA Langley Research Center, 6 June 1979. 

Chapter 4: A Technology Eclipsed: 

The Microwave Landing System and the Dawn of GPS 

Performed by a DC-3. John P. Reeder, “NASA-JMLSTRSB Flight Demonstration,” (presentation viewgraphs, 

Montreal, Canada March/April 1978, from ATOPS office 

files). 

’ Department of Transportation and National 

Aeronautics and Space Administration, Civil Aviation 

Research and Development Policy Study, DOT TST- 10-4, 

NASA SP-265, (Washington, D.C., March, 1971). 

Jack Reeder, Proposal for Systems Research Approach to 

Integrating Vehicle-Instrument-Display-Pilot Capability for 

Total Flight Missions, draft, 1969, annotated with 

additional personal notes, 1971; “Report of Department 

of Transportation Air Traffic Control Advisory 

Committee, Vol. 1,” December 1969 (from Federal 

Aviation Administration history records). 

By the 1990s, the organization was called only “RTCA, 

Inc.” The full title was dropped. 

Philip J. Klass, “Future Landing Aid Needs Study 

Launched,” Aviation Week &Space Technology, 1 1 March 

1968, 3 1-32; Time Reference Scanning Beam Microwave 

Landing System, Department of Transportation/Federal 

Aviation Administration public information publication, 

1977, 5. 

‘ Memo with attachments from John P. Reeder, chief, 

Terminal Configured Vehicle Program Office, to 

distribution, regarding MLS flight demonstrations in 

Montreal, Canada, 4 April 1978 (from ATOPS office 

fiies); Time Rejbence Scanning Beam, 5. 

’ Frank L. Frisbie, Former FAA microwave landing system 

program office manager, interview with author, 

Washington, D.C., 13 April, 1993; Vincent L. 

Bencivenga, senior electronic enginecr, microwave landing 

system program ofice staff, FAA, interview with author, 

Washington, D.C., 12 April 1993; Philip J. Klass, 

“Scanning Beam MLS Seen U.S. Choice,” Aviation Week 

&Space Technology, 6 January 1975, 47-49; Time 

Reference Scanning Beam, 5. 

Time Reference Scanning Beam, 6-10; Thomas M. Walsh, 

Samuel A. Morello, and John P. Reeder, “Review of 

Operational Aspects of Initial Experiments Utilizing the 

U.S. MLS,” SP-416, (paper, presented at Aircraft Safety 

and Operating Problems Conference, 18 - 20 October 

1976), 9. 

Frisbie, interview, 13 April 1993; International 

Microwave Landing System Symposium Program, 30 

November - 4 December 1973 (from private files of S. 

Salmirs). 

Io The FAA had installed MLS systems at Wallops Island 

and at the FAA National Aviation Flight Evaluation 

Center (NAFEC) in Atlantic City, New Jersey for 

development and evaluation purposes. 

I’ Thomas M. Walsh, interview with author, Hampton, 

Virginia, 6 April 1993; William F. White, former 

researcher, Flight Instrument Division, Langley Research 

Center, interview with author, Washington, D.C., 13 

April 1993. 

Walsh, interview, 6 April 1993; ATOPS office 

photograph files, Langley Research Center. 

I3 John P. Reeder memo to staff, 7 March 1975 (from the 

personal files of B. White). 

I4 Meeting notes, including outline of effects of MLS 

demonstration on TCV program projects, (from personal 

files of S. Salmirs); Thomas M. Walsh, “Terminal 

Configured Vehicle Program Research Having Potential 

for Fuel Savings,” (paper, presented at the Flight 

International Conference on Fuel Economy in the 

Airlines, Royal Aeronautical Society, London, England, 1 - 

2 April 1980, 6; White, interview, 13 April 1993; Frisbie, 

interview, 13 April 1993; Walsh, Morello, and Reeder, 

“Review of Initial Experiments,” 9. 

l5 

7; William F. White, comp., Flight Demonstrations of 

Curved, Descending Approaches and Automatic Landings 

Using Time Reference Scanning Beam Guidance, NASATM-78745, May 1978,35-36; Hueschen, interview, 4 

May 1993; Bencivenga, interview, 12 April 1993. 

Walsh, “Research Having Potential for Fuel Savings,” 

’‘ Walsh, Morello, and Reeder, “Review of Experiments 

Utilizing the MLS,” 1 1 - 13; White, comp. Flight 

Demonstrations ofApproaches and Landings, 1, 3; also, 

Charles W. Meissner, Jr., “System Description,” in White, 

comp. ,Flight Demonstrations ofApproaches and Landings, 

47-50; Walsh, “Research Having Potential for Fuel 

Savings,” 8; Hueschen, interview, 4 May 1933. 

” Mcrriorandum to TCV program office staff, from 

James E. Stitt, director for Electronics, 24 May 1976, 

acknowledging staff effort for demonstration. 

’’ Richard M. Hueschen, interview with author, 

Hampton, Virginia, 4 May 1993; Walsh, interview, 6 

April 1993; White, comp., Flight Demonstrations of 

Approaches and Landings, 1 ; ATOPS office flight records. 

I” Thomas M. Walsh, interview with author, Hampton, 

Virginia: 4 May 1993; Hueschen, interview, 4 May 1993; 

Delmar Fadden, Boeing Commercial Airplane Company, 

interview with author, Seattle, Washington, 27 April 
1993; Wes Easley and David Holmes, interview with 

author, Hampton, Virginia, 9 April 1993. 

’O Walsh, Morello, and Reeder, “Review of Experiments 

Utilizing the MLS,” 10, 14, 15, 18; White, comp., Flight 

Demonstrations ofApproaches and Landings, 1-2, 36, 39. 

Walsh, Morello, and Reeder, “Review of Experiments 

Utilizing the MLS,” 16; Walsh, “Research Having 

Potential for Fuel Savings,” 11; Bencivenga, interview, 12 

April 1993. 

22 Walsh, Morello, and Reeder, “Review of Experiments 

Utilizing the MLS,” 17; Walsh, “Research Having 

Potential for Fuel Savings,” 12; ATOPS office flight 

records; Hueschen, interview, 4 May 1993. 

23 The progression of the US.-British MLS controversy 

was covered in: Philip J. Klass, “Competing MLS 

Techniques Scrutinized,” Aviation Week &Space 

Tecbnology, 9 August 1976,48-51; Klass, “MLS Faces Key 

Decision in Montreal,” Aviation Week &Space Technology, 

10 January 1977, 19-21; Kenneth J. Stein, “U.S.- 

Sponsored MLS Tested at Kennedy,” Aviation Week & 

Space Technology, 12 December 1977, 34-35; Klass, 

“Landing System Battle Detailed,” Aviation Week & Space 

Technology, 13 February 1978, 12-14; Klass, “Landing 

System Hearings Spur Charges,” Aviation Week &Space 

Technology, 20 February, 1978, 65-72; Klass, ‘“Secrecy’ 

Issue Aired at MLS Hearings,” Aviation Week & Space 

Technology, 27 February 1978, 54-55; Kenneth J. Stein, 

“British Test Landing System in U.S.,” Aviation Week & 

Space Technology, 27 March 1978, 29-30; Frisbie, 

interview, 13 April 1993; Bencivenga, interview, 12 April 

1993. 

’* Letter from G.T. Connors to John P. Reeder, with 

“Supplemental Agreement No. DOT-FA77WAI-883 to 

memorandum of Agreement of May 3, 1973,” outlining 

the MLS demonstration work requested by the FAA, dated 

29 November 1977 (from ATOPS office files); Walsh, 

“Research Having Potential for Fuel Savings,” 7. 

25 John P. Reeder, “NASA-MLS-TRSB Flight 

Demonstrations,” (presentation notes, December 1977, 

from ATOPS office files). 

’‘I Walsh, “Research Having Potential for Fuel Savings,” 

9; John P. Reeder, Robert A. Schmitz, and Leonard V. 

Clark, Opevational Benefits from the Terminal Configured 

Vebicle, NASA-TM-80046, 15-17. 

27 

18; Walsh, “Research Having Potential for Fuel Savings,” 

9- 10. 

Reeder, Schmitz, and Clark, Operational Benefits, 17- 

2‘) Lee H. Person, Jr. and Kenneth R. Yenni, “Flying 

NASA’s Terminal Configured Vehicle Against the 

Microwave Landing System,” Society of Experimental Test 

Pilots, Technical Review, Vol. 14, No. 2, 1978, 113; 

Walsh, “Research Having Potential for Fuel Savings,” 9- 

10; Reeder, Schmitz, and Clark, Operational Benefits, 17- 

19. 

3o Walsh, “Research Having Potential for Fuel Savings,” 

10-1 1. 

31 Frisbie, interview, 13 April 1993; Bencivenga, 

interview, 13 April 1993; Hueschen, interview, 4 May 

1993. 

” Reeder, Schmitz, and Clark, Operational Benefts, 12, 

20. 

’’ Walsh, interview, 6 April 1993. 

j4 Bencivenga, interview, 12 April 1993; Frisbie, 

interview, 13 April 1993; James T. McKenna, “FAA’s 

Assertions of MLS Benefits Fail to Sway Airline 

Operations Personnel,” Aviation Week & Space Technology, 

1 August 1988, 86-87; “U.S. Airlines Reassess Position 

Against MLS,” Aviation Week &Space Technology, 19 

September 1988, 122. 

’’ Frisbie, interview, 13 April 1993; Dr. Jeremiah 

Creedon, interview with author, Hampton, Virginia, 5 

April 1993; Walsh, interview, 6 April 1993; “FAA 

Schedules Briefings On Deployment of MLS,” Aviation 

Week & Space Technology, 1 December 1980, 3 1 ; Paul 

Proctor, “Flight Departments Kequest Revised MLS 

Installation List,” Aviation Week & Space Technology, 12 

May 1986, 77-78; “FAA Continues to Support MLS 

Installation Plan,” Aviation Week & Space Technology, 13 

October 1986, 47; Kenneth J. Stein, “FAA Initiates TwoPhase Effort To Speed Acceptance of MLS,” Aviation 

Week &Space Technology, 23 March 1987, 36-38; Philip J. 

Klass, “Cost and Schedule Questions Threaten MLS 

Installation,” Aviation Week &LYpace Technology, 4 January 

1988,68-69. 

3h James K. Gordon, “FAA Projects Nine-Month Delay in 

Production MLS Deliveries,” Aviation Week &Space 

Technology, 25 March 1985, 32-33; Klass, “Cost 

Questions Threaten MLS,” 68; James T. McKenna, “ATA 

Will Establish Task Force To Critique MLS Programs,” 

Aviation Week &Space Technology, 6 March 1989, 68: 

Philip J. Klass, “FAA Alters Microwave Landing System 

Deployment Plan to Ease ILS Transition,” Aviation Week 

&Space TechnologJ, 8 January 1990. 31; Bencivenga, 

interview, 12 April 1993; Frisbie, interview, 13 April 

1993. 

’’ 

Jeremiah Creedon, interview with author, Hampton, 

Virginia, 7 May 1393. 

Easley and Holmes, interview, 9 April 1993; Dr. .’7 “MLS Transition Undergoes Scrutiny,” Aviation Week 

&Space Technology, 18 April 1988, 86; Philip J. Klass, 

“GAO Recommends Postponing MLS Purchases Until 

Airborne Trailblazer 
Benefits Are Clear,” Aviation Week &Space Technology, 13 

June 1988, 23; Philip J. Klass, “Airlines Back Microwave 

System to Replace Some ILS,” Aviation Week &Space 

Technology, 2 December 199 1,26. 

38 RTCA Tak Force Report on the Global Navigation 

Satellite System (GNSS) Transition and Implementation 

Strategy, (Washington, D.C.: RTCA, Inc., September 

1992), 1. 

39 Bruce D. Nordwall, “GPS Applications, Production 

Grow as System Gains Acceptance,” Aviation Week & 

Space Technology, 31 October 1988, 83-84; Hueschen, 

interview, 4 May 1993. 

*’ Hueschen, interview, 4 May 1993; Philip J. Klass, 

“MLS Simulations Show Curved Approaches Can Boost 

Traffic Flow,” Aviation Week & Space Technohgy, 20 

August 1990, 94; Poritsky, interview, 13 April 1993; 

Creedon, interview, 7 May 1993; Philip J. Klass, 

“Integrated GPS/MLS System Could Be Usefd for 

Terminal Area Operations,” Aviation Week & Space 

Technology, 18 February 1991, 57. 

4’ Hueschen, interview, 4 May 1993; Cary R. Spitzer, 

interview with author, Hampton, Virginia, 13 May 1993. 

42 Creedon, interview, 5 April 1993. 

43 Hueschen, interview, 4 May 1993, and phone 

interview with author, 29 June 1993; Spitzer, interview, 

13 May 1993; Creedon, interview, 7 May 1993; Richard 

M. Hueschen and Cary R. Spitzer, ‘‘Analysis of DGPS/ 

INS and MLS/INS Final Approach Navigation Errors and 

Control Performance Data,” (paper, presented at ION 

conference, San Diego, California, 27-29 January 1992), 

6-11. 

44 Creedon, interviews, 5 April 1993 and 7 May 1993; 

Hueschen. interview. 4 May 1993. 

45 Hueschen, interview, 4 May 1993. 

46 Bencivenga, interview, 12 April 1993; David Hughes, 

“ICAO Delegates Back FANS Concept, Set Stage for 

Global Satellite Systems,” Aviation Week &Space 

Technology, 14 October 1991, 36, 43; “Europeans Favor 

Satellite Navigation But Raise Concerns About GPS’ 

Reliability,” Aviation Week & Space Technology, 6 April 

1992, 60. 

47 Special Committee on Future Air Navigation Systems, 4th 

Meeting, report, ICAO Document 9524,2-20 May 1988. 

4R “ICAO Remains Dubious About GNSS Role,” Flight 

International, 3 1 March - 6 April 1993, 6; “1995 Set For 

FAA GNSS Decision,” Flight International, 31 March - 6 

April 1993, 5. 

*’ “BA Drives to Retain MLS as Main System,” Flight 

International, 3 1 March - 6 April 1993,6; “Final 

Approach,” Flkht International, 3 1 March - 6 April 1993, 

34-36 

50 Bencivenga, interview, 12 April 1993; Hueschen, 

interview, 4 May 1993; Walsh, interview, 6 April 1993; 

Siegbert Poritsky, interview with author, Washington, 

D.C., 13 April 1993; Philip J. Klass, “FAA Steps Up 

Program to Introduce GPS as Instrument Approach Aid,” 

Aviation Week &Space Technology, 17 August 1992, 35- 

36. 

Chapter 5: “The Best That We Can DO” 

Taming the Microburst Windshear 

’ AAC/ARTS Evaluation of NASA Wind Shear Program, 

1992, document from files of Roland Bowles, manager, 

NASA Wind Shear Program. 

Low Altitude Wind Shear and Its Hazard to Aviation, 

Report of the Committee on Low-Altitude Wind Shear 

and Its Hazard to Aviation, (Washington: National 

Academy Press, 1983), 14-15; Roland L. Bowles, 

“Windshear Detection and Avoidance: Airborne Systems 

Survey,” IEEE, (Proceedings of the 29th Conference on 

Decision and Control, Honolulu Hawaii, December 

1990), 708; Michael S. Lewis, et al., “Design and Conduct 

of a Windshear Detection Flight Experiment,” AM 

Paper 92-4092, 1992,2. 

James Ott, “Inquiry Focuses on Wind Shear As Cause 

of Delta L-1011 Crash,” Aviation Week &Space 

Technology, 12 August 1985, 16-19; “Delta Accident 

Report Focuses On Mind Shear Research,” reprint of 

NTSB accident report on the 2 August 1985 Delta Flight 

191 crash, part 4, Aviation Week &Space Technology, 24 

November 1986, 73-75; “Safety Board Analyzes Responses 

to Weather Data,” reprint of NTSB accident report on the 

2 Aiipsr 1985 Delta Flight 191 crash. part 7. Aviotinn 

Week &Space Technology, 15 December 1986, 103-107. 

Low-Altitude Wind Shear, ix, 1 ; Eugene Kozicharow, 

“NTSB Cites Wind Shear In New Orleans Accident,” 

Aviation Week &Space Technology, 28 March, 1983, 32. 

William H. Gregory, “Too Little and Too Late,” 

editorial, Aviation Week & Space Technology, 12 August 

1985, 11; Herbert J. Coleman, “Administration Criticized 

for Delay In Wind Shear Research, Terminal Radar Buy,” 

Aviation Week & Space Technology, 23 September 1985, 

29; “Engen Defends Air Transport System in Senate 

Testimony,” Aviation Week &Space Technology, 7 October 

1985, 30; A. Gary Price, interview with author, 

Hampton, Virginia, 13 May 1993; Roland L. Bowles, 

manager, Wind Shear Program Office, interview with 

author, Hampton, Virginia, 12 May 1993. 

Low-Altitude Wind Shear, 11-12, 14-16. 
T. Theodore Fujita, “Spearhead Echo and Downburst 

Near the Approach End of a John F. Kennedy Airport 

Runway, New York City,” Satellite and Mesometeorology 

Research Project, SMRP Paper 137, University of 

Chicago, March 1976; Low-Altitude Windshear, 11-12, 

20-2 1. 

* Viewgraphs and public information on microburst wind 

shear from NASA Wind Shear Program Office files; LowAltitude Wind Shear, 19-32. 

’ Low Altitude Wind Shear, 33-37; “Wind-Shear 

Detection Technology Examined in 727 Accident Report, 

reprint of NTSB report on the 31 May 1984 United 

Airlines Flight 663 accident, part 4, Aviation Week & 

Space 7echnology, 7 October 1985, 89-91. NTSB Report 

reprint, “Delta Accident Report,” 73. 

lo Low Altitude Wind Shear, 16-18. 

‘I 

Detection,” 719. 

Bowles, interview, 12 May 1993; Bowles, “Windshear 

I’ 

Detection,” 710. 

Low-Altitude Wind Shear, I ; Bowles, “Windshear 

Aerospace Technology Conference and Exposition, Long 

Beach, California, 13-16 October 1986). 

21 Hay, “Overview of Integrated Program,” 62-64. 

22 Bowles, interview, 12 May 1993; “Memorandum of 

Agreement Between Federal Aviation Administration 

(FAA) and National Aeronautics and Space 

Administration (NASA) Concerning Airborne Windshear 

Detection and Avoidance Program,” DTFA01-86-2- 

02018, 24 July 1986, (from ATOPS office files). 

l3 Michael S. Lewis, deputy manager, NASA wind shear 

program office, interview with author, Hampton, Virginia, 

7 May 1993; Bowles, interview, 12 May 1993; Bowles, 

“Windshear Detection,” 708. 

” FAA, “Airborne Windshear Equipment” NPRM, 

20564-20565, 20570; “Airborne Infrared System Provides 

Advance Warning of ’Turbulence,” Aviation Week &Space 

Technology, 19 June 1989, 130; Hay, interview, 13 July 

1993; Bowles, interview, 12 May 1993; 

‘5 Low-Altitude Wind Shear,” 1 

’” Kozicharow, “NTSB Cites Wind Shear,” 32. 

I’ Kozicharow, “NTSB Cites Wind Shear,’’ 32. 

” Bowles, “Windshear Detection,” 710. 

Low-Altitude Wind Shear, ix; “Wind Shear Study,” 

Aviation Week & Space Technology, 28 March 1983, 32. 

Low-Altitude Wind Shear, 1, 81-82. 

