SP-4220 Wingless Flight: The Lifting Body Story

 

INTRODUCTION

 

[vii] Wingless Flight tells the story of the most unusual flying machines ever flown, the lifting bodies. It is my story about my friends and colleagues who committed a significant part of their lives in the 1960s and 1970s to prove that the concept was a viable one for use in spacecraft of the future. This story, filled with drama and adventure, is about the twelve-year period from 1963 to 1975 in which eight different lifting-body configurations flew. It is appropriate for me to write the story, since I was the engineer who first presented the idea of flight-testing the concept to others at the NASA Flight Research Center. Over those twelve years, I experienced the story as it unfolded day by day at that remote NASA facility northeast of Los Angeles in the bleak Mojave Desert.

Benefits from this effort immediately influenced the design and operational concepts of the winged NASA Shuttle Orbiter. However, the full benefits would not be realized until the 1990s when new spacecraft such as the X-33 and X-38 would fully employ the lifting-body concept.

A lifting body is basically a wingless vehicle that flies due to the lift generated by the shape of its fuselage. Although both a lifting reentry vehicle and a ballistic capsule had been considered as options during the early stages of NASA's space program, NASA initially opted to go with the capsule. A number of individuals were not content to close the book on the lifting-body concept. Researchers including Alfred Eggers at the NASA Ames Research Center conducted early wind-tunnel experiments, finding that half of a rounded nose-cone shape that was flat on top and rounded on the bottom could generate a lift-to-drag ratio of about 1.5 to 1. Eggers' preliminary design sketch later resembled the basic M2 lifting-body design. At the NASA Langley Research Center, other researchers toyed with their own lifting-body shapes.

Meanwhile, some of us aircraft-oriented researchers at the NASA Flight Research Center at Edwards Air Force Base (AFB) in California were experiencing our own fascination with the lifting-body concept. A model-aircraft builder and private pilot on my own time, I found the lifting-body idea intriguing. I built a model based on Eggers' design, tested it repeatedly, made modifications in its control and balance characteristics along the way, then eventually presented the concept to others at the Center, using a film of its flights that my wife and I had made with our 8-mm home camera. I recruited the help of fellow engineer Dick Eldredge and research pilot Milt Thompson, especially in later selling the idea to others, including Paul Bikle, then the director of the NASA Flight Research Center (redesignated in 1976 the Hugh L. Dryden Flight Research Center). What followed was history, and telling for the first time in print that historic story of the lifting bodies in full and living detail is what this book is all about.

 


[
viii]

Dale Reed holding the original free-flight model of the M2-F1 filmed in 8mm movies used to convince Dryden and Ames managers to support the program. The full-scale M2-F1 dlown later is in the background.

Dale Reed holding the original free-flight model of the M2-F1 filmed in 8 mm movies used to convince Dryden and Ames managers to support the program. The full-scale M2-F1 flown later is in the background. (NASA photo EC67 16475).


 

[ix] Between 1963 and 1975, eight lifting-body configurations were flown at the NASA Flight Research Center at Edwards AFB. They varied tremendously from the unpowered, bulbous, lightweight plywood M2-F1 to the rocket-powered, extra-sleek, all-metal supersonic X-24B. Some configurations, such as the M2-F2, not only pushed the limits of both design engineers and test pilots but also were dangerous to fly. Film footage of the 1967 crash of the M2-F2, after test pilot Bruce Peterson lost control of this particularly "angry machine," was used about two years later as the lead-in to weekly episodes of a popular television series, The Six-Million-Dollar Man, which ran for about six years. Although the M2-F2 crash was spectacular enough to inspire the concept for a popular television series, it was the only serious accident that occurred over the slightly more than twelve years of lifting-body flight-testing.

But danger has always lurked at the edge of flight innovation. All eight of these wingless wonders, the lifting bodies, were considered the flying prototypes for future spacecraft that could land like an airplane after the searing heat of reentry from outer space. The precursors of today's Shuttle and tomorrow's X-33 and X-38, the lifting bodies provided the technical and operational engineering data that has shaped the space transportation systems of today and tomorrow.