I(’ Department of Transportation, Federal Aviation 

Administration, 14 CFR Parts I21 and 135, “Airborne 

Low-Altitude Windshear Equipment and Training 

Requirements; Notice of I’ropoxd Rulemaking,” Federd 

Register. Val 52, No. 104 1 June 1987, Docket No. 191 10; 

Notice No. 79-1 IA, 20564. 

I’ 

Focuses on Wind Shear,” 16; “Safety Board Analyzes 

Responses,” NTSB Report Reprint, 103. 

Bowles, “Windshear Detection,” 7 10; Ott, “Inquiry 

Price, interview, 13 May 1993; Dr. Jeremiah F. 

Creedon, interview with author, Hampton, Virginia, 7 

May 1993; George C. “Cliff‘ Hay, manager, FAA Wind 

Shear program office, phone interview with author, 13 

July 1993; Bowles, interview, 12 May 1993. 

I” “NTSR Recommends Upgraded Training, Reporting 

to Avoid Wind Shear,” reprint of NTSR report on 2 

August 1985 Delta Airlines Flight 1‘) 1 accident, Azktion 

Week &.Spice 7echnol~igy. 2 February 1987, 96; Hay, 

interview, 1.7 July 1993. 

Hay, interview, 13 July 199.3, George C. “Cliff‘ Hay, 

“Overview of the IntcgrLited Federal Aviation 

Administration (FAA) Wind Shear Program Plan,” SAE 

Technical Paper 861 702, (paper, presented at the 

?” Bowles, interview, 12 May 1993; Bowles, “Windshear 

Detection,” 724. 

‘‘I 

May 1993; Bowles, “Windshear Detection,” 7 12-7 15, 

724; “‘F-Factor’ to Warn Pilots of Wind Shear Severity,” 

Aviation Week &Space Technology, 7 September 1992, 

147. 

Bowles, interview, 12 May 1993; I.ewis, interview, 7 

10 Bowles, “Windshear Detection,” 71 1. 

’I 

reprint, 103. 

“Safety Board Analyzes Responses,” NTSR report 

’? Low-Altitude Wind Siiear, 44-45. 

” “Memorandum of Agreement,” 24 July 1986. 

’” Information on all three forward-looking candidate 

systems was gathered from: Low-Altitude Wind Shear, 43- 

46; Bowles, “Windshear Detection,” 7 16-724; Bowles, 

interview, 12 May 1993; Lewis, interview, 7 May 1993; 

Nasa Facts 176, “Making the Skies Safe From Windshear, 

JUII~ I 992; Viewgraphs from the wind shear program 

office files, I .angley liesearch Center. 

Ixwis, et al., “Design and (:onduct of an F,xpcrinient,” 

3; William R. Scott, “NASA Flies 737 Through 

Microhursts in Wind Shcar Flight Research Effort,” 

Aviation Week & Spnce ’Iechnology, 16123 December 199 1, 

46; Bowles, interview, 12 May 1993; Lewis, interview, 7 

‘34 Airborne Trailbhzer 
May 1993. 

36 Bowles, “Windshear Detection,” 719. 

37 Lewis, et al., “Design and Conduct of an Experiment,” 

3. 

38 Memorandum of Agreement, “For Airborne Windshear 

Advanced Technology Operational Program,” FAAl 

NASA Interagency Agreement No. DTFAO1-90-2-02021, 

31 May 1990. 

39 Lewis, et al., “Design and Conduct of an Experiment,” 

4-6. 

40 Lewis, interview, 7 May 1993. 

41 Lewis et al., “Design and Conduct of an Experiment,” 

4-6; Lewis, interview, 7 May 1993; Michael S. Lewis, 

phone interview with author, 15 July 1993; Viewgraphs 

from NASA Wind Shear Program Office files. 

42 Lewis, et al., “Design and Conduct of an Experiment,” 

3, 6-8; Lewis, interview, 7 May 1993; Lee H. Person, 

interview with author, Hampton, Virginia, 14 May 1993; 

Scott, “NASA 737 Flies Through Microbursts,” 46-47; 

video footage and photographic records of 1991 Orlando 

and Denver flight tests, from NASA Wind Shear Program 

Office files. 

‘’ Creedon, interview, 7 May 1993; Bowles, interview, 12 

May 1993; 

44 Artie D. Jessup, phone interview with author, 16 July 

1993; Creedon, interview, 7 May 1993; Bowles, interview, 

12 May 1993. 

45 Bruce D. Nordwall, “Modified Doppler Detects Wind 

Shear More Reliably,” Aviation Week & Space 

Technology, 7 September 1992, 143-1 5 1; Michael 

Finneran, “Burst-Busters,” NASA Magazine, Winter 1993, 

18-22; Bowles, interview, 12 May 1993; Lewis, interview, 

7 May 1993; Creedon, interview, 7 May 1993. 

46 Michael S. Lewis, phone interview with author, 16 July 

1993; Bowles, interview, 12 May 1993; Hay, interview, 13 

July 1993; Lewis, interview, 7 May 1993; Philip J. Klass, 

“New Airborne Radar Shows Promise of Detecting 

Dangerous Microbursts,” Aviation Week & Space 

Technology, 10 February 1992,44-45; Nordwall, 

“Modified Doppler,” 143- 1 5 1. 

47 

Program, 1992. 

AAClARTS Evaluation of NASA Wind Shear 

4x Creedon, interview, 7 May 1993. 

Chapter 6: Improving Aircraft Systems 

‘ 

Research Center, 1 December 1973, 1-3; “Advanced 

“Terminal Configured Vehicle Program Plan,” Langley 

Transport Operating Systems Program Review,” Langley 

Research Center, 20 October 1982 (presentation 

viewgraphs, from Flight Systems Directorate office files). 

David C.E. Holmes and Wes C. Easley, interview with 

author, Hampton, Virginia, 9 April 1993; more detailed 

information on DATAC operation can be found in: David 

C.E. Holmes, “Global System Data Bus Using the Digital 

Autonomous Terminal Access Communication Protocol,” 

(paper, presented at the IEEE/AIAA 7th Digital Avionics 

Systems Conference and Technical Display, Fort Worth, 

Texas, 13-16 October 1986; Also in: W.C. Easley and J.S. 

Tanguy, “Interface of the Transport Systems Research 

Vehicle Monochrome Display System to the Digital 

Autonomous Terminal Access Communication Data Bus,” 

NASA TM 87728, May 1986. 

Holmes and Easley, interview, 9 April 1993; William E. 

Howell, interview with author, Hampton, Virginia, 6 

April 1993. 

Holmes and Easley, interview, 9 April 1993. 

Howell, interview, 6 April 1993; Boeing demonstration 

conducted 16 September 1985 (from B-737 flight records 

in ATOPS program office files); Simone Pottenger, Boeing 

Commercial Airplane Company, phone interview with 

author, 22 July 1993. 

‘ Holmes and Easley, interview, 9 April 1993; Daniel 

Martinec, Airlines Electronic Engineering Committee, 

Aeronautical Radio, Inc., phone interview with author, 22 

July 1993. 

’ Artie D. Jessup and Cay R. Spitzer, interview with 

author, Hampton, Virginia, 7 May 1993. 

* James R. Kelly, Lee H. Person, and Kevin R. Bruce, 

“Flight Testing TECS - The Total Energy Control 

System,” SAE TP-861803 (presented at the Aerospace 

Technology Conference and Exposition, Long Beach, 

California, 13-16 October 1986; James R. Kelly, interview 

with author, Hampton, Virginia, 5 May 1993; Anthony 

A. Lambregts, Boeing Commercial Airplane Company, 

interview with author, Seattle, Washington, 26 April 

1993; Delmar Fadden, chief engineer, avionicdflight 

systems, Renton Division, Boeing Commercial Airplane 

Company, interview with author, Seattle, Washington, 27 

April 1993; Lee H. Person, interview with author, 

Hampton, Virginia, 14 May 1993; TSKV B-737 flight 

logs, from ATOPS office files. 

’ Terence S. Abbott, interview with author, Hampton, 

Virginia, 14 May 1993; Terence S. Abbott, “TaskOriented Display Design: Concept and Example,” SAE 

Technical Paper 892230, (presented at Aerospace 

Technology Conference and Exposition, Anaheim, 

California, 25-28 September 1989. 

’” D.L. Mahaffey, Richard L. Horst, and Robert C. 
Munson, “Behavioral Comparison of the Efficacy of Bar 

Graphs and Polar Graphics for Displays of System Status,” 

Proceedings of the 1986 IEEE International Conference on 

Systems, Man and Cybernetics, IEEE Catalog No. 

86CH2364-8, Institute of Electrical and Electronics 

Engineers, Inc., 1986, 15 14-1 5 19; Robert C. Munson 

and Richard L. Horst, “Evidence for Global Processing of 

Complex Visual Displays,” Proceedings of the Human 

Factors Socieg 30th Annual Meeting, Vol. 2, Human 

Factors Society, Inc., 1986, 776-780. 

’I Terence S. Abbott, “A Simulation Evaluation of the 

Engine Monitoring and Control System Display,” NASA 

TP-2960, February 1990; Abbott, interview, 14 May 

1993. 

Robert H. Kinder, General Manager, Engineering 

Technology and Advanced Aircraft Programs, McDonnell 

Douglas Corporation letter to Dr. J.F. Creedon, NASA 

Langley Research Center, 15 August 1991. 

I’ Abbott, interview with author, 14 May 1993; Robert 

Brooks, ARNAV Systems, Inc., phone interview with 

author, 22 July 1993. 

Thomas S. Kuhn, The Structure of Scientifc Revolutions, 

2nd ed., Foundations of the Unity of Science Series: Vol. 

2, No. 2, (Chicago: University of Chicago Press, 1970); 

Joel Arthur Barker, Future Edge: Discovering the New 

Paradigms of Success, (New York: William Morrow & 

Company, Inc., 1992), 55-92. 

Is 

Virginia, 14 May 1993; L)avid R. Middleton, 

Raghavachari Srivatsan, Lee H. Person, “Simulator 

Evaluation of Displays for a Takeoff Performancc 

Monitoring System,” NASA TP-2908, May 1989; James 

’I. McKennd, “NASA Develops System to Monitor 

Aircraft Performance on Takeoff,” Aviation Week & Spnce 

7>cbnoloRy, 13 November 1989, 43-50. 

David B. Middleton, intcrview with author, Hanipton, 

I‘ 

Person, “Simulator Evaluation of Displays for a Revised 

Takeoff Performancc Monitoring System,” NASA TP3270, Deccniber 1992, 1. 

David R. Middleton, Raghavachari Srivatsan, Lee H. 

I’ Middleton, interview, I4 May 1993; NASA 5 15 

Vehicle flight records, ATOPS program office files. 

’‘ Middleton, interview, 14 May 1993; Richard A. Peal, 

director of systems engineering, Roeing Commercial 

Airplane Company, interview with author, Seattle, 

Washington, 28 April 1993. 

I” Middleton, interview, 14 May 1993. 

”I Fadden, interview. 37 April 1993. 

‘I Dr. Jeremiah F. Creedon, interview with author, 

Hampton, Virginia, 5 April 1993. 

Airborne Trdbhzer 

22 Stephanie, Public Affairs, Everett Division, Boeing 

Commercial Airplane Company, phone interview with 

author, 20 July 1993. 

23 Kinder to Creedon, letter, 15 August 1991 

Chapter 7: Improving Aircraft Operations 

’ LFM was not the same thing as a “slot time,” which 

assigned each inbound aircraft a specific, reserved arrival 

time. LFM matched the number of arrivals with the 

actual, real-time capabilities of the airport. This number 

often differed from the slot time reservations, due to delays 

or poor weather conditions. 

Charles E. Knox, interviews with author, Hampton, 

Virginia, 7 April 1993 and 7 May 1993; Charles E. Knox, 

“Denver Local Flow Management Flight Tests,” summary 

with viewgraph, 11 October 1979 (from ATOPS office 

files); John P. Reeder, “Participation in Flight Tests at 

Denver Stapleton Airport,” memo with attachments, to 

distribution, 20 August 1979 (from ATOPS office files). 

box, “Denver Flight Tests,” 11 October 1979; Charles 

E. Knox and Dennis G. Cannon, “Development and Test 

Results of a Flight Management Algorithm for FuelConservative Descents in a Time-Based Metered Traffic 

Environment,” NASA-TP-1717, October 1980, 1-2, 25- 

31; Knox, interviews, 7 April 1993,7 May 1993, and 13 

May 1993. 

“Comments From Onboard Observers, TCV Denver 

Time-Rased Metering/Local Flow Management Flight 

Tests, June 19 through June 28, 1979,” typed summary, 

(from ATOPS officc files); Ralph Kiss, Chief, Denver 

ARE, “NASA TCV Flight Tests With Denver ARTC,” 

with additional comments on NASA/Denvrr ARTCC 

Time-Based Metering and Agenda Item Responses, 

undated typed report (from ATOPS office files). 

Knox, interview, 13 May 1993; John Whitfield, 

Lockheed L-1011 program manager and Don Moore, 

Lockheed L-1011 chief pilot, phone interview with 

author, 15 June 1993; Boeing Commercial Airplane 

Company press materials on aircraft production, flight and 

delivery dates. 

‘’ Charles E. Knox, “Flight Planning For TimeConstrained/Fuel Efficient Descents,” typed summary 

report of research experiments, 9 September 1981 (from 

ATOPS office files); Charles E. Knox, “Planning FuelConscrvativc Descents With or Without Time Constraints 

Using a Small Programmable Calculator,” NASA TP2085, February 1983; C.E. Knox, D.D. Vicroy and D.A. 

Sininion, “Planning Fuel-Conservative Ilesccnts in an 

Airline Fmvirontncnt Using x Small Progranimnble 

Calculator,” NASA ’1’P-2393, May 1985; Knox, intervicw, 

13 May 1993. 

’ Knox, interview, 7 May 1993. 
’ “767 FMCS - Initial 4D Guidance Alternatives,” 767 

Study Engineering Work Authorization, SEWA No. 39, 

undated, referencing United Airlines Letter, J. Goodwine 

to F. Copes Van Hesselt, “B-767 Flight Management 

System - 4-D Nav,” 6 July 1979 and United Airlines, “4- 

D Navigation Capability,” CRWS No. 34- 189; Knox, 

interview, 13 May 1993; David Allen, Boeing Commercial 

Airplane Company, Everett Division, phone interview 

with author, 2 August 1993. 

Allen, interview, 2 August 1993. 

IO Heinz Erzberger, Thomas J. Davis, Steven Green, 

“Design of Center-Tracon Automation System,” (paper, 

presented at the AGARD Guidance and Control 

Symposium on Machine Intelligence in Air Traffic 

Management, 11-14 May 1993, Berlin, Germany. 

I’ “CTAYTSRV Trajectory Prediction Flight 

Experiment,” Plan of Test No. V92135,2 October 1992 

(from David H. Williams office files); David H. Williams, 

phone interview with author, 4 August 1993. 

” John Garren and John P. Reeder, “Cockpit Display of 

Traffic Information (CDTI), A Perspective,” memo, 

undated (from ATOPS office files). 

l3 D. H. Ewing and R. W. K. Smith, “Teleran-Air 

Navigation and Traffic Control by Means of Television 

and Radar,” RCA Review, Vol VII, No. 4, December 

1946,601-621. 

l4 Mark E. Connelly, “Simulation Studies of Airborne 

Traffic Situation Display Applications, Final Report,” 

Report ESL-R-75 1, May 1977. 

l5 Terence S. Abbott, et al., “Early Flight Test Experience 

With Cockpit Displayed Trafic Information,” NASA 

TM-80221, February 1980; Terence S. Abbott, et al., 

“Flight Investigation of Cockpit-Displayed Traffic 

Information Utilizing Coded Symbology in an Advanced 

Operational Environment,” NASA TP- 1684, 1980; Knox, 

interview, 13 May 1993; David H. Williams, phone 

interview with author, 16 August 1993. 

l6 David H. Williams, phone interviews with author, 4 

August 1993 and 16 August 1993. 

Charles E. Knox and Charles H. Scanlon, “Flight Tests 

Using Data Link for Air Traffic Control and Weather 

Information Exchange,” SAE Paper 901888, SAE 1990 

Transactions, Section 1, Vol. 99, Part 2, 1683. 

hox, interview, 7 May 1993. IR 

l9 Charles E. Knox and Charles H. Scanlon, “Flight Tests 

With a Data Link Used for Air Traffic Control 

Information Exchange,” NASA TP-3 135, Septeniber 

199 1, 1 ; David A Hinton and Gary W. Lohr, “Simulator 

Investigation of Digital Data-Link ATC Communications 

in a Single-Pilot Operation,” NASA TP-2837, December 

1988; Knox, interview, 7 May 1993. 

2o Philip J. Klass, “Predeparture Clearance to Be Sent Via 

Data Link at Major Airports,” AYiation Week e+ Space 

Technology, 25 June 1990,43. 

’’ Knox and Scanlon, “Flight Tests Using Data Link,” 

1684; Marvin C. Waller and Gary W. Lohr, “A Piloted 

Simulation Study of Data Link ATC Message Exchange,” 

NASA TP-2859, February 1989; Knox, interview, 7 May 

1993. 

22 Knox and Scanlon, “Flight Tests Using Data Link,” 

1683-1684. 

23 Knox and Scanlon, “Flight Tests With a Data Link;” 

Knox, interviews, 7 April 1993,7 May 1993; Edward H. 

Phillips, “Langley Data Link System Provides ATC 

Communications, Weather Depiction,” Aviation Week & 

Space Technology, 6 January 1992, 52-53. 

24 Knox, interview 7 May 1993; TSRV 737 flight log 

records from ATOPS office files. 

25 Knox and Scanlon, “Flight Tests Using Data Link,” 

1692. 

Knox, interview, 13 May 1993; Allen, interview, 2 

August 1993. 

27 David H. Williams and Steven M. Green, “Piloted 

Simulation of an Air-Ground Profile Negotiation Process 

in a Time-Based Air Trafic Control Environment,” 

NASA TM-107748; Williams, interview, 4 August 1993. 

28 Hugh McLaurin, Federal Aviation Administration, 

phone interview with author, 2 August 1993. Note: a 

transponder is a transmitter in an airplane that sends out a 

coded signal to air traffic controllers to help them locate 

the position of aircraft on their radar scopes. Mode “A 

transponders report only a selectable numerical code and 

the lateral position of the airplane, while Mode “C” 

transponders report altitude, as well. Mode “S” 

transponders send out a discrete code that applies only to 

that particular aircraft and always remains the same. 

29 box, interview, 7 May 1993. 

30 Allen, interview, 2 August 1993; Barbara Murphy, 

Boeing Commercial Airplane Company, Everett Division, 

phone interview with author, 10 August 1993. 

31 

Promise for Increased Compatibility with an Advanced 

ATC System,” Proceedings, Air Traffic Control 

Association, 22nd Annual Meeting, Law Vegas, Nevada, 

Kenneth E. Hodge, “Aircraft Developments that Hold 

10-13 October 1977, lS5. 

32 Anthony A. Lambregts, Boeing Commercial Airplane 
Company, interview with author, Seattle, Washington, 26 

April 1993. 

Film Cover on the Profile Drag of an Aircraft Wing 

Panel,” NASA TM-74073, October 1977. 

33 Anthony A. Lambregts and Jeremiah F. Creedon, 

“Development and Flight Evaluation of Automatic Flare 

Laws with Improved Touchdown Dispersion,” AIAA 

Paper 80-1757, (printed in collection of papers from the 

AIAA Guidance and Control Conference, Danvers, 

Massachusetts, 1 1-13 August 1980); Lambregts, interview, 

26 April 1993; Jeremiah F. Creedon, interview with 

author, Hampton, Virginia, 7 May 1993. 