 

The Place and the People

 

The story of the lifting bodies is not just a story about wingless machines that fly. It is a story as much about people and the unique environment of the NASA facility at Edwards AFB as it is about airplanes. The driving force behind the lifting-body program was the small contingent of people at the NASA Flight Research Center at Edwards AFB in the western Mojave Desert northeast of Los Angeles.

Brought together originally in 1946 to flight-test the Bell XS-1, the little group of strong-minded individuals was also drawn to this remote facility because of their love for airplanes and the adventure of flight-testing. Being surrounded by aviation history in the making was enough to keep motivation flying high.

The NASA facility at Edwards-called initially the National Advisory Committee for Aeronautics (NACA) Muroc Flight Test Unit-was paradise to these lovers of airplanes. It was a place where people got their hands dirty working on aircraft, a place where they had the freedom to kick an airplane tire at any time. It was a place where test pilots, engineers, mechanics, and technicians all breathed the same air and walked the same halls, shops, and hangar floors. It was a place where they could take a few minutes off from tightening a bolt on an aircraft to watch a new airplane design making a flyover. The boss probably was also an airplane lover, and more than likely, he too had stopped whatever he was doing to watch the same flyover. And it was a [x] place where about the most exciting thing in life was being involved as a volunteer in a new program.

In 1963, the lifting-body program began, circumventing the normal bureaucratic process by launching itself as a bottom-up program. It began when an enthusiastic engineer drew together a band of engineers, technicians, and pilots-all volunteers, of course-and then moved ahead, bypassing the ponderous amount of paperwork and delays of months or even years typically involved in officially initiating approved and funded aerospace programs in that era.

Besides tapping into the volunteer spirit present in the 1960s at the NASA Flight Research Center, the unofficial lifting-body program also used creative methods to locate funds. Shortly before his death in January 1991, Paul Bikle explained how that was done, saying "it was a real shoestring operation. We didn't get any money from anybody. We just built it out of money we were supposed to use to maintain the facility."1 As the program grew over the years to involve flight-testing eight different configurations, it became more disciplined and organized. Even then, however, it was still individuals-not organizations-that made things happen.

The lifting-body concept was a radical departure from the aerodynamics of conventional winged aircraft, and it was the operational experience of the NASA and Air Force people at Edwards AFB that made the program a reality. Setting the stage for the lifting-body program was the long experience of these engineers, technicians, and pilots over previous decades in flight-testing experimental, air-launched, and rocket-boosted gliders from the XS-1 to the X-15.

A special kind of camaraderie existed among the otherwise competitive NASA and Air Force people and aircraft contractors who worked in the shops and labs of this relatively isolated facility. Often, for example, a mechanic who needed a special tool or piece of equipment would go next door on the flight line to a competing contractor and borrow what was needed. Flight-testing was difficult, demanding, and time-critical work. By helping each other get through critical times, everyone benefited from the unofficial cooperation that was a hallmark of the facility even then.

An anti-waste mentality was another hallmark of Edwards at the time. If an old piece of equipment could do the job as well as a new piece of equipment, why spend the money and time developing the new piece of equipment when the program could be moved along speedily by refurbishing and using the old one? One of the best examples of this recycling was the extensive use made of Thiokol's Reaction Motors [xi] Division LR-11 (later designated the XLR-11), a rocket engine flown in rocket-powered experimental aircraft at Edwards for nearly 30 years, from 1947 to 1975.

The most famous use of this engine was to propel Chuck Yeager and the Bell XS-1 in the world's first supersonic flight in 1947. The Army-version LR-11 was also used to propel later models of the Bell X-1. A virtually identical Navy version called the LR-8 was used through 1959 on Douglas D-558-II rocket-powered aircraft. To keep the X-15 program on schedule, despite delays while the Thiokol XLR-99 rocket engine was being developed, a pair of old LR-11s was used in the X-15 until the bigger engine became available. During the year that followed until the XLR-99 was available, the X-15 was flown with the LR-11s and achieved speeds up to Mach 3.23. Later, many of the old LR-11 engines were donated to various aeronautical museums, some installed in the old X-1 or D-558-II aircraft and some shown as separate engine displays.

Six years afterwards, these engines were removed from the museums, refurbished, and recycled into flight-testing in the lifting-body program. Of the eight lifting-body configurations developed, four of them were powered by LR-11 rocket engines "borrowed" from museums. The last flight-test of a lifting body using an LR-11 engine occurred on 23 September 1975. Afterwards, the LR-11s found their way back to the museums, now installed in lifting bodies as well as other historic rocket-powered research aircraft.

The extremely low-cost M2-F1 launched the unofficial lifting-body program in 1963. Dubbed the "Flying Bathtub," this simple little vehicle was towed aloft by either a car or an old R4D, the Navy version of the C-47 aircraft. Except for the Hyper III, which was flown by remote control, the lifting-body vehicles were flown with research pilots on board. Two of the configurations, the M2-F2 and the first glider version of the HL-10, were marginal to control and later were modified aerodynamically to produce good flying aircraft. The original flight versions, which I call the "angry machines," tested the limits of research pilots' capabilities. We were very fortunate at the time to have a pool of the world's best research pilots to fly these marginally controllable aircraft until we, as engineers, got smart enough to convert them into good flying machines. Another lifting body, the Air Force X-24A, was converted into the X-24B, a totally new form of lifting body that I call a "racehorse" because it led toward high hypersonic aerodynamic performance.

Begun while the X-15 was still being flight-tested, the lifting-body program was unique when compared with previous research, in which most aircraft design activities were conducted by contractors and delivered to the government to meet performance specifications. For instance, the basic X-15 design, except for minor but important changes, was tested by expanding the flight envelope to the maximum speed and altitude capabilities of the aircraft. In this way, the X-15 program was mainly ....

 


[
xii]

Drawing showing the evolution of lifting-body flight vehicles starting with the M2-F1 flown in 1963-1966; <<angry machines>> M2-F2 and the original HL-10 flown in 1966-67; mature <<plow-horse>> lifting bodies M2-F3, HL-10 modified, and X-24A flow in 1968-73; and finally, the <<race horse>> lifting bodies Hyper III and X-24B flown in 1970-75 (original drawing by Dale Reed, digital version by Dryden Graphics Office.)

Drawing showing the evolution of lifting-body flight vehicles starting with the M2-F1 flown in 1963-1966; "angry machines" M2-F2 and the original HL-10 flown in 1966-67; mature "plow-horse" lifting bodies M2-F3, HL-10 modified, and X-24A flow in 1968-73; and finally, the "race horse" lifting bodies Hyper III and X-24B flown in 1970-75 (original drawing by Dale Reed, digital version by Dryden Graphics Office.) [Click here for a larger image]


 

....driven by operational and hardware considerations, whereas the lifting body was mainly a design engineers program with NASA and Air Force engineers doing the basic aerodynamics and control-system designs, wind-tunnel testing, and simulation and control system analysis.

All of the NASA lifting-body configurations-the M2-F1, M2-F2, M2-F3, Hyper III, HL-10, and modified HL-10-were developed within NASA facilities. The aerodynamic shapes were developed in NASA wind tunnels, and the control-system control laws were developed at the Flight Research Center by NASA engineers and research pilots using simulators and other analytical techniques. Northrop, the contractor, then designed and built the hardware to meet these specifications, relying ...

 


[
xiii]

Paul Bikle - Director of the NASA Flight Research Center from  1959-1971 who provided strong support for the lifting-body program.

Paul Bikle - Director of the NASA Flight Research Center from 1959-1971 who provided strong support for the lifting-body program. (NASA photo E68 19647).


 

...totally on the work done by the NASA and Air Force engineers. I believe that this was an unprecedented arrangement between government and contractor technical people, everyone working together as one design team.

 

[xiv] Paul Bikle

 

From what I've described so far, someone might form the impression that the NASA Flight Research Center in the 1960s was an organization of undisciplined do-as-you-like individuals. Just the opposite was true. Paul Bikle, the director of the NASA Flight Research Center at that time, was a strong disciplinarian who came to NASA from a military background. A lover of air-planes, he started his career designing light planes for Taylor Aircraft Company before World War II. He was a civilian flight-test engineer at Wright-Patterson Air Force Base, testing B-17s, B-24s, B-25s, B-29s, P-51s and other Air Force aircraft of the time. Next, he became the civilian director for flight-testing military jet aircraft with the Air Force at Edwards AFB, working closely with many top Air Force pilots, including Jimmy Doolittle and Chuck Yeager.