34 Lambregts, interview, 26 April 1993; Dwight Schaeffer, 

Boeing Commercial Airplane Company, phone interview 

with author, 2 August 1993. 

.’5 Dr. Jeremiah Creedon, interview with author, 

Hampton, Virginia, 7 May 1993. 

’” W. Thomas Bundick, David B. Middleton, and 

William L. Poole, “Results of Aircraft Open-Loop Tests of 

an Experimental Magnetic Leader Cable System for 

Guidance During Roll-Out and Turnoff,” NASA TM4135, February 1990, 2; A.F. Hammond, “Guidance and 

Control of Aircraft Ground Movement at Airports During 

Restricted Visibility - A survey of Requirements and 

Possible Systems,” Technical Report No. 65071, British 

Royal Aircraft Establishment, March 1965; H.C. Morgan 

and P. England, “A Taxi-Guidance System for Aircraft 

Using a Single Magnetic Leader Cable,” Technical Report 

No. 66065, British Royal Aircraft Establishment, February 

1966. 

’- S. Pines and Richard M. Hueschen, “Guidance and 

Navigation for Automatic Landing, liollout, and Turnoff 

Using MLS and Magnetic Cable Sensors,” Contractor 

Report under Contract No. NASI-1431 1, catalog no. 78- 

1296, 1978. 

jX Bundick, Middleton and I’oole, “Results of Aircraft 

Open-Loop Tests;” W. Thomas Rundick, phone interview 

with author, 19 August 1993. 

’‘I 

August 1993. 

David B. Middleton, phone interview with author, 18 

Chapter 8: A National Facility 

’ John White, Operations Manager, ATOPS program, 

interview with author, Hampton, Virginia, 5 April 1993. 

* Continental Airlines also tested a third coating, called 

Astrocoat, on its 727, but the Astrocoat performance was 

below that of the Chemglaze and the CAAPCO 

substances, and it was not included in the subsequent 

Delta tests or the NASA flight evaluations. 

’ Richard L. Kreitinger and David B. Middleton, 

“Aircraft Surface Coatings for Drag ReductiodErosion 

Protection,” SAE Paper 81 1070, (presented at the 

Aerospace Congress & Exposition, Anaheim, California, 

5-8 October 1981); David B. Middleton, phone interviews 

with author, 23 August 1993 and 26 August 1993. 

‘ A. Bertelrud, R.D. Watson and C.B. McCinley, “Flow 

Measurements on the Fuselage of a Boeing 737 Airplane,” 

AIAA Paper 89-0209, (presented at the 27th Aerospace 

Sciences Meeting, Reno, Nevada, 9-12 January 1989). 

’ Ralph D. Watson, phone interview with author, 27 

August 1993. 

’ Long P. Yip, interview with author, Hampton, Virginia, 

7 May 1993; Edward H. Phillips, “NASA/Langley Using 

Varied Approach to Develop Subsonic High-Lift Devices,” 

Avicltion Week &Spnce Technology, 10 February 1992, 49. 

‘I Long P. Yip, et al., “Subsonic High-Lift Flight Research 

on the NASA Transport Systems Research Vehicle 

(TSRV),” AIAA Paper 92-4103, (presented at the AIAA 

6th Bicnnial Flight Test Conference, Hilton Head, South 

Carolina, 24-26 August 1992); Long P. Yip, et al., “lnFlight Pressure Distributions and Skin-Friction 

Measurements on a Subsonic lransport High-I.ift Wing 

Section,” AGAKLI Conference Proceeding CP-415, Paper 

21 (presented at the Symposium on High-Lift System 

Aerodynamics, Banff, Alberta, Canada, 5-8 October 

1992); Yip, interview, 7 May 1993. 

I” From National Transportation Safety hard accident 

records. 

’I Bill wording as quored in ’l’homas J. Yager, William A. 

Vogler and Paul Haldasare, “Evaluation of ‘Iwo l‘ransport 

Aircraft and Several Ground Test Vehicle Friction 

Measurements Obtained for Various Runway Surface 

Types and Conditions,” NASA T1’-2917, February 1990, 

1. 

’ Richard L. Kreitinger and David B. Middleton, 

“Aircraft Surface Coatings for Ilrag 1ieductiodErosion 

Protection,” SAE Paper 8 1 1070 (presented at the 

Aerospace Congress & Exposition, Anaheim, California, 

5-8 October 1981), 1. 

I? Thomas J. Yager, phone interview with author, 23 

August 1993. 

1 ’ Yagcr, Vogler and I3aldasare, “Friction Me;isurenients,” 

3-1 1, 16-22; Yagcr, interview, 23 August 1993. 

.’ William I). Reasley and Robcrt J. McGhee, “An 

Exploratory Investigation of the Effects of a Thin Plastic 

’I’ Lee H. Person, interview with author, Hanipton, 

Virginia, 14 May 1993. 

Airborne Trailblazer 
Is Yager, interview, 23 August 1993. 

I6 Yager, Vogler, and Baldasare, “Friction Measurements,” 

20-22; Yager, interview, 23 August 1993. 

Kenneth R. Yenni and William E. Howell, “Flight 

Tests of a Helmet-Mounted Display Synthetic Visibility 

System,” NASA Document, apparently unpublished (from 

ATOPS office files); Mark S. Rolwes, McDonnell Douglas 

Corporation, phone interview with author, 22 August 

1993; Mark S. Rolwes, “An Alternative Approach to 

Providing External Vision to Pilots of Future Air 

Vehicles,” IEEE Paper, CH2929-8/90/0000-0540, 1990, 

540-544. 

Rolwes, interview, 22 August 1993; Yenni and Howell, 

“Helmet-Mounted Display,” 2-3; Person, interview, 14 

May 1993; TSRV 737 flight log records (from ATOPS 

office files). 

Rolwes, interview, 22 August 1993. 

’O James Kelly, interview with author, Hampton, 

Virginia, 5 May 1993; James Hall, interview with author, 

Hampton, Virginia, 7 April 1993; Person, interview, 14 

May 1993; “Examples of Advanced Technologies that 

have been Transferred to Industry Applications after Initial 

Flight Test on Langley ATOPS B-737 Aircraft,” ATOPS 

office summary document; TSRV 737 flight log records 

(from ATOPS office files). 

21 Webster’s New Twentieth Century Dictionary of the 

English Language, Unabridged, 2nd ed., (New York: 

Simon & Schuster, 1983), 215. 

22 Charles E. box, interview with author, Hampton, 

Virginia, 13 May 1993; Person, interview, 14 May 1993; 

TSRV 737 flight logs (from ATOPS office files). 

Conclusion 

Hans Mark and Arnole Levine, The Management of 

Research Institutions: A Look at Government Laboratories, 

NASA SP-481, (Washington, D.C., 1984), 265. 

Langley Research Center Mission Statement summary, 

viewgraph, from Flight Systems Directorate files, NASA 

Langley Research Center, 1993. 

Thomas M. Walsh, former deputy chief, TCV/ATOPS 

program, interview with author, Hampton, Virginia, 6 

April 1993. 
Airborne Trailblazpr 
Bibliographic Essay 

he majority of the material for this book T came from five different sources. The 

primary source of information was 60 individual 

interviews with engineers and managers from 

NASA, the Federal Aviation Administration, and 

industry who were involved with NASA's Boeing 

737 or the technology the airplane helped to 

research. Information pertaining to the specific 

research projects conducted with the airplane 

was also obtained from NASA technical reports, 

technical papers, technical memoranda, and 

contractor reports. Some of these technical 

publications were located through the University 

of Minnesota Walter Library, in Minneapolis, 

Minnesota. The remainder were found through 

the Floyd L. Thompson Technical Library at the 

Langley Research Center in Hampton, Virginia, 

or in the Advanced iransport Operating 

Systems (ATOPS) program office, also at 

Langley. 

regard to the early days of the Terminal 

Configured Vehicle (TCV) program, was 

specific correspondence, memos, proposals, and 

notes from the ATOPS office files. The ATOPS 

office files also contained extensive information 

about the 737, including flight logs, passenger 

A third important source, especially with 

manifests, detailed reports of each research flight, 

and summaries of the 737's flight time by year 

and by research project. In addition, several 

managers at NASA and at the Boeing 

Commercial Airplane Company provided copies 

of their personal notes that they had saved since 

the time they had worked with the TCV 

program. Information about congressional 

action related to the program, political forces 

that impacted the airplane's research, and 

material on the history of technology transfer in 

NASA came from the historical archives at 

NASA Headquarters in Washington, D.C. 

The fifth source for the material in this book 

was popular literature and industry publications. 

Aviation Week eb Space Technology, a weekly 

aerospace news magazine, provided good 

background information on relevant 

developments in the aviation industry and the 

incorporation of new technologies into 

commercial products. Valuable information on 

the theories of technology transfer and change 

came from a variety of publicly available books, 

ranging from Thomas S. Kuhn's The Structure of 

Scientzfic Revolutions to Murketing Wa$are by Al 

Ries and Jack Trout. 

Illustration Credits 

Pages Credits Pages Credits 

Cover 

End paper 

iv 

vi 

vi 

vii 

... . VIII-IX 

x- 1 

2-3 

4-5 

6-7 

8-9 

10 

11 

12-13 

14 

15 

16-17 

19 

20 

24 

17 19 bL-LJ 

26 

27 

28 

29 

30 

31 

32 

33 

34 

35 

36 

37 

38-39 

40-4 1 

NASA Art Program, artist John Clark, 

NASA photo number 93-HC-409. 

NASA photo. 

NASA photo. 

Courtesy Boeing Commercial Aircraft 

Corporation Archives. 

Courtesy Boeing Commercial Aircraft 

Corporation Archives. 

Courtesy Boeing Commercial Aircraft 

Corporation Archives. 

NASA photo number L-80-2960. 

(Left) NASA photo number LAL 3412. 

(hght) NASA photo number 

Original art by NASA Langley 

Research Center artist 

William B. Kluge. 

Original art by NASA Langley 

Research Center artist 

William B. Kluge. 

Original art by NASA Langley 

Research Center artist 

William B. Kluge. 

(Left) NASA photo number 88-1 1728 

NASA photo number L-8 1-47 15. 

NASA photo number L-73-5357. 

NASA photo number L-87-10,498. 

Courtesy Boeing Commercial Aircraft 

Corporation Archives. 

NASA photo number L-82-5,226. 

NASA photo number L-87-01078. 

NASA photo number 92-09653. 

NASA photo number L-85-10,992. 

NASA photo number 89- 13,503. 

iynan photo number 76-E-70. 

(Left) NASA photo number L-89-328. 

(Right) NASA photo number 

NASA photo number L-74-7810. 

NASA photo number 1,-74-5 183. 

NASA photo number L-86-2784. 

NASA photo number L-87-3645. 

NASA photo number L-90-8321. 

NASA photo number L-90-13735. 

NASA photo number L-80-287 1. 

NASA photo number L-74-5 187. 

NASA photo number L-75-3195. 

NASA photo number L-86-10,859. 

NASA photo number L-87-9199. 

NASA photo number L-90-8322. 

NASA photo number 92-09978. 

(Left) NASA photo number 92-09637. 

(Right) NASA photo number 

L-76-6225. 

L-89-12410. (Right) 

\TAP1 

WI89-44-3. 

L-87-7703. 

42 

44 

45 

48 

49 

52 

54-55 

56-57 

58 

59 

60 

62 

63 

64 

65 

66 

67 

69 

70 

71 

72 

74-75 

76 

79 

80-8 1 

84 

85 

88 

96-97 

104- 105 

107 

108 

109 

110 

112 

113 

114 

115 

116 

118 

NASA artist's conception. 

NASA photo number L-85-7219. 

NASA photo number L-74-7896. 

NASA photo number. 

NASA photo number L-78-4715. 

NASA photo number 89-6358. 

(Left) NASA photo number 

NASA photo number 92-09647. 

(Left) NASA photo number 91-18889. 

(Right) NASA photo number 

NASA photo. 

NASA photo number 92-09631. 

NASA photo number L-88-89717. 

(Top) NASA photo number 91-01645. 

(Bottom) NASA photo number 

(Top) NASA photo number 91-01645. 

(Bottom) NASA photo number 

L-92-1814. 

NASA photo number 92-09652. 

NASA photo number 92-10002. 

NASA photo number L-92-6965. 

NASA photo number L-92-6965. 

NASA phoro number 92-09629. 

NASA photo number 92-095 10. 

NASA photo number 91-12297. 

NASA photo number 92-12352. 

(Left) NASA photo number L-91- 

15885. (Right) NASA photo number 

NASA photo number L-87-09642. 

NASA photo number 92-10540. 

NASA photo numbers (L-R) L-91- 

i6683, 9i-iG694, and 9i-i6704. 

NASA photo number L-89-11171. 

NASA photo number L-89-11170. 

NASA photo number 92-09988. 

NASA photo numbers (L-R) L-90- 

6326, 90-06592, and 90-06609. 

(Left) NASA photo number 92-10541. 

(Right) NASA photo number 

89-04534. 

NASA photo number L-93-8 172. 

NASA photo number L-92-1805. 

(Top) NASA photo number 

L-85-2995. 

NASA photo number 89-06012. 

NASA photo number 89-03671. 

NASA photo number L-89-4514. 

NASA photo number 89-06014. 

NASA photo number L-76-6226. 

NASA photo number L-92-4166. 

NASA photo number L-83-13502. 

L-92-8374. (Right) 

92-09638. 

L-92-18 14. 

92-10532. 
I44 Airborne Trdblrrzer 

I’ 
Glossary of Acronyms 

ACARS 

ACFS 

ADEDS 

AFD 

AGCS 

ARINC 

ARTCC 

ATA 

ATC 

ATIS 

ATOPS 

AWOP 

CARD 

CDI 

CDTI 

CDU 

c/o 

CRT 

CTAS 

CTOL 

cws 

DATAC 

DME 

DOT 

EADI 

EASILY 

EFSS 

EHSI 

EICAS 

EMACS 

EPR 

FAA 

FID 

FLTCTL 

FMC 

FMS 

GNSS 

GPS 

HDD 

HUD 

ICAO 

IFR 

ARINC Communications Addressing and Reporting System 

Advanced Concepts Flight Simulator 

Advanced Digital Electronic Displays 

Aft Flight Deck 

Automatic Guidance and Control System 

Aeronautical Radio, Inc. 

Air Route Traffic Control Center 

Air Transport Association 

Air Traffic Control 

Automatic Terminal Information Service 

Advanced Transport Operating Systems 

All-Weather Operations Panel (of ICAO) 

Civil Aviation Research and Development (study) 

Course Deviation Indicator 

Cockpit Displayed Traffic Information 

Control and Display Unit 

Check Out 

Cathode Ray Tube 

Center Tracon Automation System 

Conventional Take-Off and Landing (aircraft) 

Control Wheel Steering 

Digital Autonomous Terminal Access Communication (data bus) 

Distance Measuring Equipment 

Department of Transportation 

Electronic Attitude Director Indicator 

Experimental Avionics Simulation and Integration Laboratory 

Experimental Flight Systems Section (at Langley) 

Electronic Horizontal Situation Indicator 

Engine Indication and Crew Advisory System 

Engine Monitoring and Control System 

Engine Pressure Ratio 

Federal Aviation Administration 

Flight Instrumentation Division (at Langley) 

Flight Control 

Flight Management Computer 

Flight Management System 

Global Navigation Satellite System 

Global Positioning System 

Heads-down Display 

Heads-up Display 

International Civil Aviation Organization 

Instrument Flight Rules 

ILS 

INS 

IRU 

JAWS 

LEBU 

LFM/PD 

LIDAR 

LLWAS 

MLS 

NACA 

NAFEC 

NAS 

NASA 

NAS P 

NCAR 

NTSB 

OAS 

OPMIS 

OST 

OSTP 

PFD 

RNAV 

R&D 

RTCA 

SBIR 

SPIFR 

SSFD 

SST 

STEP 

TAP 

TCAS 

TCV 

TDWR 

TECS 

T@PMS 

TRSB 

TSRV 

UHF 

VCWS 

VFR 

VHF 

WFF 

Instrument Landing System 

Inertial Navigation System 

Inertial Reference Unit (same as INS) 

Joint Airport Weather Studies 

Large Eddy Break-Up (devices) 

Local Flow Management/Profile Descent 

Light Detecting and Ranging 

Low Level Windshear Alert System 

Microwave Landing System 

National Advisory Committee for Aeronautics 

National Aviation Facilities Experimental Center 

National Academy of Sciences 

National Aeronautics and Space Administration 

National Aerospace Plane 

National Center for Atmospheric Research 

National Transportation Safety Board 

Organization of American States 

Optical Propulsion Management Interface System 

Ofice of Science and Technology (developed into OS 

Office of Science and Technology Policy 

Primary Flight Display 

Area Navigation 

Research & Development 

Radio Technical Commission for Aeronautics 

Small Business Innovative Research (program) 

Single Pilot Instrument Flight Rules (program) 

blight Director System 

Supersonic Transport 

Service Test and Evaluation Program 

Terminal Area Productivity 

Traffic Alert and Collision Avoidance System 

Terminal Configured Vehicle 

Terminal Doppler Weather Radar 

Total Energy Control System 

Take-Off Performance Monitoring System 

Time Reference Scanning Beam (MLS) 

Transport Systems Research Vehicle 

Ultra High Frequency 

Velocity Vector Control Wheel Steering 

Visual Flight Rules 

Very High Frequency 

Wallops Flight Facility 
Airbornr Trtlilbhwr 
NASA Boeing 737 

Transport !+;erns Research Vehicle L d 

Specifications 

MODEL: 

DATE OF MANUFACTURE: 

FIRST FLIGHT: 

DESCRIPTION: 

TOTAL FLIGHT HOURS: 

Upon arrival at Langley 

At end of FY 1993 

SPECIFICATIONS: 

Engines (2) 

Wing Span 

Length 

Wing Area 

Tail Height 

Gross Takeoff Weight 

Max Payload 

Cruising Speed 

Range 

Service Ceiling 

Boeing 737-1 30* 

Serial No. 19437 

Boeing Designation: PA-099 

(Prototype Boeing 737) 

*(Aircraft was a 737-100, 

given customer designation 

of 737- 130 when modified to 

NASA specifications) 

1967 

April 9, 1967 

Twin-jet, short-range transport 

978 

2,936 

Pratt & Whitney JT8D-7 

14,000 Ibs thrust each 

93 ft. 

94 ft. 

980 sq. ft. 

37 ft. 

97,800 lbs. 

29,000 lbs. 

575 mph 

2 140 statute miles 

35,000 ft. 