After his career with the Air Force, Bikle was recruited to head up the NASA Flight Research Center at Edwards, which had just been assigned to develop a flight-test program for the X-15. His ability to lead a highly disciplined flight-research organization dedicated to achieving timely results had been demonstrated many times in his Air Force career, making him an ideal choice for this job. Walt Williams-the original director of the NASA Flight Research Center-went on to lead the Mercury and Gemini space programs at Johnson Space Center.

From 1959 to 1969, Paul Bikle organized and conducted the three-aircraft, hypersonic, rocket-powered X-15 program in a highly professional and disciplined manner. Even though the X-15 program was the major activity at the NASA Flight Research Center at the time, Bikle saw the NASA facility as a research center that had to stay tuned to the aerospace world, prepared to move ahead when opportunity arose. As a result, about half of the staff was committed to X-15 research, the other half available to conduct other aeronautical research geared to the future.

Having worked closely with test pilots for years and being an accomplished pilot himself (having set the world's altitude record for sailplanes), Bikle had the uncanny ability to gauge accurately the abilities of research pilots. He also knew the abilities of most of the roughly 400 individuals then at the NASA Flight Research Center. Almost daily, Bikle wandered through the shops, talking to mechanics and engineers in their offices. Besides touring the hangars, shops, and offices, he usually played cards during lunch in the radio shop. In these ways, he stayed in touch with the pulse of the place and the people. He knew more about the daily details of the Center than did most of the engineers and project managers. He also had his own style of asking questions. He already knew the answers to the questions he was asking, but had found that asking questions was a good way of gauging how much the person knew about what was going on.

[xv] A small and balding man, Paul Bikle commanded so much respect and authority that when you met him in the hallway, he seemed ten feet tall. Years later, after he retired, he added radio-controlled model flying to his first love, soaring. One day, while he and I were flying radio-controlled gliders at the beach, I had the crazy idea that, if I had to, I could lick this friendly little guy in a fist fight. It was a crazy idea because never before had I thought of him as anything but a giant you didn't cross unless you were stupid.

Bikle disliked using up people's time with unnecessary meetings. He held one weekly meeting to take care of any and all unresolved problems. Usually, he was so attuned to daily details within the Center that he knew about a problem before it was voiced at a meeting. The meeting soon became known as the "Bikle Barrel," instilling terror in the hearts of any supervisor or project manager who had screwed up that week. Not believing that any good could come from reprimands or punishments, Bikle found that exposing screw-ups in the weekly meetings was sufficient to keep all of his people on their toes afterwards. No one was immune to the Bikle Barrel, and I had my turn a few times, too.

Bikle occasionally used other unorthodox methods to motivate people. For example, he bet several of the lifting-body people that the M2-F2 would not fly before 1 July 1966. On 8 June, the XB-70 crashed, intensifying the normal safety-of-flight worries. Even minor problems in the lifting-body program began to loom large in the aftermath of the XB-70 accident. In the next weekly meeting, Bikle decided that the entire lifting-body project would stand down for 30 days, with no attempts made to fly until all problems had been fully evaluated. At the end of the meeting, a pile of money began accumulating in front of Bikle as those with whom he had bet paid off. He simply smiled, picked up the money, and left the room. The moral: Never bet against someone who controls the game.

His more personable side came out in informal one-on-one sessions. Like most of us at the Center in those days, Bikle was in love with airplanes and loved to swap flying stories or talk about new airplane designs. Many of the big names in aviation were his personal friends. I can remember finagling my way into sitting at the same NASA cafeteria table with Paul Bikle and Chuck Yeager, just to be able to listen to them swap flying stories. In those days, I felt like a child listening to the bigger boys talk, often having to work to keep my eyes from bugging out and my mouth from dropping open in pure amazement.