NASA 737 TSRV Flights 

Flight # 

1 

2 

3 

4 

(through FY 1993) 

Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

6/7/74 3:30 3:30 WFF Handling Qualities 

61 1 1 I74 3:07 3:07 WFF Handling Qualities 

611 8/74 2:06 2:06 WFF Handling Qualities 

6120174 2:42 2:42 WFF RNAV Documentation ~~~~~~~~ ~~~ ~ ~ 

5 1 6/25/74 2:29 2:29 j WFF 1 Handling Qualities 
Flight # Date Total Flight Time Research Flight Time rest Site Flight Test Objectives 

1014174 0:52 0:00 

1017174 3:34 3:34 

10/11/74 3:51 0:oo 

19B Auto FLTCTL Sys Dev 

20 XIF F Baseline Noise Meas 

21A XIF F Autoland Development 

21B 10/11/74 I 0:21 I 0:oo Auto FLTCTL Sys Dev 

FAA Baseline 

FAA Baseline 

Autoland Development 

22 10129174 1 1:35 I 1:35 \TAFEC 

23A lo13 1 174 1:33 1 :33 VAFEC 

1013 1 I74 2:17 0:00 

1013 1 174 2:08 O:oo 

1 1/5/74 1:32 O:oo 

11/5/74 3:11 3:11 

1 1/6/74 3:42 3:42 

11/8/74 1 :04 1:04 

1 1/8/74 0:14 0:00 

1 1/8/74 

11/12/74 0:45 0:45 

__ 

~___~ 

______ 

~ 

23B WF F 

23C WFF Flt Director Dev 

24A WF F Autoland Development 

24B WF F Flt Director Dev 

FAA Baseline 

FAA Baseline 

25 VAFEC 

VAFEC 

~ 

~~ 

WF F 

WFF 

Autoland Development 

Flt Director Ilev 

FAA Baseline 

FAA Baseline 

FAA Baseline 

~__-_ 

p___~__ -__ 

~_ - - 

- ~~ - - ___~__ 

VAFEC 

28 VAFEC 

VAFEC 

VAFEC 

~~ 

29 

FAA Baseline 

FAA Baseline 

FAA Baseline 

FAA Baseline 

FAA Baseline 

RNAV Documentxion 

Auto FLTCl’L Sys Lkv 

KNAV Ihumentation 

RNAV Document‘ition 

IiNAV Documentation 

Maintenance 

Maintenance 

-______ ~~~ 

-___ 

___-_ ~_ ___~_- 

-- ~- ~ 

- ~ ~- 

_-______-___- 

-- ~ 

- ~ 

~ - 

__~____ -~ 

__ ~ ~~ - 

VAFEC 

VAFEC 

__p 

32 

VAFEC 

VAFEC 

~- 

WFF 

WFF 

WFF 

VCWS-Autoflt Ctl -~~p ~ 

VCWS-Autoflt Ctl 

VCWS-Au tot1 t C tl 

Pilot Proficiency 

Pilot Proficicncy 

VCWS-Autoflt Ctl 

CWS-IL,S Nav Ilev 

5 Deg Appr Noiw 

VCWS-Autoflt Ctl 

Pilot Proficicncy 

VCWS-Autoflt Ctl 

VCWS-Autotlt Ctl 

5 Ileg Appr NOIW 

~ 

- -- -p 

p___ - 

-__p p- 

~_-p_ ~ 

__p-~ - - 

__ __ 

-- -~ -- - 

- 

NAFEC 

NAFEC 

Pilot I’roficicncy 

Pilot I’roficicncy 

VCWS-Autoflt <:ti 

Pilot Proficiency 

- 

~~ 

- - - ~~ ~ 

Airborne fiailbhzer 
Flight # 

55 

56 

57 

I 58 I 7/25/75 I 2:42 I 2:42 1 WFF I RNAV Documentation 1 

Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

71 18/75 1:57 0:oo WFF CWS-ILS Nav Dev 

7/22/75 - 1 :oo 1 :oo WFF Baseline Noise Meas 

7/24/75 2:12 0:oo NAFEC VCWS-Autoflt Ctl 

5 9A 

59B 

60 

61 

62A 

I 62B I 8/5/75 I 2:26 I 0:oo I I Pilot Proficiency 1 

7130175 1:35 0:oo WFF Laser Antenna C/O 

7/30/75 2:15 0:oo WFF C-Band Beacon Check 

713 1/75 2:22 2:22 WFF Baseline Noise Meas 

8/1/75 3:19 3:19 WFF Baseline Noise Meas 

8/5/75 1:55 0:oo Pilot Proficiencv 

I 63 

64 

65 

66 

67A 

67B 

68 I 9/8/75 I 0:50 I 0:oo 1 1 Maintenance 1 

8/25/75 2:23 0:oo Pilot Proficiency 

8/29/75 4:Ol 0:oo Pilot Proficiency 

9/2/75 2:oo 2:oo WFF RNAV Documentation 

9/3/75 2:05 2:05 WFF 4-D Nav Guidance Doc 

9/4/75 1:Ol 0:oo WFF Handling Qualities 

9/4/75 2:09 2:09 NAFEC ICAO-MLS Dev FAA 

69 I 9/15/75 I 1 :oo I 0:oo I 1 Maintenance 1 

70 

71 

72 

73 

9/22/75 1:15 0:oo Maintenance 

9/24/75 0:47 0:oo Maintenance 

9/26/75 1 :oo 0:oo Maintenance 

3130175 1:55 1:55 WFF RNAV Documentation 

74 1 10/1/75 I 0:20 I 0:20 1 WFF 1 4-D Nav Guidance Doc 

76 

77 

78 

75 1 1013175 I 0:30 I 0:oo I I Maintenance 

1018175 0:40 0:oo Maintenance 

10/10/75 0:50 0:oo Maintenance 

101 1417 5 3:05 3:05 WFF 4-D Nav Guidance Doc 

81 ' 1211 1/75 

79 1 10/20/75 I 0:25 I 0:oo I 1 Maintenance 

0:55 0:oo Maintenance 

80 I 12/9/75 I 0:55 I 0:oo I 1 Maintenance 

82A 12/17/75 

82B 12/17/75 

83 121 18/75 

84 i 12/18/75 

0:35 0:04 WFF Handling Qualities 1 

1:05 0:oo NAFEC MLS Antenna Meas 

2:15 0:oo NAFEC MLS Antenna Meas 

1 :oo 0:1o WFF Handling: Oualities 

1/23/76 

87A 1 21 13/76 I 0:48 I 0:48 

87B 211 3/76 1 :42 0:oo 

88 2/27/76 2:40 0:oo 

89 3/3/76 l:oo 0:oo 

90 3/5/93 0:lO 0:oo 

I 2:25 

1 Thrust Pitch 

Pilot Proficiency 

RSFS Exp Sys C/O 

Maintenance 

' WFF 

WFF RSFS EXP Svs C/O 

1130176 

91 3/7/76 

92 31 1 1 176 

93 3/17/76 

94 3/22/76 

I 

______ 

i 1 :20 

3:35 O:oo Maintenance 

2:30 O:oo WFF RSFS Exp Sys C/O 

2:19 2:19 WFF 4-D Nav Guidance Doc 

0:55 o:00 NAFEC ICAO-MLS Dev FAA 

_~ 

~ 

I-. 

95 

0:oo 

3/23/76 I 2:05 I 2:05 1 NAFEC 1 ICAO-MLS Dev FAA 

0:oo 

Maintenance 1 I Angle of Attack C/O 
- 

Date 

3/24/76 

Flight # 'otal Flight Time rest Site Flight Test Objectives 

2:40 

253 

1:45 

Research Flight Time I 

96 2:40 ZFEC ICAO-MLS Dev FAA 

\TAFEC ICAO-MLS Dev FAA 97 3/25/76 

3/29/76 

3130176 

2:08 

0:oo Maintenance 98 

0:50 0:oo \TAFEC ICAO-MLS Dev FAA 

ICAO-MLS Dev FAA 

ICAO-MLS Dev FAA 

99A 

99B 3130176 1:25 1:25 \IAFEC 

313 1 I76 2:45 2:45 \IAFEC 

~ 

41 1 I76 1:30 130 qAFEC ICAO-MLS Dev FAA 

41 1 176 1:25 \JAFEC ICAO-MLS Dev FAA 

4/2/76 

1:25 

1 :30 130 \JAFEC ICAO-MLS Dev FAA 

0:40 

0:40 

2:oo 

0:54 

2:oo 

______ 

___ 

4/2/76 

41 13/76 

41 13/76 

41 13/76 

41 14/76 

41 14/76 

4/22/76 

4/23/76 

4/23/76 

4/24/76 

4/24/70 

4/24/76 

4/29/76 

4/29/76 

4/29/76 

4130176 

4/30/70 

51 1 176 

51 I 176 

5/2/76 

5/2/70 

5/2/70 

5/2/76 

~__ 

~ 

~~ - 

~~ - 

~ ~~~ 

~~ 

~~~- 

~~~~ 

~___ 

~ ~ 

~~ ~ 

~ 

~~~~ ~ 

~ 

~~~ ~ 

~- 

~ ~~ 

~~ 

~~~ 

~~ 

0:42 

037 

0:15 

~~ 

0:40 

5/3/70 

516176 

516170 

5/6/70 

5/7/76 

5/7/76 

5 17/70 

5 17/70 

5 I7 170 

5/7/70 

5 I8 I76 

51 1 I I70 

511 1/76 

~~ 

~~ 

0:oo 

0:oo 

0:oo NAFEC 

NAFE:<: 

0:20 NAFEC: 

0:37 

0:40 

0:36 

0:40 

0:50 

0:50 

0: 5 2 

1 :20 

~~ 

0:40 

0:oo 

0:oo 

0:52 

1 :20 

~~ 

51 12/76 N A F E( ; MIS Ilenio to ICAO 
Flight # 

I 117B 1 5/12/76 1 0:33 I 0:33 1 NAFEC 1 MLSDemotoICAO 

Date I Total Flight Time Research Flight Time Test Site Flight Test Objectives 

I 117C i 5/12/76 I 1:15 I 1:15 I NAFEC 1 MLS Demo to ICAO 

118A 

118B 

ll8C 

119A 

5/13/76 0:35 0:35 NAFEC MLS Demo to ICAO 

5/13/76 1:ll 1:ll NAFEC MLS Demo to ICAO 

5/13/76 1:lO 1:lO NAFEC MLS Demo to ICAO 

5/14/76 0:45 0:oo NAFEC MLS Demo to ICAO 

~~ 

I 119B i 5/14/76 I 0:45 I 0:oo I NAFEC I MLS Demo to ICAO 

11% 

120 

121A 

121B 

5/14/76 0:45 0:oo NAFEC MLS Demo to ICAO 

5/17/76 1 :oo 0:OO NAFEC MLS Demo to ICAO 

51 18/76 0:40 0:40 NAFEC MLS Demo to ICAO 

511 8/76 0:50 0:50 NAFEC MLS Demo to ICAO 

I 122A 1 5/19/76 I 1 :20 I 1:20 1 NAFEC I MLSDemotoICAO 

123A 5120176 

123B 5120176 

123C 5/20/76 

124 512 1/76 

I 122B ~ 5/19/76 I 1:lO I 1:lO 1 NAFEC 1 MLS Demo to ICAO 

0:45 0:45 NAFEC MLS Demo to ICAO 

1 :00 l:oo NAFEC MLS Demo to ICAO 

1:20 1:20 NAFEC MLS Demo to ICAO 

1:50 0:oo NAFEC MLS Demo to ICAO 

125B 

I 125A 1 6/8/76 1 0:50 I 0:oo I 1 Maintenance 

6/8/76 0:40 0:oo Maintenance 

126A 1 6/11/76 

126B 611 1/76 

127A 61 16/76 

2:30 0:oo NAC VCWS-Autoflt Ctl 

1:35 1:35 WFF Handling Qualities 

1:45 1:45 WFF Handling Qualities 

1:20 WFF 

2:05 NAFEC 

~~~ 

Handling Qualities 

CWS-ILS Nav Dev 

127B 1 :20 

128 0:oo 

61 16/76 

6/22/76 

129A 6/24/76 2:oo 0:oo Angle of Attack C/O 

129B 6/24/76 1:15 0:oo WFF Aerodynamic Noise 

130A 6/27/76 0:25 0:oo WFF 4-D Nav Guidance Doc 

130B 6/27/76 1:20 1 :20 WFF 4-D Nav Guidance Doc 

130C 6/29/76 1:oo 0:oo WFF Laser Antenna C/O 

131A 7/7/76 0:45 0:oo NAFEC MLS Driven Displays 

131B 7/7/76 2:30 230 NAFEC M1.S Driven Digplay. 

131C 7/7/76 0:45 0:oo NAFEC MLS Driven Displays 

132A ~ 7/9/76 1 :oo O:oo NAFEC Antenna Test 

~- 

132B I 7/9/76 0:30 0:30 NAFEC Antenna Test 

132E 7/9/76 I 1:oo I O:oo 

133A I 71 13/76 0:52 0:oo 

133B 1 71 13/76 2:oo 2:oo 

133C ' 71 13/76 1:25 1 :oo 

134A , 71 15/76 0:55 O:oo 

134B 71 15/76 1:oo 1 :oo 

I 

______ 

I 132C 1 

' Antenna Test 

NAFEC MLS Driven Displays 

NAFEC MLS Driven Displays 

NAFEC MLS Driven Displays 

NAFEC VCWS-Autoflt Ctl 

NAFEC Body Mounted Accel 

I 

71 15/76 2:15 2:15 NAFEC Body Mounted Accel 

134D 711 5/76 0:45 O:oo NAFEC Body Mounted Accel 

135A 7120176 0:50 0:oo NAFEC Body Mounted Accel 

135B 7120176 1:25 1 :25 NAFEC Body Mounted Accel 

____ 

______ 

I 132D 1 

7/9/76 1 :04 

7/9/76 1:ll 

1 :04 

1:ll 

~- 1 NAFEC I EL-2 Flare 

1 NAFEC I MLS Driven Displays 

___ 
'otal Flight Time -est Site I Flight Test Objectives 

1:20 

0:40 

Flight # Date Research Flight Time 

135C 7120176 

I 

1:20 ZFEC 1 Body Mounted Accel 

JAFEC Body Mounted Accel 

JAFEC Body Mounted Accel 

JAFEC MLS Demo TRSB 

JAFEC MLS Demo TRSB 

JAFEC MLS Demo TRSB 

\TAFEC MLS Demo TRSB 

135D 7/20/76 0:oo 

135E 7120176 

136A 7/26/76 

136B 7/26/76 

136C 7/26/76 

137A 7/29/76 

137B 7/29/76 

137C 7/29/76 

138A 8/2/76 

I38B 8/2/76 

138C 8/2/76 

130A 8/3/76 

l39H 8/3/76 

8/3/76 

8/3/76 

8/5/76 

8/5/76 

8/5/76 

-- 

-- 

___~ -~ - 

~~ -~ 

-~ - ~-~~ -

-~ __ 

~~ 

~ -- 

~ 

141A 

141B 813 1 176 

141C 8/31/76 

142A 9/8/76 

14213 9/8/76 

141 911 4/76 

144 9/22/76 

145 9/29/76 

146A ~ 101 1 176 

146C - 10%76 

147 10/4/76 

148 101 13/76 

149A 10/19/76 

14OR 10/1 9/76 

140C 1 O/I 9/76 

14911 101 19/76 

15OA 10/2 1 176 

1 SOB 10/2 1/76 

50c: 10/2 1/76 

5011 10/2 1/76 

51A I0/28/76 

5113 10/28/70 

~ __ - 

~~ ~~ _- -- 

~~ 

-~ 

-_ 

-~ - ~ ~ 

~ - -~ ~ 

14613 7 IO/l/76 ~- ~ 

~~ -~ 

- ~ ~ 

- ~~ ~- ~ 

~~ - ~ 

~. - 

-~ ~ ~ 

-~ -_ ~ 

~~ ~ ~ ~ ~ 

- ~ ~- 

~ 

- 

1 :00 0:oo 

1:oo O:oo 

0:50 0:50 

1:oo 0:00 

0:50 0:oo 

1:30 

- 

1:30 \TAFEC 1 MLSDemoTRSB 

0:50 0:00 \IAFEC 

0:45 0:oo \JAFEC 

1:10 

0:oo 

0:00 

- 

Mainrenance 

4-11 Nav Guidance I)oc 

4-11 Nav (;uidaiicc l)oc 

4-Ll Nav (;dance l>oc 

4-11 Nav (;uidancc l1oc 

Functional Flt 1)emo 

Functional Flt lhio 

Functional Flt Ikmo 

I:unctional Flt I1cmo 

Functional Flt 1)emo 

I:unctional Flr Ikmo 

~~ ~~ -~ 

~ ~~ 

~~~ 

~~~ ~ 

~~ ~ ~~ 

039 

1 :35 

1 :os 

0:57 

0:33 

1 :oo 

1 :oo 

036 

033 

52A 11/1/70 

15213 1 l/1/70 

152(: 1 1/1/76 

153A 11/2/76 

~ 

0:50 

1 :00 

~ 

I:unctioncil Flt 1)cmo 

Functional Flt Ilcmo 

Airborrrr Kcrilbhzzrr 
Flight # 

153B 

154 

Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

11/2/76 0:45 0:45 WFF Functional Flt Demo 

11/4/76 2:12 0:oo Angle of Attack C/O 

155 

156A 

156B ______ 

~~~ 

1 1/9/76 2:09 0:oo Aerodynamic Noise 

11/11/76 1:30 1 :30 WFF Functional Flt Demo 

1111 1/76 0:21 0:oo Pilot Proficiency 

~~~~~~ 

~- 

157 11/29/76 1:30 

158 121 10176 1:15 

159A 1 I1 9/77 l:oo 

0:oo Maintenance 

0:oo Maintenance 

0:oo Pilot Proficienw 

159B 

159C 

1 GOA 

16OB 

161 _____ 

162 

______ 1 I1 9/77 0:40 0:oo j Pilot Proficiency 

1/19/77 0:45 0:oo Pilot Proficiency 

112 1/76 1 :40 1:lO WFF Spoiler Aileron Test 

1/21/76 1 :00 1 :oo WFF Runway Turnoff Test 

31 10177 1 :oo 0:oo Mag Heading Compar 

31 1 1 I77 1:Ol 0:oo Maintenance 

______~_____________ 

________~ 

179 1018177 2:50 2:50 - NAFEC 

180 101 10177 NAFEC 

181 1011 1/77 2:15 2:15 NAFEC 

182 101 12/77 2:oo 2:oo NAFEC 

183 1 10/13/77 1:lO 0:50 NAFEC I 

184 ~ 101 17/77 

~~

2:oo 0:oo NAFEC 

185 I 10/20/77 235 2:35 NAFEC 

NAFEC MLS Dev Flts 

NAFEC MLS Dev Flts 

NAFEC MLS Dev Flts 

NAFEC MLS Dev Flts 

NAFEC MLS Dev Flts 

Maintenance 

New Vel/CWS Cont Dis I I ~ 

' 

189A 10/26/77 0:50 0:50 Buenos Aires TRSB Demo, Argentina 

189B 10/26/77 0:50 

190A 10127177 0:24 

190B 7 10127177 1:35 

__________ 

- 

---L _____~ -__ 

0:50 Buenos Aires TRSB Demo, Argentina 

0:oo Buenos Aires TRSB Demo, Argentina 

1:35 ~ Buenos Aires TRSB Demo, Argentina 

190C 1 10/27/77 0:30 I 0:oo Buenos Aires TRSB Demo, Argentina 
Research Flight Time Test Site Flight Test Objectives 

0:oo Buenos Aires TRSB Demo, Argentina 

3:OO Buenos Aires TRSB Demo, Argentina 

0:oo Buenos Aires TRSB Demo, Argentina 

O:oo Buenos Ares TRSB Demo, Argentina 

1:15 Buenos Aires TRSB Demo, Argentina 

O:oo Buenos Aires TRSB Demo, Argentina 

1 :25 Buenos Aires j TRSB Demo, Argentina 

-- 

pp 

_~ 

~- 

Flight # 'otal Flight Time 

0:25 

Date 

10128177 

10128177 

10128177 

191A 

191B 3:OO 

191C 0:15 

192A 10/29/77 0:25 

1928 

192C 

~___~ 

10/29/77 1:15 

10129177 0:20 

193A 1013 1 177 1:25 

1938 1013 1 177 1:oo 1 :oo I Buenos Aires 1 TRSB Demo, Argentina 

10131/77 0:20 0:oo Buenos Aires ' TRSB Demo, Argentina 

0:oo Buenos Aires TRSR Demo, Argentina 

2:50 Buenos Aires TRSB Demo, Argentina 

0:OO Ruenos Aim TRSR Ilemo, Argentitu 

0:OO Ruenos Aires TRSR Demo, Argentina 

1 :25 TRSR Demo, Argcntin<i 

1 :03 'I'RSR 1)emo. Argentin'i 

-- 

~ ~ 

__~_____ - ~-__- 

_____ ~-~ ~- _- ~ - - 

____- ~ ~ ~ - ~ -- 

~- - ~ ~- -- 

193C 

11/1/77 

11/1/77 

11/1/77 

1 1/2/77 

1 1/2/77 

1 1/2/77 

1 1/2/77 

1 1/3/77 

1 1/3/77 

1 1/3/77 

1 1/4/77 

11/4/77 

1 1/4/77 

1 1/7/77 

1 1/7/77 

1 1/8/77 

~ ____~- - 

- -_ 

-~ -~ - 

- 

~ ~ 

~~ 

~~ _- 

~ -__- 

--- - 

- 

~ ~__ 

- 

~~~ - _ - 

~ ~~ ~ 

o:2o 

TRSR Demo, Argentina ~__~ 

TRSB Demo, Argentina 

TRSB Demo, Argentina 

TRSB Demo, Argentina 

TKSB Demo, Argentina 

TRSB Demo, Argentina 

Nav Expcrimcnts 

Nav Experiments 

Nav Experiments 

Nav Experiiiients 

Maintenance 

- 

- ~~ ~~~~ ~ ~ ~ - 

~ ~ - 

- __~- 

~~ - - 

- ~ 

_ 

1 1/9/77 

1 1/3/77 

11/10/77 

1 1/22/77 

1 1/23/77 

12/2/77 

12/4/77 

12/5/77 

12/6/77 

12/7/77 

12/8/77 

12/9/77 

12/10/77 

121 12/77 

121 I 3/77 

1 21 14/77 

21 17/78 

2/24/78 

~___ 

-~_ -

- 

-~~ - 

- - 

- 

-~ -- 

~ ~___ 

- - 

~__ -_ 

~ -- 

__ ~ 

- 

- - 

200R 

20 1 

202 

203 

204 

205 

206 

207 

208 

209 

210 

21 1 

212 

~ ~~ 

~- - 

~ 

~~ - 

~~ 

~- 

- 

~ 

~ 

~- 

4:OO 

3:OO -~ 

213 

214 

215 

216 

217 

~~ 

218A 3/ 15/78 

311 5/78 

1:Il 

218R 0:35 
> 

Flight # Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

218C 3/ 15/78 0:18 0:18 Energy ProbIWindsherar 

218D 3/ 15/78 0:35 0:35 NOR Variable Tau Flare 

218E 3/ 15/78 0:07 0:07 NOR Prelim CDTI Exp 

218F 3/ 15/78 0:35 0:35 NOR Nav. ExDmts-Montreal 

~~________ ~ 

______

I 218G 1 3/15/78 I 0:18 I 0:18 I NOR I ILS Auto Missed Avvr 1 ~ 

218H 

219A 

219B 

219C 

219D 

219E 

31 15/78 1:11 1:ll NOR TRSBIMLS Demo Canada 

3/16/78 0:46 0:46 SSFD Sys. C/O 

31 16/78 0:24 0:24 ILS Auto Missed Appr 

31 16/78 0:15 0:15 Energy ProbIWindsherar 

3/16/78 1 :06 1 :06 Variable Tau Flare 

3/16/78 0:54 0:54 Variable Tau Flare 

220 I 3120178 

22 1A 3/22/78 

221B I 3/22/78 

221c 3/22/78 

222A I 3 12 9 17 8 

222B 3/29/78 

1:35 1:35 NAFEC Nav. Expmts-Montreal 

1:25 1:25 CAN TRSBIMLS Demo Canada 

2:40 2:40 CAN TRSBIMLS Demo Canada 

1:15 1:15 CAN TRSBIMLS Demo Canada 

1:20 1 :20 CAN TRSBIMLS Demo Canada 

1:lO 1:lO CAN TRSBlMLS Demo Canada 

230B ' 4/7/78 

231-4 4!8!78 

231B 4/8/78 

232A 4/12/78 

232B 41 12/78 

1:lO 1:lO CAN TRSBIMLS Demo Canada 

T~CD/IXT c n ---- r ___. J. ::!5 ::I5 

1 :oo 1 :oo CAN TRSBIMLS Demo Canada 

1 :oo 1 :oo CAN TRSBIMLS Demo Canada 

1 :oo I l:oo I CAN I TRSBIMLS Demo Canada 

C,2N I I\c)UI IVILJ UClllU bdlldUd 

______________ 

__ 

232c 41 12/78 I 0:40 0:40 1 CAN ~ TRSBIMLS Demo Canada 

233 I 4/ 13/78 1 :oo 1 :oo CAN TRSBIMLS Demo Canada 

234A 4/ 14/78 1:lO 1:lO CAN TKSBIMLS Demo Canada 

234B , 4/14/78 l:oo l:oo CAN TRSBIMLS Demo Canada 

23% 4/15/78 1 :oo 1 :oo CAN TRSBIMLS Demo Canada 

235B 41 15/78 1 :oo I 1 :oo TRSBIMLS Demo Canada 

236A 41 16/78 1:oo 1:oo TRSBIMLS Demo Canada 

236B 4/ 16/78 1:05 1:05 CAN TRSBIMLS Demo Canada 

_______ 

--_ -- 

_________~~ -~ - 

______~~~_~ 

-- 

237 4/ 17/78 

238 5/9/78 ____ 

1:40 1 :40 Nav. Expmts-Montreal 

0:55 o:oo Maintenance 

~__ 

~ 

239A -7 1:2o 0:oo --1---Innncc ~________ 

I 239B 5/ 19/78 I 2:1o -~ +-A _____ 

0:oo 1 Maintenance 
rotal Flight Time I Research Flight Time rest Site Flight Test Objectives 

Maintenance 

Maintenance 

Maintenance 

EL-2 TRSB Flare 

EL-2 TRSB Flare 

MLS Back Azimuth 

EL-2 TRSB Flare 

EL-2 TRSB Flare 

EL-2 TRSB Flare 

E1.-2 TRSB Flare 

EL-2 TKSB Flare 

EL-2 TRSB Flare 

Path In Space Flarc 

EL-2 TRSB Flare 

EL-2 TIISB Flare 

Maintenance 

Maintenance 

Maintenance 

MLS Back Azimuth 

MLS Back Azimuth 

MIS Back Aziniuth 

MIS Back Azimuth 

MI,S Back Azimuth 

E1.-2 TIISB Flare 

E1.-2 TKSR Flare 

MI5 Rack Azimuth 

EL2 TRSR Flare 

EL2 1‘IISB Flare 

E1.-2 7’1V33 Flarc 

I’ath In Space Narc 

EL2 ‘I’IISB Flarc 

E1,-2 TRSB Narc 

M1.S Hack A/,iniiith 

E1.-2 ‘I’IISR Flare 

~___ 

____ 

__ ~ ~~~ 

~____ 

~~~ - - 

P~- ~ - - -~ -~ 

- ~.P- -~ -~ -~- ~ 

~ 

- ~- ~ -. 

~ -~ -~ 

~~-- - -- 

~-- 

~ 

- - ~~ - ~- ~ 

~ - ~- ~ 

~~ - ~~ - - ~ ~ 

P~ - -~ ~ 

- ~~ ~P 

- ~ 

~~ -~ - 

-_ ~~~ ~ 

- - -~ 

~ - ~~ 

- ~~ 

-~ - ~ 

~ ~ 

~ - -~ 

Flight ## Date 

240A 

240B 

24 1 

- I - 

6/7/78 0:45 I O:oo 

6/7/78 0:oo 

6/27/78 0:oo 

242 7/17/78 VAFEC 

71 19/78 

712 1 178 

243 3:35 I 3:35 VAFEC 

VAFEC 

VAFEC 

244A 

244B 

244C 

7/21/78 

VAFEC 

VAFEC 

~ 

7/21/78 

245A 7/25/78 

YAFEC - 245B 

245C 

246A 

246R 

246C 

24613 

247A 

247B 

247C 

248A 

248B 

249A 

249R 

249C 

250A 

250R 

250C 

250D 

251A 

251B 

251C 

25111 

252A 

252B 

252C 

252D 

252E 

253A 

253B 

253c 

254A 

-__~ - 

- ~~ - 

~ - 

~ 

~- - 

~-_ 

_~_ - 

~-- 

~ ~ 

-~ 

~ ~ 

~-~ 

~~ 

~ 

- 

~- - 

~ 

_- ~ 

~ 

~P 

-- 

~ 

NAFEC 

NAFEC: 

NAFEC 

NAFEC 

NAFEC 

~- 

P~-~ 

~ 

~ 

~ 

~- 

NAFEC 

NAFEC 

NAFEC 

NAFEC 

NAFEC 

NAFEC 

~~ 

~- ~ 

~ 

~ 

8 I2 2 I7 8 

8/12/78 

8 / 2 2 17 8 

8/28/78 

8/28/78 

8/28/78 

8/.30/78 

8/.30178 

8/.Z0/78 

01 1/78 

o/ 1/78 

(I/ I 178 

01 1 178 

~~ 

P~ ~ 

~ 

25413 

254: 

255A 

25513 

255C 

MI5 Ihck Azimuth 

0:3 1 I 0:3 1 

0:47 1- o:47 

0: 12 I --IP 0: 12 

hli In Space Flarc 

M1.S Hack Axiniiith 

MIS Rack Azimuth 

~- 

2551) 

Airborne Trdbhzrr 
Flight # Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

256A 9/6/78 0:50 0:oo NAFEC MLS Back Azimuth 

256B 9/6/78 2:lO 2:lO NAFEC MLS Back Azimuth 

256C 9/6/78 1 :oo 1 :oo NAFEC Path In Space Flare 

257A 9/8/78 0:35 0:oo NAFEC MLS Back Azimuth 

1 

~~ 

1 ~~ ~~ ~~ I 257B 1 9/8/78 I 3:OO I 3:OO 1 NAFEC I MLS Back Azimuth 

258A 

258B 

258C 

I 257C 1 9/8/78 I 0:55 I 0:oo I NAFEC I Path In Space Flare 1 

91 12/78 1 :oo 0:oo NAFEC Path In Space Flare 

91 12/78 2:lO 2:lO NAFEC MLS Back Azimuth 

9/12/78 0:45 0:oo NAFEC ~- Path In Space Flare 

259A 1 9/14/78 

I 259B 1 9/14/78 1 2:30 1 230 I NAFEC I MLS Back Azimuth 1 

0:55 I 0:55 NAFEC MLS Back Azimuth 

259C 9/14/78 0:55 0:oo NAFEC Path In Space Flare 

260A 91 18/78 1 :oo 0:oo NAFEC Path In Space Flare 

260B 9/ 18/78 1:lO 1:10 NAFEC Path In Space Flare 

- 260C 91 18/78 0:50 0:50 NAFEC Path In Space Flare 

261A 9120178 3:OO 2:lO NAFEC Path In Space Flare 

261B 9120178 0:45 0:oo NAFEC Path In Space Flare 

262A 9/22/78 

262B 9/22/78 

9/22/78 262C 

263 10/30/78 

- 264A 1 1/7/78 

264B 1 1/7/78 

264C 1 1 1/7/78 

I 

__~_~ 

3:OO 3:OO NAFEC Path In Space Flare 

1 :oo l:oo NAFEC Path In Space Flare 

0:50 0:oo NAFEC Path In Space Flare 

1 :20 0:oo NAFEC Maintenance 

0:40 0:oo NAFEC EL-2 TRSB Flare 

1:21 1:21 NAFEC EL-2 TRSB Flare 

0:29 0:29 WFF Path In Space Flare 

___________________ 

~_______

~ 

I 268A ' ~~ 

11/30/78 

~ 

~ I 0:35 I 0:oo ~ WFF 

1 

I FRF CIOfor CDTI ---

264D ' 11/7/78 

265A 11/9/78 

265B 11/9/78 

266A 11/20/78 

266B 11/20/78 

266C 

267A 11/28/78 

267B 11/28/78 

267C ~ 11/28/78 

___ 

I 268B I 11/30/78 1 0:40 I 0:oo 1 WFF I FRF c/o for CDTI 1 

1:lO 1:lO VCWS-Autoflt Ctl 

0:35 0:oo WFF Sim MLS Dev Flts 

0:25 0:25 WFF Sim MLS Dev Flts 

0:45 0:oo NAFEC EL-2 TRSB Flare 

2:25 2:25 NAFEC EL-2 TRSB Flare 

0:55 0:oo NAFEC EL-2 TRSB Flare 

0:30 0:oo WFF CDTI-Phase 1 Exp 

2:oo 2:oo WFF CDTI-Phase 1 Exp 

0:25 0:oo WFF CDTI-Phase 1 EXD 

~~ 

~~ -- 

I 1 269 I 12/5/78 I 2:lO I 1:25 1 NAFEC 1 EL-2 TRSB Flare 

1 263 ' 12/5/78 

I 270A 12/7/78 

, 270B 12/7/78 

270C 12/7/78 

270D I 12/7/78 

2:lO 1:25 ~ NAFEC ~ Path In Space Flare 

1:16 1:16 WFF CDTI-Phase 1 Exp 

2:07 2:07 WFF CDTI-Phase 1 Exp 

1:32 1:32 WFF CDTI-Phase 1 Exp 

0:20 0:oo WFF CDTI-Phase 1 Exp 

27 1 21 1 5/79 

273 4/9/79 

274 41 10179 

275 I 41 12/79 

272 3/22/79 

1 

-_ Maintenance 

Pilot Proficiency 

Maintenance 

___ 1:40 0:oo 

2:lO 0:oo 

1 :40 0:oo 

-, 

3:lO 2:1o Handling Qualities 

535 I 2:05 1 NAFEC 1 Handling Oualities 

NAFEC _____ ~ - 
-~ 

Date rota1 Flight Time Research Flight Time I Test Site Flight Test Objectives 

3:45 

1:15 

0:25 

2:30 

Flight # 

276 

277A 

277B 

~~~ ~ 

LFMIPD C/O 

FRF C/O for CDTI 

41 17/79 3:45 

4/13/79 

4/19/79 

4/24/79 

4/24/79 

WFF 

WFF 

0:30 

0:10 Enerw ProbIWindshear 

278 1 :45 WFF Sirn MLS Dev Flts 

278 

279 

279A 

2798 

_____ 

0:55 0:40 WFF Energy ProbIWindshear 

Maintenance 

Sim MLS Dev Flts 

Sirn MLS Dev Flts 

4/26/79 1:35 0:oo WFF 

WFF 

WFF 

5/1/79 0:35 0:00 

2:05 

0:00 

51 1 179 295 

279C 0:35 WFF 

2:55 

2:45 

I :00 

3:15 

1 :oo 

310 

3:OO 

3:10 

2:50 

4:00 

1 :20 

315 

3:30 

330 

3:20 

330 

3:15 

3: 10 

3:05 

3:50 

3:50 

4: 10 

I:50 

315 

0:40 

0:45 

1 :oo 

1:lO 

0:50 

0: 5 5 

1 :05 

4:05 

2: IO 

520 

220 

0:40 

0:25 

~___ 

__~ 

__- 

- 

~ 

~ 

~~ 

~ 

~~ 

~ 

~ 

~ 

~ 

~ 

- 

~ 

~ 

~~ 

~ 

- 

6/27/79 

GI 2 x I7 ‘I 

6/29/79 

71 10/79 

7/17/79 

71 19/79 

7/24/79 

~ 8/7/79 

81 13/79 

8/29/79 

~- 

~ 

~ ~ 

~ 

~ 

3: 15 

3: 10 

0 : 00 

2:50 

~ 

9120/79 ~ 

9/20/79 

9/20/79 

10/2/79 

10/4/79 

~ 

1:I5 

430 

1:15 

0:OO 

0:25 

- .~ 

~ 

160 
Flight # 

313C 

313D 

313E 

313F 1 10/30/79 I 0:30 I 0:oo I WFF I CDTIIOcculometer 

Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

10/30/79 0:15 0:15 WFF Prelim CDTI Exp 

10/30/79 0:30 0:oo WFF CDTIlOcculometer 

10/30/79 1:30 1:30 WFF CDTIIOcculometer 

~~______ 

314 

315 

316 

317 ~~ 

318 1 11/21/79 1 3:50 I 2:50 I WFF I CDTI/OczoEtei 

11/6/79 2:15 1:25 WFF CDTI Gen Display 

11/8/79 5:30 4:50 WFF CDTI Gen Display 

111 15/79 4:55 3:55 WFF CDTI Gen Display 

11/20/79 0:55 0:oo WFF CDTI/Occulometer 

319A 

319B 

319C 

I I I I I 

11/27/79 0:32 0:oo TBMILFM in ATC 

1 1/27/79 2:24 2:24 TBMILFM in ATC 

11/27/79 0:44 0:44 WFF TBMILFM in ATC 

I 

32 1 12/4/79 I 0:20 I 0:20 I WFF 1 CDTI/Occulometer 

319D ~ 11/27/79 

320 1 11/29/79 

0:30 0:oo TBMILFM in ATC 

4:40 3:50 WFF CDTIIOcculometer 

32 1 12/4/79 

32214 12/5/79 ______ 

0:40 0:15 WFF CDTI Gen Display 

0:20 0:oo WFF Total Energy Probe Test 

322B 

322C 12/5/79 1:30 

322D 12/5/79 0:50 

322E 12/5/79 0:20 

___~~ 

0:50 WFF Total Energy Probe Test 

1:30 WFF 1 CDTI/Occulometer 

0:50 WFF CDTI Gen Display 

0:oo WFF CDTI Gen Display 

323 

324 

325 

326A 

326B 

I 121 17/79 1:35 0:35 Total Energy Probe Test 

4/8/80 1:30 0:oo WFF Maintenance 

411 1/80 2:45 2:45 WFF Open Loop Upgrade 

4/15/80 0:45 0:45 NAFEC Open Loop Upgrade 

4/ 15/80 0:20 1 0:20 NAFEC Open Loop Upgrade 

32% I 4/15/80 

326C ~ 4/15/80 

326D ~ 4/15/80 

0:45 0:45 NAFEC , Autothrottle C/O 

0:30 0:30 NAFEC Autothrottle C/O 

0:lO 0:10 NAFEC Open Loop Upgrade 