Bikle was also very knowledgeable about flight-test and research techniques, even doing a professional-level flight program of his own on weekends of many of the state-of-the-art sailplanes of the time. He published their gliding performance results [xvi] in reports still used today by designers of subsonic aircraft requiring very high lift-to-drag ratios.

Innovation is a personality characteristic, Bikle believed, not something that can be taught in schools or training programs. He knew that this characteristic might lie within any technician in the shop or any engineer in the office. While wandering through shops and offices, talking to various individuals, he was able to calibrate many personalities and get a feeling for individual skill levels. The door to his office was always open to anyone who had an idea that he or she wanted to share with him.

 

The Lifting-Body Pilots

 

Paul Bikle emphasized teamwork, making it clear that each engineer and technician was just as important as each research pilot to the success of the flight project. In actuality, however, the work team didn't always see it this way. The research pilots were often thought to be like the Greek gods on Mount Olympus. After all, the success or failure of a project-after long weeks, months, or years of the team's hard work-depended on one pilot doing the job right for the few minutes of that first critical flight.

Many of us involved in the project were also private or amateur pilots imbued with tremendous admiration for our fellow team members, the research pilots. Many of us envied these pilots, often trying to mentally put ourselves into their minds and bodies during flight tests. In the early days, before flights were conducted from control rooms, the radio was the primary contact point between the pilots and others on the ground. If a pilot chose to say nothing during a flight, we fairly much had to wait for the post-flight debriefing to hear how things had gone during the flight. However, we did have on-board aircraft data recordings that we could process to verify the accuracy of pilot reports.

Later, when we developed a control room at the Center for the X-15 project, research and flight-test engineers could participate in the flight by watching data displayed on consoles in various forms-dials, wiggly lines on paper rolls, and pens moving across radar maps to show the position of the aircraft. Sometimes we could influence the course of the flight by sending a message to the pilot over the radio through a control-room communicator, usually another research pilot. The ground-based communicator, who had the only radio mike in the control room, could filter comments by engineers, deciding whether they were important enough to communicate to the airborne research pilot.

As engineers, we began to feel that we were a part of the flight once we were able to see real-time data coming into the control room by way of telemetered radio signals. [xvii] Nevertheless, the spotlight remained on the research pilot. He was the man of the hour, all eyes watching to see that he did his job properly. All of the lifting-body pilots, with the exception of Chuck Yeager, had college degrees in engineering or physics. These "tigers of the air" do not fit any one stereotype, the spread of personality types ranging from the "intellectual," as represented by Fred Haise and Einar Enevoldson, to the talented "stick-and-rudder men," represented by Chuck Yeager and Joe Engle.

The flight performance of any pilot on any given day depended not only on his experience and skills but also on a number of personal factors, including whether he had had a disagreement the night before with his wife. All but one of the lifting-body pilots were current or former military fighter pilots, and fighter pilots by nature seemed to need sizable egos to be good at what they do. The spotlight appealed differently to each pilot's ego, with varying results.

For example, some of the lifting-body configurations had very poor flying characteristics, which created situations in which pilots could cause oscillations by over-controlling. This condition is called "pilot-induced oscillation" (PIO), a deviation from controlled flight that can happen with the best of pilots if the flying characteristics of the aircraft are bad enough. However, the pilots with the biggest egos often had the most difficulty admitting they were involved in a PIO situation during a flight.

The lifting-body pilots also seemed to belong to an unofficial but exclusive club in the pilots' office. The performance of any pilot could be judged only by his fellow pilots or by his boss, Paul Bikle for the NASA pilots and various Air Force commanders for the Air Force pilots. It was not considered proper for flight-test or research engineers to suggest that a pilot's performance was not up to par. The lifting-body pilots included many top test pilots. Consequently, problems in flying the lifting-body vehicles were often thought to be the fault of the engineers who had created configurations that were marginally controllable, rarely if ever considered to result from any lack of piloting skill.

Chuck Yeager had his own pilot rating system, the pilot bosses had theirs, and we research engineers had our own. As research engineers, we unofficially divided the pilots into two categories: those who were research test pilots, who would try hard to bring home quality data, and those who were just test pilots, who could expand envelopes and bring the aircraft home safely but who were sloppy with regards to data. We were fortunate that most of the lifting-body pilots were also true research test pilots and that we got the data we wanted.