~~~ 

______

3261) 4115180 1:55 

327 41 17/80 3:30 

328 1 4/22/80 230 

329A ~ 5/6/80 0:50 

329B 1 5/6/80 0:30 ~~ - 

330 I 5/9/80 2:50 

33 1 ~ 71 14/80 0:40 

332 7/24/80 0:45 - 

333A 12/9/80 0:35 

333B 1 12/9/80 1:25 

_______I_____~ ~~ 

1:55 NAFEC Autothrottle C/O 

3:30 ATL TBMILFM in ATC 

2:30 LOCAL Autothrottle C/O 

0:50 WFF Autothrottle C/O 

_

0:15 I WFF High Speed Turnoff ~ -~ __~~___~ -~ - - 

2:50 1 NAFEC Autothrottle C/O 

0:oo I Maintenance 

0:oo 1 Maintenance 

O:oo ' LOCAL Maintenance -_ 

- I 1:25 1 WFF Open Loop Upgrade 

333c 12/9/80 

334A 12/11/80 

334A 1211 1/80 

334A 1211 1/80 

334B 1 12/11/80 1 

__~ 

1211 1/80 

1 :00 l:oo WFF Dials Flight Test 

0:lO 0:oo WFF Open Loop Upgrade 

0:20 0:20 WFF Open Loop Upgrade 

1:30 1:30 WFF Open Loop Upgrade 

0:30 0:oo i ATR 1 NC Surf Coat Drag 

2:10 2:10 1 ATR 1 NC Surf Coat Drag 

~~ 
- 

'otal Flight Time I Research Flight Time 'est Site Flight Test Objectives ~ 

Flight # 

334B 

335 

336A 

336A 

336B 

Date 

AICSurf Coat Drag 

A/C Surf Coat Drag 

12/11/80 0:40 0:40 

2:45 I 2:45 ;TL 

,TL 

;TL 

1 /20/8 1 

112318 1 

112318 1 

112318 1 

1/27/81 

1:15 I Dials Flight Test 

0:50 

1:15 

A/C Surf Coat Drag 

A/C Surf Coat Drag 

A/C Surf Coat Drag 

A/C Surf Coat Drag 

Open Loop Upgrade 

A/C Surf Coat Drag 

A/C Surf Coat Drag 

Dials Flight Test 

Dials Flight Test 

C/O High Spd Turnoff 

C/O High Spd Turnoff 

Pilot Proficiency 

Pilot Proficiency 

Maintenance 

Maintenance 

Open Loop Upgrade 

Open Loop Upgrade 

Open I oop Upgrade 

Open ~~~ I.oop Upgrade 

Maintenance 

Open Loop Upgrade 

Open I oop Upgrde 

Open I oop Upgrade 

Open 1 oop Upgrxie 

Open 1 oop Upgrade 

-~- 

-~ 

__~_~ ~-~ 

~-~

~~- 

~-~ 

~~ ~ - ~ 

-~

-~ ___ ~~ - ~ - 

~ 

~ - ~~ ~ 

- ~- ~- 

~~ ~ 

~ 

Dials Flight Tat - ~- 

Open 1,oop Upgrade 

Total Lneigy Probe I'cst 

Open Loop Upgrde 

Dids Flight Tc5t 

Ili.iJs Flight Test 

Dials Flight l'est 

New115 Upddtc 

NewILS Upd'ite 

Dids Flight Test 

Dials Flight Tc\t 

New11 S Upchtc 

Newll S Upd<ite 

New11 S Upd.ite 

NcwII S Updttc 

Newll S Upd.itc 

~~ ~ 

~~ ~~~~~ ~ 

- ~~~ ~ 

-~ ~~ 

- ~ 

~ ~ ~~ 

-~ ~ ~ 

- ~~ ~ 

-~ ~ ~ 

- ~~ 

-~~ 

- 

11l<il\ bllgllt '1 est - ~ 

Uids Flight 'I'cst 

0:50 

2:lO 

2:oo 

2:lO LTL 

337A 2:oo 

337A 

337B 

338A 

338A 

1/27/81 0:30 0:oo 

2:15 

2:15 

112718 1 2:15 

0:30 

0:50 

0:25 

0:45 

~- 

0:25 

2:25 

0:25 

0:20 

0:35 

162 Airborne 7iiiiLbhzcr 
Flight # 

352C 

353A 

353B 

353c I 9/29/81 I 0:20 I 0:oo I WFF 1 Dials Flight Test 

Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

812518 1 0:20 0:oo WFF Dials Flight Test 

9/29/81 0:20 0:oo WFF Dials Flight Test 

9/29/8 1 2:40 2:40 WFF Dials Flight Test 

354A 

354B 

354c 

355A 

355A I 10/20/81 ~ 0:30 I 0:30 1 WFF I Flight Path Angle 

10/8/81 0:30 0:oo WFF Flight Path Angle 

10/8/81 0:40 0:40 WFF Flight Path Angle 

10/8/8 1 0:20 0:oo WFF Flight Path Angle 

10/20/81 0:20 0:oo WFF Maintenance 

355A 1 10/20/81 I 0:50 I 0:50 I WFF 1 RNAVIMLS Trans 

355B 

355c 

356A 

356B 

356C 

356C 

10/20/81 1 :40 1 :40 WFF Dials Flight Test 

10/20/8 1 0:20 0:oo WFF Dials Flight Test 

1 11318 1 050 0:oo WFF Flight Path Angle 

11/3/81 1 :oo 1 :oo WFF Flight Path Angle 

11/3/81 0:40 0:40 WFF Flight Path Angle 

11/3/81 1 :20 1:20 WFF Prelim. LCWS 

356C 

357A 

357A 

357B 

357c 

~__ 

357D 1 11/18/81 I 0:15 I 0:oo 1 WFF 1 Dials Flight Test 

1 1/3/8 1 0:25 0:oo WFF Flight Path Angle 

11 /18/8 1 0:40 0:oo WFF Maintenance 

1111 818 1 0:20 0:oo WFF Dials Flight Test 

1 1/18/8 1 0:50 0:50 WFF ILVAV/MLS Trans 

11/18/81 2:oo 2:oo WFF Dials Flieht Test 

358A 1 11/25/81 

358B 11/25/81 

358C 1 112518 1 

359A 121118 1 

359B 121 118 1 

~~ 

0:20 0:oo WFF Dials Flight Test 

l:oo l:oo WF F Total Energy Probe Test 

0:20 0:oo WFF Dials Flight Test 

0:40 0:oo WFF Dials Flight Test 

0:40 0:40 WFF Dials Flight Test 

359c 121118 1 

360A 12/3/81 

360B 1 121318 1 

---- zmr !2!3!8! 

361A 121418 1 

~~ 361A 1 121418 1 

361B 1 121418 1 

I 

I 

0:40 0:oo WFF Dials Flight Test 

0:40 0:oo ATL Maintenance 

1:20 1:20 ATL A/C Surf Coat Drag 

A IC c....c~,.-+ n..",. !?A0 0:00 ..Ab 

2:40 2:40 ATL A/C Surf Coat Drag 

0:25 0:oo WFF A/C Surf Coat Drag 

1:lO 1:lO WFF Dials Flight Test 

5 1" u "Ull -Val -,a A TT 

361C ' 121418 1 

362 121818 1 

363 12/9/81 

364A 1211 1/81 

364B 1 12/11/81 

364C 1211 1/81 

364D 1211 118 1 

1 

I 

I 

0:20 0:oo WFF 1 Dials Flight Test 

2:40 2:40 ATL AIC Surf Coat Drag 

2:20 2:20 ATL AIC Surf Coat Drag 

2:15 2:15 ~ ATL A/C Surf Coat Drag 

0:20 0:oo WFF AIC Surf Coat Drag 

0:50 0:50 WFF Dials Flight Test 

0:20 0:oo WFF Dials Flight Test 

~ ~ ~-~ 

365A 12/16/8 1 0:40 0:oo 1 FAATC NewILS Update I 

1211618 1 

366 ~ 12/18/81 

12/16/81 

367 21 1 182 I 

2:05 2:05 FAATC NewILS Update 

0:40 0:oo FAATC NewILS Update 

1:20 0:OO PIED. Maintenance 

0:40 O:oo LRC Maintenance 

~ 
Date rota1 Flight Time Research Flight Time Test Site Flight Test Objectives 

Maintenance 

Pilot Proficiency 

Flight # 

368 6/16/82 0:40 O:oo LRC 

369 6/22/82 1:20 0:oo LRC 

370 

37 1 

37 1 

1:20 0:00 LRC Maintenance 

7130182 0:oo STEP 

- 

WFF 

WFF 

WFF 

0:35 

1:45 

035 

~~ 

STEP 

STEP 

7130182 1:45 

7130182 

8/5/82 

371C 0:oo 

372A 0:40 O:oo WFF STEP 

372B 8/5/82 l:oo 1:oo WFF STEP 

372C 8/5/82 1:20 1 :20 WFF STEP 

372D 8/5/82 

8/ 10/82 

81 10182 

81 10182 

81 17/82 

81 17/82 

81 I 7/82 

81 17/82 

8/24/82 

8/24/82 

8/24/82 

8/24/82 

9/2/82 

9/3/82 

9/7/82 

91 818 2 

9/8/82 

918 I8 2 

9/8/82 

91 XI 8 2 

91 14/82 

91 14/82 

9/14/82 

91 14/82 

~~~ 

~ ~ 

~- 

~- ~ 

~~ 

-- ~ 

_____~ 

~__~ 

-~ 

~~~ 

~- 

~- 

~- - 

-- 

~- 

~- 

~ 

o:20 

o:40 

0: IO 

1 :05 

]:I5 

0:50 

0:30 

2:20 

1 :40 

0:35 

~ 

~ ~~ ~ 

~ 

~~ 

9/14/82 

91 14/82 

9/23/82 

9/23/82 

9/23/82 

91 231 8 2 

‘)I2818 2 

9/28/82 

1) 12 81 8 2 

0/28/82 

1 Ol5IX’ 

10/5/82 

10/5/82 

~-~ 

~- 

~- 

-~ 

~ 

0:20 

250 

2:45 

0:55 

0:50 

2:05 

1 :05 

0:oo 

1 :05 

Airhorrir Tr/rilhhzrr 
38% 11/10/82 0:40 0:oo WFF 1 STEP 

390 11/23/82 1 :20 0:oo LOCAL Pilot Proficiency 

391A 11/30/82 0:40 0:25 WFF STEP 

391B 1 1130182 2:oo 2"OO WFF STEP 

391C 11/30/82 2:50 2:25 WFF STEP 

391C 11/30/82 0:20 0:oo WFF STEP 

392A 12/7/82 0:15 0:oo WFF STEP 

392A 12/7/82 0:45 0:45 WFF STEP 

392B 12/7/82 0:15 0:15 WFF STEP 

392C 12/7/82 255 2:55 WFF STEP 

392C 12/7/82 0:50 0:oo WFF STEP 

393A 12/9/82 0:15 0:oo WFF STEP 

393A 12/7/82 1:45 1:45 WFF S'I'EP 

393B 12/9/82 3:05 3:05 WFF STEP 

393c 12/9/82 0:45 0:oo WFF STEP 

~~~__

______

~~~~ 

~~ ~ 

~~~~~ 

394A 12/14/82 0:15 0:oo 

394A 12/14/82 2:40 2:40 WFF STEP 

394B 12/14/82 2:30 2:30 WFF STEP 

394B 121 14/82 0:45 0:oo WFF STEP 

395A 1 1/11/83 0:20 0:oo WFF STEP 

~ ~~ 
_~ ~ 

Flight # 

395A 

Date I Total Flight Time I Research Flight Time 

111 1/83 I 2:30 I 2:30 

rest Site 

WFF 

395B WFF 

395c 

395c 

396A 

396A 

396B 

396C 

397A 

397A 

397B 

398A 

398A 

398B 

398C 

398D 

398D 

399A 

399A 

399B 

~- 

-- ~ 

- ~- 

~~ - 

P- ~ 

~__ - 

-- - ~ 

___ 

-~ ~ 

399n ~ 

400A 

400A 

400B 

400C 

400C 

401A 

401A 

401 R 

401C 

40 1 c 

402A 

402A 

____ - 

- P___- 

-- 

- 

- - 

-_ 

~ ~~ 

~~ 

~-P 

4o2n P_- 

40213 

403A 

403A 

403A 

40311 

403c: 

404A 

40411 

404c: 

404 1) 

4041: 

404t, 

-~ _ 

- _ 

~ 

111 1/83 2:40 2:40 

111 1/83 0:15 0:15 

111 1/83 0:30 0:00 

1/25/83 0:20 0:00 

1/25/83 2:40 2:40 

1/25/83 2:00 2:00 

___ 2/8/83 

2110183 

21 10183 

21 1 5/83 

21 15/83 

21 15/83 

21 I 51x3 

2/24/83 

2/24/83 

2/24/83 

2/24/83 

2/24/83 

3/3/8 3 

31 31 x.3 

31 31 8 3 

3/3/83 

3/3/83 

3/3/83 

~~ - 

~ __ 

~ 

~ 

-- - 

~- 

~_ 

- 

-_ 

- 

2:25 

0:15 

0:15 

2:55 

2:55 

0:40 

0:20 

295 

0:35 

1 :20 

~- 

~ ~_ 

~ ~ 

_- 

~ -~ 

P~ 

~~ 

0:55 

0:40 

~ 

1 :05 

1 :20 

I :45 

~ 

1:lO 

0: 15 

~ 

WFF 

WFF 

WFF 

WFF 

WFF 

WFF 

WFF 

WFF 

WFF 

WPlWFF 

- 

- -~ 

_ 

-_ 

- 

WFF -_ 

WFF 

WFF 

WFF 

WFF 

WFF 

W1.F 

~~ 

~ 

-~ 

- 

WFF 

WE’F 

WFF 

WFF 

_ 

Flight Test Objectives 

STEP 

STEP 

STEP 

STEP 

STEP 

STEP 

STEP 

STEP 

STEP 

166 Airborne Trnilbhzt>r 
I Flight # Date 

404E 1 3/3/83 

Total Flight Time Research Flight Time Test Site Flight Test Objectives 

0:20 0:20 WFF STEP 

405A 

405B 

405B 

405C 

405C 

406A 

- 406B .- 

406C 

406C 

406D 

406E 

407A 

407B 

408 

____ 

0:05 -- 

3/22/83 0:15 0:15 WFF STEP 

3/22/83 0:15 0:15 WFF STEP 

3/22/83 0:20 0:20 WFF Open Loop Upgrade 

3/22/83 0:15 0:15 WFF STEP 

3/22/83 0:40 0:40 WFF STEP 

3/23/83 0:40 0:40 WFF GAPAN Nav Demo 

3/23/83 0:20 0:20 WFF GAPAN Nav Demo 

3/23/83 0:20 0:20 WFF GAPAN Nav Demo 

3/23/83 0:30 0:30 WFF GAPAN Nav Demo 

3/23/83 0:30 0:30 WFF GAPAN Nav Demo 

3/23/83 0:20 0:20 GAPAN Nav Demo 

_____

I 3 13 0 18 3 0:30 0:oo WASH STEP 

3130183 0:35 0:oo LRC STEP 

6/13/83 1 :20 0:oo WFF A/C Grd Hdlg Tests __ -_ 

1 FAATC 1 A/C Grd Hdlg Tests t- -- - 

409A I 6/15/83 --__- 

, 

I 413R 6/23/83 0:30 0:30 FAA'K 1 A/C Grd Hdlg 'I'ests 

- 0:15 0:oo WFF A/C Grd Hdlg Tests _____ 

409A I 0:05 

409B ~ 6/15/83 0:lO 

409C 6/15/83 0:10 

407D 6/15/83 0:05 

409D 61 15/83 0:15 

410A 61 17/83 0:15 

~- 410A i 6/17/83 0:05 

410B 1 6/17/83 0:lO 

410C ' 6/17/83 

____________. 

______ 

O:oo WFF A/C Grd Hdlg Tests 

0:lO WFF A/C Grd Hdlg Tests 

0:lO WFF A/C Grd Hdlg Tests 

0:05 WFF A/C Grd Hdlg Tests 

0:oo LRC A/C Grd Hdlg Tests 

0:oo WFC A/C Grd Hdlg Tests 

0:05 WFC A/C Grd Hdlg Tests 

0:lO WFF A/C Grd Hdlg Tests 

________________________~ 

I___ 

__________ ____ 

-.__-_________ __ - -- 

__ ______ 

___ __ _____ 
Date ‘ZalFlight Time Research Flight Time Flight Test Objectives 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

A/C Grd Hdlg Tests 

Main re tiance 

Maintenance 

I 

- - 

~~ 

~- ~ 

-_ ~ - 

__ ~ - ~ 

- 

6/24/83 0:50 0:50 

6/24/83 0:15 0:15 

0:15 

0:15 

6/24/83 0:15 

6/24/83 0:15 ;MTC 

6/24/83 0:05 0:05 

6/24/83 0:05 0:05 :AATC 

6/24/83 0:30 0:00 ,RC 

6/28/83 0:15 0:00 VF F 

6/28/83 0:10 0:10 

0:40 

Maintenance 

Open I,mp Upgrade 

Open Loop Upgrade 

‘I’SRV Flt Verif’l’ests 

TSRV Flt Verif Tests 

‘I’SRV Flt Verif Tests 

’I’SRV Flt Verif ’I’ests 

TSRV Flt Verif Tests 

RV Flt Vcrif l‘csts 

’I’SRV Flt Vcrif’l‘csts 

’I’SRV Flt Vcrif’l’csts 

‘I’SRV Fit Verif’l’ests 

- ~~~ ~ ~ - 

~~ .~ ~ ~~~~ 

- ~~ ~ ~~ - ~~~ 

~~~ - ~ -~ 

. - 

~ ~ 

~~ ~ ~ - 

~ -~ ~ ~ 

~~ - 

- 

~- 

-~ 

- ~ ~~ 

.fSRV Flt Vcrif Tests 

’I‘SKV Fit Verif’l’csts 

- ~ ~~ 

~~ - 

~- 

RV Flt Verif ’l‘ests 

AIC: (;rd Hdlg ’I’csts 

A/<: (;rd Hdlg ’I’ests 

- 

~ ~ - 

42513 

42 5 13 

426A 

- 

42613 

426C: 

4261) 

4261- 

427A 

4271% 

428A 

42813 

429 

430 

4.3 1 

432 

433.4 

- 

1 1/20/84 

1 1/20/84 

1 1/28/84 

1 1/28/84 

- 

~ 

-~ 

I2/3/84 

1 21 IX/X/t 

2/5/85 

.3/6l85 

3/7/85 

3/8/85 

3/9/85 

I :oo 

0: 5 5 

0:oo 

1 :25 

0:20 

~ 

0:oo 

0:oo 

0:20 

0:3o 

0: 15 

~ 

~ 

0:30 

0: 15 

168 
443c 

- 443D 

443E 

7/11/85 2:30 2:30 WFF Airport 85 Program 

711 1/85 1:40 1 :40 WFF Airport 85 Program 

711 1/85 0:35 0:10 WFF Airport 85 Program 

__________________~

___ 443F 1 7/11/85 0:40 0:oo LRC ____ Airport - 

85 Program _- - - _____ 
~~ 

Date I Total Flight Time Research Flight Time rest Site Flight Test Objectives 

Airport 85 Program 

Flight # 

446C - 71 17/85 o:2o A/& 1:5O 

0:oo WF F .~ u _I__~

Airport 85 Program - 

______ Airport 85 Program 

Airport 85 Program 

Airport 85 Program 

Airport 85 Program 

Airport 85 Program 

Airport 85 Program 

Airport 85 Program 

~__ 

-__~_______ ____- 

____ -~ - - 

__ 

~ ___-_ - 

________ 

__ 

0:oo DEN 

DEN 

DEN 

447A 

447B 7/28/85 I 2:oo 

448A 7/31/85 ! 2:45 

81 1/85 1 :40 

- 

449A DEN 

449B 8/1/85 1 :oo DEN 

450 8/2/85 3:15 3:15 

45 1 8/3/85 I 3:00 3:oo 

1:1o - 452A 

452B 

453A 

453B 

454A 

45413 

455A 

455A 

455B 

456A 

456B 

456C 

4561) 

457A 

457B 

458A 

45813 

45HC 

459A 

459R 

46OA 

460 R 

461A 

461 13 

461 13 

46113 

462A 

462B 

462C 

462C 

403 

464 

405 

400A 

-__- - 

___ - 

~ 

-- 

__ 

-- -- 

- - ~- 

__~ - 

~ _~ 

-___ - 

- ~ - 

_- - 

-- 

-- - 

_~ ~- 

~__ 

_~- 

-- 

-- 

- 

- 

Airport 85 Program 

Airport 85 Program 

- 

- Airport 85 Program 

Airport 85 Prograni 

Airporr 85 I’rogram 

~- -_ - - - 

-- - - 

~- ~ -~ 

‘Total Energy Ctl Sys ~ -- 

Total Energy Crl Sys 

TSRV Flt Verif Tests 

-- - 

-~ ~- ~ ~ - 

TSKV Flc Verif Tests 

Total Energy Ctl Sys 

Total Energy Ctl Sys 

’I’SKV E’lt Verif Tests 

Total Fhergy Ctl Sys 

TSliV Flt Vcrif’l’csts 

- 

~ -- 

-- - 

~- __ ~- ~- 

~~ ~~ ~ ~ ~. ~ 

- ~~ - ~. - 

I‘SKV Flt Verif Tests 

TSKV Flt Verif’Tests 

Total Energy C:tl Sys 

~~~ 

~ -. 

~~ 

Total Fmcrgy <:tl Sys 

l’otal Energy Ccl Sys 

local Energy <:tl Sys 

__ 

~~ 

- - 

-~ ’l’otal E‘,nergy Ctl sys ~~ - - 

WFF 

I .OCA 1 

LOCAL. 

LOCAL 

1.C)CAl 

1 OCAI. 

Wtl‘ 

WIT 

WI+ 

- 

5/ 12/87 I 0:20 

I 

5/ 15/87 1:35 

(>I 21 87 

~ I 2:oo 

- 

I :50 

0:45 

2:I5 

1:50 

- 

46713 

468A 

- WFF 

WFF 

Airborrrr Triiilbkizrr 
Flight # 

468B 

469A I I 

469B 61 15/87 WFF Director Demo 

Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

611 1/87 2:05 2:05 WFF Director Demo 

61 15/87 1:lO 1:lO WFF Director Demo 
~~ ~ 

Date 

12/17/87 

Flight # rota1 Flight Time Flight Test Objectives 

0:3O 

1:18 

Research Flight Time 

0:30 

1:18 

*est Site 

489D VF F Demo 

489E 1211 7/87 VFF MLS Performance 

489F 121 17/87 O:oo .RC Ferry to LRC ~ 

111 9/88 

1/19/88 

.- 4890 2:oo KIF F LEBU Data Flight 

LEBU Data Flight 

LEBU Data Flight 

LEBU Data Flight 

LEBU Data Flight 

LEBU Data Flight 

LERU Data Flight 

Pilot I'roficicncy 

LERU Data Flight 

______- 

~__ 

______ __~-___~- 

~____ 

~ - ~- 

~ -~ - - 

-~ ~ 

- 

~ ~_ 

I+erry to lXC 

Ferry to WFF 

TOI'MS 'rebt\ 

Ferry to WFFIRNAV 

RNAVlMLS Run\ 

~_

~ 

~ 

~- - 

2:oo WFF 

1 11 3/88 1:30 1:12 WF F 

WF F 

____ 490B 

49 1 2/5/88 2:18 

2:48 

2:42 

~ 

~____ 

2:18 

492 21 1 1 188 2:36 WFF 

2/22/88 

2/26/88 

3/7/88 

3/7/88 

3/7/88 

3/8/88 

31 1 5/88 

311 5/88 

311 5/88 

3/22/88 

3/22/88 

3/24/88 

3/24/88 

3 / 29 / 8 8 

3/29/88 

4/5/88 

4/5/88 

4/6/88 

4 IO/ 88 

4/O/8 8 

4/7/88 

4/21 188 

4/26/88 

6/30/88 

6/30/88 

6/.30/88 

7/7/88 

7/7/88 

7/7/88 

71 14/88 

71 14188 

71 14/88 

7/25/88 

7/25/88 

7/25/88 

5 / 2 / 8 0 

5/2/89 

5/4/80 

~ _____ 

~- 

~ - 

~- 

~- 

- ~- 

- - 

~ 

~ 

~ - 

- 

~ 

~~ 

493 2:42 

4 94 4:OO 

495 

436A 

496R 

497 

498A 

49813 

498C 

499A 

493R 

50OA 

50013 

SOIA 

50 1 I3 

502A 

50213 

SOJA 

50313 

503c: 

504 

505 

500 

507 

508A 

5081< 

509A 

509 13 

500(: 

510A 

5 1 OH 

5 1 OC' 

51 1 

51214 

5121< 

5 1 9 

520 

52 1 

__ 

~ 

~~ 

~ 

- 

~ 

~ 

-_ 

~ 

~ 

~ 

O:42 

0:30 

1 :54 

2:54 

030 

2:12 

0:30 

2:OO 

2:12 

2:18 

1 :30 

O:18 

0: 1 8 

1 :42 

0:54 

2:oo 

1:12 

1 :30 

2:18 

7:oo 

3:oo 

0: 12 

1 :24 

2:12 

1:18 

0:36 

2:18 

1 :oo 

1 :42 

0:54 

0:oo 

.3:24 

I :24 

0:42 

242 

2:oo 

~~ 

~~ 

- 

~ 

- 

~ 

~~ 

~ 

~~ 

~ 

~ 

~ - 

~ 

1:18 

0:oo 

0:oo 

0:OO 

~ 

- ~- 

0: 12 

2:oo 

1:12 

0:OO 

I :24 

2:12 

I:18 

0:36 

2:18 

I :oo 

1 :42 

0:54 

0:06 

.3:24 

1 :24 

0:oo 

2:42 

2:oo 

~ 
539 I 11/13/89 

540 11 / 17/89 

54 1 1 11/20/89 

542 I 11/29/89 

I 

5:18 5:18 ' WFF IR WndshdTOPMS 

1:oo 

2:30 2:30 WFF ~ Data LinWIR Wndshr 

3:36 3:36 WFF 1 Data LinWIR Wndshr 

0:oo LRC Maintenance 

543 1 12/5/89 

544 121 14/89 

545 3/27/90 

546 3/27/90 

4/5/90 

4/ 12/90 

549 4/ 19/90 

550 4/24/90 

51- 4/27/90 

552 1 5/1/90 

I 

- 

553 I 5/4/90 

554 5/8/90 

555 511 5/90 

556 513 1/90 

557 513 1 190 

558 I 6/7/90 

559 611 1/90 

560 61 12/90 

-____t 

I ~ -~ ____ 

--__t_- 

I 

4:24 4124 WFF LCWSlEMACS 

2:54 2:54 WFF Data LinklIR Wndshr 

1 :36 0:oo LOCAL Maintenance 

3:18 3:18 WFF Flt VerifIData Link 

506 5:06 WFF Flt Grif/IR Wndshr 

306 3:06 WFF Data Link 

4:30 430 WFF Data Link 

3:30 3:30 WFF Data Link 

340 3:40 WFF Data Link 

3:24 3:24 WFF Data Link 

4:OO 4:OO WFF Data Link 

4:12 4:12 WFF Data Link 

~___~___

~~~~ 

2:42 1 WFF I EMACS 

0:OO 1 1,OCAL ~ 1 Maintenance - -4 

I 

_t 

~ -__ 3:OO 3:OO WFF 1 EMACSIIR Wndshr 

1 40 1 :no 

l:oo 

1 :48 1 -~ ~ High Lift 

I Data Link ___ _~_________ 

--- 

JLOCAL 

TG ~- .____ 

__ 1 :48 JWFF _______ 

2:oo Data Link 

4:30 

1 :30 

3: 18 1 3:48 

0: 12 0:OO 

3:36 

61 15/90 - 561 

562 --'- 6/18/90 

563 1 6/20/90 1 :30 

5 64 612 1/90 3:18 

565 6/27/90 

566 6/29/90 

567 6/29/90 

_____~- _~~_____- 

ata Link 

~~ __~~- 

__~___ 1 WFF -~ ~- -~ - -~ __ ~ 

I _________ 

__~_ __- 

I I -~ -t ________ 

WFF 1 Data Link 

-- ~~ -~ 

I 3:36 
Date Flight Test Objectives 

Data Link 

FMNASA ATOPS Demo 

rota1 Flight Time Research Flight Time Test Site 

3:24 WFF 

5:00 I WFF1D.C. 

0:00 LOCAL 

412 WFF 

3:12 WFF 

2:36 WFF 

1:42 WFF 

4:48 WFF 

4:30 WFF 

4:24 WFF 

3:56 WFF 

Flight # 

568 

569 

I 

7/2/90 3:24 

7/6/90 5:00 

Maintenance 570 912 1 I90 1:54 

57 Flt Verif Tests 1 9/24/90 4:12 

10/2/90 

101 10/90 

- 

3:12 GPSIINS Autolnd 5 72 

573 2:36 GPS AutolndIIn Situ Wndshr 

574 10/18/90 1:42 GPS AutolndIIn Situ Wndshr 

575 10/24/90 4:48 GPS AutolndIIn Situ Wndshr 

576 10/30/90 430 GPS Autolnd/In Situ Wndshr 

577 GPS AutolndIIn Situ Wndshr 

GPS AutolndIIn Situ Wndshr 

5:00 I WFF GPS AutolndIIn Situ Wndshr 

GPS AutolndIIn Situ Wnd\hr 

EMACSlHgh Spd Turnoff 

Maintenwce 

H h S d TurnoffIIR Wndshr 

~ - ~ ~~ 

- 

- ~ ~~~ - ~ - 

-~~ ~ ~~ ~ ~ 

- _P ~ - 

Hgh Spd Turnoff -_- ~ 

High Lift 

Pilot Training 

EMACS 

Radar Windshear 

Radar11 R Wndshr 

Radar/IR Wndshr 

liadarllli Wndshr 

RadarIlR Wnclshr 

Kadarllli Wndshr 

Kndarl I li W ndsh r 

EMACS 

Maintenancc 

High I.ift 

M ai 11 t c n :in cc 

High l.ift/GPS 

- ~~. - ~ - 

- - 

___ ~ - 

- ~ 

- 

~~- 

- ~ ~ 

- 

~- - 

~ 

-~ ~~ ~ - 

- ~ 

~- 

WindshearIFlt Verif 

Windshcar/(;l'S 

Windshear 

Windshcar/l.OIiAN 

Windshear 

Windshear 

W indshcar 

Windshear 

Windshear 

W i ndshear 

~~ 

~ ~ ~~ ~ 

~ ~~ ~ ~. 

~~ ~~ ~ 

~- ~ ~ 

~~ 

~~~ 

~ 

612 

613 

I74 Airborne Trtrilhhzer 
Flight # 

614 

64 5 

616 

617 

618 

619 

____ 

Date Total Flight Time Research Flight Time Test Site Flight Test Objectives 

7/7/91 4:12 412 LRC FerryICali bration 

7/8/91 1 :oo 1 :oo Denver Exp Sys C/O 

71919 1 0:54 0:54 Denver Windshear 

7/10/91 2:06 2:06 Denver Winds hear 

7/11/91 1:54 1:54 Denver Windshear 

7/13/91 2:30 2:30 Denver Windshear 

- 

620 71 17/91 3:48 3:48 Denver Windshear 

62 1 71 1819 1 1:06 1:06 Denver Windshear ~~__________~ 

I 632 1 2/27/92 I 2:24 I 2:24 I FAATC 1 ILSModeling/LIDk 

622 

623 

624 

625 

626 

712019 1 0:30 0:30 Denver Windshear 

712619 1 4:06 4:06 Denver FerrylCalibration 

8/12/91 1:42 0:oo LRC Ferry to AL 

912319 1 2:24 0:oo BHM, AL Ferry to LRC 

1/31/92 1 :30 0:oo WFF Maintenance 

~~~~~ 

627 1 2/3/92 

628 2/7/92 

629 2/10/92 

630 2/12/92 

63 1 2/27/92 

0:54 0:54 LRC Flt VerifIHigh Lift 

3:30 3:30 LRC Flt VerifIHigh Lift 

3:12 3:12 WFF High Lift 

6:36 6:36 WFF High Lift 

l:oo 0:oo LRC Maintenance 

633 3/4/92 

634 3/25/92 

635 3/25/32 

636 3130192 

637 3/31/92 

638 4/1/92 

639 4/2/92 

640 4/4/92 

64 1 4/27/92 

642 5/13/92 

643 6/24/92 

644 6/24/92 

645 ' 6/26/92 

646 6130192 

647 6130192 

648 7/2/92 

649 7/9/92 

650 

65 1 7/14/92 

____ --I 

--- I 

____ ! ?I 13/92 

____ 

4:30 4:30 PHFIFAATC ILS ModelingIMLSlDGPS 

1:12 0:oo LRC Maintenance 

2:42 2:42 LRC ILS ModelingILIDAR 

5:48 0:oo LRC Ferry to LAX 

3:12 3:12 LAX ILS ModelingILIDAR 

4:OO 4:OO LAX ILS ModelingILIDAR 

4:OO 4:OO LAX ILS ModelingILIDAR 

5:30 0:oo LAX Ferry to LRC 

1 :42 0:oo LRC Ferry to BHM, AL 

2:12 0:oo BHM, AL Ferry to LRC 

130 0:oo LRC Functional Tst Flt 

4:06 4:06 WFF Flt Verif Tests 

3:48 3:48 WFF Flt VerifIWindshear 

1:12 0:oo WFF Functional Tst Flt 

3:24 3:24 WFF Flt VerifIWindshear 

3:18 3:18 WFF Flt VeriflWindshear 

1 :42 0:oo LRC Functional Tst Flt 

-~ 

~_________

_______________ 

- _____ ~ ~~ 

4:12 4:12 LRC WindshrlFerry to DEN 

2:30 2:30 Denver Windshear ~ 

652 ?I 15/92 1:54 1:54 

653 ?/ 18/92 1:18 1:18 

654 7120192 1:36 1:36 

655 712 1 I92 1:54 1:54 

656 7/22/92 1 :48 1:48 

2:18 2:18 

658 7/24/92 3:48 3:48 

659 I 81 10192 1:48 1:48 

I 

__I__, 

I 

~~~ 

Denver Windshear 

Denver Windshear 

Denver Windshear 

Denver Windshear 

Denver Windshear 

Denver Windshear 

Denver I WindshrIFerry to LRC 

LRC WindshrIFerry to LRC 
Date Flight Test Objectives 

Windshear 

Windshear 

Research Flight Time 

~ 

- 

~~ 

rest Site 

lrlando 

lrlando 

Flight # ’otal Flight - Time 

1 :48 - 

660 811 1/92 1:48 

8/12/92 230 2:30 

2:06 

66 1 

662 

663 

81 13/92 2:06 Mando Windshear 

1:36 

1:48 

1:36 

1 :48 

.__ - Mando 

lrlando 

__ - 

Windshear 

Windshear 

__ ~~___ 81 14/92 

664 811 5/92 

8/ 17/92 

81 19/92 

8120192 

- 

~- 

665 1 :42 1 :42 Mando 

2:06 lrlando 

3rlando 

-_ 666 

667 1:48 

668 8/21/92 1:54 

669 

670 

67 1 

672 

673 

674 

(175 

676 

677 

678 

679 

680 

68 1 

682 

(’83 

684 

68 5 

086 

687 

088 

689 

690 

69 I 

092 

603 

004 

605 

696 

607 

6% 

0 9 9 

700 

70 I 

702 

~ 

~ 

~~ 

~ 

~ ~ 

~~ 

~ 

~ 

~ 

~ 

10/28/92 

1 1 /2/02 

1 1 /0/92 

1 1 I1 2/92 

4/zo/9 z 

4 I 3 0 IO 3 

5/(J9.3 

5/20/93 

5/25/93 

5 I 28/03 

~~ 

~ 

0:oo 

2:42 

3: 18 3:18 

1 :4H 1 :48 

3:oo 

3:42 

542 

~ 

.i :0 0 

542 

3:42 

1:12 

61 10193 

6/28/93 0:oo 

7/7/03 2:48 

712 1/93 

~~ 

2:48 

O:$O 0:oo 

1 :42 Ilt Vcrif’I‘csts 

3:24 

~ 

1 :42 

3:24 

2:12 

524 

4:54 

3:l8 

2:12 

3:24 

4:54 

.3: 1 H 

Airborne 7 rzilbhzer 
Acknowledgements 

n researching and writing this history, I had I the advantage of being able to talk directly to 

many of the people who organized and managed 

the original Terminal Configured Vehicle/ 

Advanced Transport Operating Systems program 

and the researchers and engineers who 

conducted its many research projects. Many 

active and retired NASA engineers donated 

generous amounts of their time to educate me 

about their work and the airplane’s history and 

sent me copies of their personal notes and other 

printed material that was invaluable in piecing 

together this story. In addition, I am indebted to 

the numerous active and retired managers, 

engineers, and representatives from the Federal 

Aviation Administration, the Lockheed 

Corporation, the Boeing Commercial Airplane 

Company, the McDonnell Douglas 

Corporation, Honeywell, Inc., the Collins 

Commercial Avionics division of Rockwell 

International, and ARNAV Systems, Inc., who 

took the time to talk with me about research 

projects conducted with NASA’s 737 and 

commercial applications the research influenced. 

The managers, public relations staff, and 

historians at Boeing also donated critical notes 

and photographs pertaining to the airplane’s preNASA history and the early years of the TCV 

program. Without the information and 

assistance provided by all these people, this book 

could not have been written. 

As the project progressed, the Langley 

Research Center staff also cheerfully answered 

the dozens of follow-up questions I had and 

willingly reviewed drafts to ensure the technical 

accuracy of the information being presented. In 

fact, throughout the course of this project, I 

received an immense amount of cooperation, 

assistance, and information, all of which was 

greatly appreciated. Once the manuscript was 

completed, there were also many people, too 

numerous to mention by name, who helped with 

the editing, design and layout of the book, and 

shepherded the project through its publication. 

Their efforts are evident on every page, and I am 

grateful to all of them. 

I owe a special note of thanks, however, to 

Sandra Mims of the Advanced Transport 

Operating Systems office, who spent an 

enormous amount of time tracking down 

information, people, and obscure but critical 

documents, and even shared her office, her desk, 

and some days even her lunch with me to get 

this project finished. 

Index 

Abbott, Terence S.: 83 

Advanced Digital Electronic Displays: 13 

Advanced Transport Operating Systems (ATOPS) 

Program: 7, 9-23; acquires Boeing 737, 11-14; 

and aircraft operations research, 89-103; and 

aircraft systems research, 75-87; and Airport 85 

research, 114-16; and Boeing 737 research 

systems, 14- 18; and cockpit computerization, 

36-39; and cockpit displayed traffic information 

research, 93-94; and computerization and 

electronic flight displays research, 25-39; and 

data link research, 95-99; and digital access 

communication research, 75, 76-78; and 

electronic flight display research, 27-33; and 

engine monitoring and control system, 75, 

83-85, 120; and global positioning system 

research, 50-53, 102, 120, 122; and helmet 

mounted display research, 112-14; and high lift 

research, 108-109; and instrument landing 

system signal modelling research, 1 16- 17; and 

large eddy break-up research, 108- 109; and 

microburst windshear research, 55-73; and 

magnetic cable guidance research, 10 1-1 02; and 

microwave landing system, 1 1, 15, 2 1, 27, 34, 

41-53, 120, 121; optical propulsion management 

interface, 78-80; and precision flare laws research, 

99-101; and profile descent research, 90-93; 

program organization, 18-23; and runway 

friction research, 109-12; and takeoff 

performance monitoring system, 75,76, 85-87; 

and technology transfer, 1-7, 33-36; and total 

energy control system, 75, 81-83, 120; and wing 

surface coatings research, 106- 107 

Aeronautical and Space Sciences Committee (Senate): 9 

Aeronautical Radio, Inc.: 78, 80, 95 

Aeronautics: aircraft operations research, 89- 103; aircraft 

systems research, 75-87; Airport 85 research, 

114-16; Boeing 737 research systems, 14-18; 

cockpit computerization, 36-39; cockpit 

displayed traffic information research, 93-94; 

cockpit technology, 5; computerization and 

electronic flight displays research, 25-39; data 

link research, 95-99; digital access 

communication research, 75, 76-78; electronic 

flight display research, 27-33; engine monitoring 

and control system research, 75, 83-85, 120; flyby-wire technology, 4; global positioning system 

research, 50-53, 102, 120, 122; helmet mounted 

display research, 112-14; high lift research, 

108-109; instrument landing system signal 

modelling research, 1 16- 17; microburst 

windshear research, 55-73; large eddy break-up 

research, 108-1 09; magnetic cable guidance 

research, 10 1-1 02; microwave landing system, 

11, 15, 21, 27, 3441-53, 120, 121; optical 

propulsion management interface, 78-80; 

precision flare laws research, 99-1 0 1; profile 

descent research, 90-93; runway friction research, 

109-1 2; takeoff performance monitoring system 

research, 75,76, 85-87; technology transfer and, 

1-7, 33-36; total energy control system research, 

75, 81-83, 120; wing surface coatings research, 

in(;-in7 

Aeronautics Steering Committee, Langley Research 

Aeroparque Jorge Newbery: 47-48 

Airborne Windshear Detection and Avoidance 

Program: 61 

Airbus A-3 10: I 08 

Airbus A-320: 14, 108 

Airbus Industries: 4, 108 

Air Florida Airlines: 84, 109, 1 10 

Air Force, United States: 84, 86, 114-16, 117, 120 

Airport 85, Project: 114-16 

Air Route Traffic Control Centers: 90, 91 

Air Transport Association: 38, 5 1, 98 

All Weather Operations Panel: 42,44,49 

Allied Signal Corp.: 72 

Aloha Airlines: 70 

American Airlines: 61 

Ames Research Center: 11, 38, 92 

Apollo, Project: 9, 123 

Center: 10 
Armstrong, Neil A.: 9 

ARNAV Systems, Inc.: 85 

Ashtech, Inc.: 52 

Automatic Guidance and Control System: 13 

Avionics Research: 10, 25-39, 75-87; and advanced digital 

electronic displays, 13; and aircraft operations 

research, 89-103; and aircraft systems research, 

75-87; and Airport 85 research, 114-16; and 

automatic guidance and control systems, 13; and 

cockpit computerization, 36-39; and cockpit 

displayed traffic information research, 93-94; and 

computerization and electronic flight displays 

research, 25-39; and data link research, 95-99; 

and digital access communication research, 75, 

76-78; and electronic flight display research, 

27-33; and engine monitoring and control 

system research, 75, 83-85, 120; and global 

positioning system research, 50-53, 102, 120, 

122; and helmet mounted display research, 

112-14; and instrument landing system signal 

modelling research, 116-17; and large eddy 

break-up research, 108- 109; and microburst 

windshear research, 55-73; and magnetic cable 

guidance research, IO 1- 102; and microwave 

landing system research, 1 1, 15, 2 1, 27, 34, 

41-53, 120, 121; optical propulsion management 

interface, 78-80; and precision flare laws research, 

99- IO I ; and profile descent research, 90-93; and 

runway friction research, 109- 12; and takeoff 

performance monitoring system research, 75, 76, 

85-87; and technology transfer, 1-7, 33-36; and 

total energy control system, 75, 8 1-83, 120 

Basnett, Michael: 7 1 

Bendix Corp.: 43, 72 

Boeing Advanced Guidance and Control Panel: 15 

Boeing Commercial Airplane Co.: 4, 6, 12, 13, 14, 18, 

20, 33-35, 38. 61. 63, 75, 77, 81, 89, 90, 92, 

100, 106, 107, 120, 122 

Roeing Computer Services: 33 

Boeing 727 Aircraft: 10, 56, 59, 106, 110 

Boeing 737 Aircraft: 2, 7, 11-12, 75, 84; acquired, 11-14; 

research systems, 14- 18; and aircraft operations 

research, 89-1 03; and aircraft systems research, 

75-87; and Airport 85 research, 114-16; and 

cockpit computerization, 36-39; and cockpit 

displayed traffic information research, 93-94; and 

computerization and electronic flight displays 

research, 25-39; and data link research, 95-99; 

and digital access communication research, 75, 

76-78; and electronic flight display research, 

27-33; and engine monitoring and control 

system, 75, 83-85, 120; and global positioning 

systcm research, 50-53, 102, 120, 122; and 

helmet niotitited display research, I 12-14; and 

high lift research, 108-109; and instrument 

landing system signal modelling research, 

1 16-1 7; and microburst windshear research, 

55-73; and large eddy break-up research, 108- 

109; and magnetic cable guidance research, 

101-102; and microwave landing system, 1 I, 15, 

21, 27, 34,41-53, 120, 121; optical propulsion 

management interface, 78-80; and precision flare 

laws research, 99-101; and profile descent 

research, 90-93; program organization, 18-23; 

and runway friction research, 109-12; and takeoff 

performance monitoring system, 75,76, 85-87; 

and technology transfer, 1-7, 33-36; and total 

energy control system, 75, 81-83, 120; and wing 

surface coatings research, 106-107 

Boeing 747 Aircraft: 33, 37, 10 1 

Boeing 757 Aircraft: 21, 33, 35, 38, 39, 101, 122 

Boeing 767 Aircraft: 21, 33, 35, 37, 39, 92, 101, 122 

Boeing 777 Aircraft: 82, 87, 99 

Bond, Langhorne M.: 47 

Boston, MA: 109 

Bowles, Roland L.: 60, 6 1, 62, 7 1 

British Aerospace (HS) 748 Aircraft: 49 

Brown, George: 59-60 

Brunswick Naval Air Station, ME: 1 10, 1 1 1 

Brussels, Belgium: 47 

Buckley Air National Guard Base, CO: 1 14 

Buenos Aires, Argentina: 47-48 

C- 14 1A Aircraft: 1 1 

Cape Canaveral, FL: 86 

Civil Aviation Research and Development Policy (CARD) 

Study: 9- 10,42 

Clinton, William J.: 22 

Collier Trophy: 73 

Collins Air Transport Division: 35 

Condor Aircraft: 82-83 

Continental Airlines: 61, 106 

Convair 990 Aircraft: 11 

Control Data Corporation: 14 

Creedon, Jeremiah F.: 21, 60, 73 

Dallas, TX: 55-56, 59, 60, 61, 73, 89, 90, 92, 121 

Dallas/Ft. Worth International Airport: 55-56, 59, 60, 

61,73,90,92 

DC-9 Aircraft: 1 1 

DC-IO Aircraft: 30, 109 

Defense, Department of: 43, 5 1, I I9 

DeHavilland H6-C Twin Otter Aircraft: 44 

Delta Airlines: 55-56, 59, 107. 121 

Denver, CO: 59, 61,67-70, 71, 89, 90, 92, 93, 114, 11 5 

Digital Access Communications: 75, 76-78 

Digital Equipment Corp.: 18 

Eastern Airlines: 56, 57 

Electronics L>irectorate, Langley Research Center: 2 1 

Electronic Flight Displays: 27-33 

Engine Monitoring and Control System: 75, 83-85. 120 

Erzbergcr, Heinz: 92 

txperimental Aircraft Association: 85 

Experimental Avionics Sirnillation and Integration 

Laboratory, Langley Research Center: 77-78 

180 Airborne Trailblazer 
Fadden, Delmar: 33,35,37 

“Fat Albert”: 12 

Federal Aviation Administration: 5, 11, 13, 14, 15, 20, 

35,36,37, 38, 42-50, 53, 55, 56, 57-61,63,70, 

72, 86,89,90, 91,93,94,96,97,98,99, 100, 

102, 103, 105, 109-10, 112, 117, 119, 123 

Flight Control Systems Division: 21 

Flight Experiments Working Group: 20 

Flight Instrumentation Division, Langley Research 

Flight Systems Division, Langley Research Center: 21, 71 

Center: 9 

General Accounting Office: 50 

General Electric Corp.: 17, 18 

Global Positioning System: 50-53, 102, 120, 122 

Global Navigation Satellite System: 53 

Goldin, Daniel S.: 7,22 

Gramm-Rudman Amendment: 22 

Graves, Barry: 9, 10 

Hay, George “Cliff: 60 

Hazeltine Corp.: 50 

Helmet Mounted Display Research: 112-14 

Herzog, Hans: 18, 77, 78 

High Lift Research: 108- 109 

Holmes, David C.: 77 

Howell, William E.: 77 

Hughes, Thomas P.: 3 

Instrument Landing System: 26,41-42, 116-17 

International Civil Aviation Organization: 42,43,44,45, 

46,47, 48, 49, 53 

Jessop, Artie D.: 70, 71 

Joint Airport Weather Studies: 59 

Kansas University: 85 

Kennedy, John F., International Airport: 48, 56 

Kennedy Space Center, John F., FL 86 

Kuhn, Thomas S.: 85 

L-1011 Aircraft: 3, 32, 55-56, 92, 121 

LaGuardia International Airport: 48 

Langley Research Center: 4, 6,7, 9-23, 55; acquires 

Boeing 737, 11-14; Aeronautics Steering 

Committee of, 10; and aircraft operations 

research, 89-1 03; and aircraft systems research, 

75-87; and Airport 85 research, 114-16; and 

Boeing 737 research systems, 14- 18; and Civil 

Aviation Research and Development Policy 

(CARD) Study, 9-10,42; and cockpit 

computerization research, 36-39; and cockpit 

displayed traffic information research, 93-94; and 

computerization and electronic flight displays 

research, 25-39; and data link research, 95-99; 

and digital access communication research, 75, 

76-78; and electronic flight display research, 

27-33; Electronics Directorate of, 21; and engine 

monitoring and control system research, 75, 

83-85, 120; Experimental Avionics Simulation 

and Integration Laboratory of, 77-78; Flight 

Control Systems Division of, 21; Flight 

Experiments Working Group of, 20; Flight 

Instrumentation Division of, 9; Flight Systems 

Division of, 21, 71; and global positioning 

system research, 50-53, 102, 120, 122; and 

helmet mounted display research, 112-14; and 

high lift research, 108-109; and instrument 

landing system signal modelling research, 

1 16-17; and microburst windshear research, 

55-73; and large eddy break-up research, 

108-109; and magnetic cable guidance research, 

101-102; and microwave landing system, 11, 15, 

21, 27, 34,41-53, 120, 121; optical propulsion 

management interface, 78-80; and precision flare 

laws research, 99-101; and profile descent 

research, 90-93; program organization, 18-23; 

and runway friction research, 109-12; and takeoff 

performance monitoring system, 75,76, 85-87; 

and technology transfer, 1-7, 33-36, 119-24; and 

terminal configured vehicle/advanced transport 

operating systems (TCVIATOPS) program, 7, 

9-23; and total energy control system research, 

75, 81-83, 120; and wing surface coatings 

research, 106- 107 

Large Eddy Break-up Research: 108-109 

Lear Siegler Corp.: 28 

Lexington, MA: 46 

Lincoln Laboratory: 46-47, 68 

Litton Corp.: 17 

Lockheed Corp.: 32,61,65 

Lockheed Electra Aircrafi: 10 

Logan International Airport: 109 

Los Angeles, CA 99, 116-17, 120 

Los Angeles International Airport: 116-17, 120 

“Low Altitude Windshear and Its Hazard to Aviation”: 63 

Low, George M.: 9 

Lufthansa Airlines: 12 

McDonnell Douglas Aircraft Corp.: 4, 30,61, 78, 80, 84, 

Mace, William D.: 21 

Magnetic Cable Guidance Research: 10 1 - 102 

Marine Corps, United States: 115, 116 

Massachusetts Institute of Technology: 68, 93 

Microwave Landing System: 11, 15, 21, 27, 34, 41-53, 

Mitsubishi Corp.: 35 

Montreal, Canada: 49 

106, 112-14, 120 

120,121 

National Academy of Sciences: 59, 63 

National Advisory Committee for Aeronautics: 1, 10, 55, 

National Aeronautics and Space Act of 1958: 3 

National Aeronautics and Space Administration: 3, 2 1, 

72, 119, 120 

73; acquires Boeing 737, 11-14; and aircraft 

operations research, 89- 103; and aircraft systems 

research, 75-87; and Airport 85 research, 114-16; 
182 

and Boeing 737 program organization, 18-23; 

and Boeing 737 research systems, 14-18; and 

Civil Aviation Research and Development Policy 

(CARD) Study, 9-10,42; and cockpit 

computerization research, 36-39; and cockpit 

displayed traffic information research, 93-94; and 

computerization and electronic flight displays 

research, 25-39; and data link research, 95-99; 

and digital access communication research, 75, 

76-78; and electronic flight display research, 

27-33; and engine monitoring and control 

system research, 75, 83-85, 120; and global 

positioning system research, 50-53, 102, 120, 

122; and helmet mounted display research, 

112-14; and high lift research, 108-109; and 

instrument landing system signal modelling 

research, 116-17; and microburst windshear 

research, 55-73; and large eddy break-up 

research, 108-109; and magnetic cable guidance 

research, I0 I - 102; and microwave landing 

system research, 1 I, 15, 21, 27, 34, 41-53, 120, 

121 ; optical propulsion management interface 

research, 78-80; and precision flare laws research, 

99-101; and profile descent research, 90-93; and 

runway friction research, 109- 12; and takeoff 

performance monitoring system research, 75, 76, 

85-87; and technology transfer, 1-7, 33-36, 

1 19-24; and terminal configured vehicle/ 

advanced transport operating systems (TCV/ 

ATOPS) program, 7, 9-23; and total energy 

control system research, 75, 81 -83, 120; and 

wing surface coatings research, 106- 107 

National Aerospace Plane: 106, 1 12, 1 13 

National Aviation Facilities Experimental Center: 45, 

National Center for Atmospheric Research: 59, 72 

National Integrated Windshear Plan: 60-61, 72-73 

National Transportation Safety Board: 38, 6 1 

Naval Appropriations Act of 19 15: 1 

Navy, United States: 1 

Newark International Airport: 48 

New York, NY: 48, 56 

New Orleans, LA: 56, 59, 73 

New Orleans International Airport: 56, 59, 73 

Nixon, Richard M.: IO 

Norden Corp.: 17, 18 

Norfolk, VA: 10 

Northwest Airlines: 61, 1 IO 

48,110 

Ohio University: 52 

Optical Propulsion Management Interface: 78-80 

Organization of American States: 47, 48 

Orlando, FL: 67-69, 70, 71 

I’aine, ‘Thorncis 0.: ‘9 

I’m American World Airways: 33, 56, 59, GI 

Person, Lee H.: 68, 115, 116 

Plessy Company, Ltd.: 47 

Pratt and Whitney Corp.: 80 

Precision Flare Laws: 99-1 0 1 

Profile Descent Research: 90-93 

Radio Technical Commission for Aeronautics: 42 

Reagan, Ronald: 1 

Reeder, John: 10, 18, 38 

Renton, WA: 12 

Rickenbacker, Eddie: 33 

Rockwell International Corp.: 35, 65, 72 

Runway Friction Research: 109-1 2 

Saudi Arabian Airlines: 32 

Science Council, White House: 1 

Science and Technology Committee (House): 60, 109-1 0 

Science and Technology Policy, Office of: 1, 10 

Seattle, WA: 12, 33, 35 

Singer Kerflot Corp.: 45 

Smith Industries: 92 

Sperry Flight Systems: 37 

Sperry/Honeywell Corp.: 18, 43, 51, 52.63 

Srivatsan, Raghavachari: 85-87 

Supersonic Transport (SST): 12, 13, 14, 15 

Sydney, Australia: 99 

Takeoff Performance Monitoring System: 75.76, 85-87 

Technology Transfer: 1-7, 33-36, 1 19-24 

Technology Utilization, Office of: 3 

Terminal Configured Vehicle (TCV) Program: 7,9-23; 

acquires Roeing 737, I 1-1 4; and aircraft 

operations research, 89- 103; and aircraft systems 

research, 75-87; and Airport 85 research, 114-16; 

and Roeing 737 research systems, 14-18; and 

cockpit computerization, 36-39; and cockpit 

displayed traffic information research, 93-94; and 

computerization and electronic flight displays 

research, 25-39; and data link research, 95-99; 

and digital access communication research, 75, 

76-78; and electronic flight display research, 

27-33; and engine monitoring and control 

system, 75, 83-85, 120; and global positioning 

system research, 50-53, 102, 120, 122; and 

helmet mounted display research, 112-14; and 

high lift research, 108-109; and instrument 

landing systeni signal modelling research, 

1 16- 17; and microburst windshear research, 

55-73; and large eddy break-up research, 

108-1 09; and magnetic cable guidance research, 

101-102; and microwave landing system, 11, 15, 

21, 27, 34, 41 -53, 120, I2 1 ; optical propulsion 

management interface, 78-80; and precision flare 

laws research, 99-101; and profile descent 

research, 90-9.3; program organization, 18-23; 

and runway friction research, 109- 12; and takeoff 

performance monitoring system, 75, 76, 85-87; 

;ind technology transfer, 1-7, 33-36; and total 

energy control system, 75, 81 -83, 120; and wing 

surface coatings research, 106- I07 

Texas Instruments: 43 

Toshiba Corp.: 35 

Airborne Trailbhzer 
Total Energy Control System: 75, 81-83, 120 

Traffic Alert Collision Avoidance System: 94 

Transportation, Department of: 9, 13, 14,42, 43,47 

Trippe, Juan: 33 

United Nations: 42 

United Technologies, Inc.: 80 

Wallops Island, VA 43, 52, 86, 93, 97, 101, 110, 113-14 

Wallops Flight Facility: 43, 52, 66, 86, 93, 97, 101, 110, 

Warner, John: 33 

Washington, DC: 10,84, 109 

Washington National Airport: 109 

Westinghouse Electric Co.: 72 

Windshear, Microburst: 55-73 

Windshear Training Aid: 60-62 

Wing Surface Coatings: 106-107 

Withington, H.W.: 6, 38-39 

World Airways: 109 

113-14 

Yenni, Kenneth R. "Dick": 68 

About the Author 

ane E. Wallace is a professional aviation L writer who lives in Minneapolis, 

Minnesota. She has published over 200 articles 

on a wide variety of aviation and aerospace 

topics ranging from biplanes and air racing to 

new developments in NASA research and 

military aircrafi technology. Her writing has 

appeared in a number of national and 

international magazines, including AOPA Pilot, 

Flight International, JP-4 Aeronautica, Flyer, and 

Panorama Difesa. In addition, her work has 

earned her an honorary membership in the 

United States Air Force Society of Wild Weasels, 

as well as a citation for “Outstanding 

Contributions to Preserve General Aviation” by 

the Torrance, California Airport Association. 

Ms. Wallace graduated with honors from 

Brown University in 1983, with a degree in 

Semiotics. She owns and flies her own airplane, a 

1946 Cessna 120, and is currently working with 

a partner on a 1943 Boeing Stearman restoration 

project. In addition to her own airplane projects, 

she has also worked as a volunteer for the Planes 

of Fame Air Museum in Chino, California, and 

both the “Tsunami” and “Pond Racer” 

Unlimited air racing crews. 
186 

Hook design and production by 

Steve Chambers and Lynn Van der Veer 

Creative Services, Washington, D.C. 

Type composed in Adobe Garamond 

Printed on recycled paper 

Airborne Trailblawr 
The NASA History Series 

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Airborne Trtrilblazr