The era of the lifting bodies began with a very modest program involving only one pilot, Milt Thompson. The program grew over the years to include 8 different lifting-body configurations flown by 17 pilots, 8 of whom were NASA, the others Air Force. Sixteen of the seventeen pilots had fighter aircraft backgrounds and one, Dick Scobee, had large airplane experience.

 


[
xviii]

Pilot

Number of flights

M2-F1

M2-F2

HL-10

HL-10 modified

M2-F3

X-24A

Hyper III

X-24B

Total

.

1. Milt Thompson

45

5

.

.

.

.

1

.

51

2. Bruce Peterson

17

3

1

.

.

.

.

.

21

3. Chuck Yeager

5

.

.

.

.

.

.

.

5

4. Don Mallick

2

.

.

.

.

.

.

.

2

5. James Wood

Car T.

.

.

.

.

.

.

.

.

6. Don Sorlie

5

3

.

.

.

.

.

.

8

7. Bill Dana

1

.

.

9

19

.

.

2

31

8. Jerry Gentry

2

5

.

9

1

13

.

.

30

9. Fred Haise

Car T.

.

.

.

.

.

.

.

.

10. Joe Engle

Car T.

.

.

.

.

.

.

.

.

11. John Manke

.

.

.

10

4

12

.

16

42

12. Pete Hoag

.

.

.

8

.

.

.

.

8

13. Cecil Powell

.

.

.

.

3

3

.

.

6

14. Mike Love

.

.

.

.

.

.

.

12

12

15. Einar Enevoldson

.

.

.

.

.

.

.

2

2

16. Francis Scobee

.

.

.

.

.

.

.

2

2

17. Tom McMurtry

.

.

.

.

.

.

.

2

2

.

Total

77

16

1

36

27

28

1

36

222

Lifting-body pilot list showing number of flights per lifting body by each of the 17 lifting-body pilots (compiled by Betty Love).


 

All of the pilots had other test or research responsibilities on other aircraft programs within NASA and the Air Force, the typical lifting-body flights being weeks or even months apart. Often, these other programs involved research or developmental military aircraft being tested at Edwards at the same time we were flying the lifting bodies. We were fortunate in the lifting-body program to be able to tap into this elite source of pilots when we needed them.

We were even able to get Chuck Yeager to take time from his busy schedule during the first year of the lifting-body program to fly the M2-F1 and give his assessment of this vehicle. Three of the lifting-body pilots went on to be astronauts. Fred Haise went to the Apollo program and flew the Shuttle landing approach tests. Joe Engle and Dick Scobee became Shuttle commanders for space flights.

A total of 222 lifting-body flights were made in those twelve busy years. Topping the list was the M2-F1 with 77 air tow flights. The HL-10 Modified and the X-24B had 36 flights each. The X-24A flew 28 times; the M2-F2 had 16 flights; the M2-F3, 27; and the original HL-10 and Hyper III had only one flight each.

Here is a thumbnail introduction to the pilots, given in the order in which they first flew vehicles in the lifting-body program:

Milton O. Thompson, the first lifting-body pilot, flew the M2-F1 on its first flight on 16 August 1963. Milt flew the M2-F1 16 more times before the next two pilots, ....


[
xix]

Milt Thompson - first lifting-body pilot- standing beside the M2-F1 configuration selected for flight (without a center fin).

Milt Thompson - first lifting-body pilot- standing beside the M2-F1 configuration selected for flight (without a center fin). (NASA photo EC63 206)



A happy Bruce Peterson - second lifting-body pilot - after he successfully piloted the marginally controllable HL-10 on its first flight.

A happy Bruce Peterson - second lifting-body pilot - after he successfully piloted the marginally controllable HL-10 on its first flight. (NASA photo E66 16199-1)


 

....Bruce Peterson and Chuck Yeager, were invited to fly it. In all, Milt flew the M2-F1 45 times. He also made the first five flights of the heavy-weight M2-F2 lifting body, a grand total of 51 lifting-body flights. All of his flights were glide flights.

Milt was instrumental in the start-up of the lifting-body program. It would have been difficult to sell the lifting-body program to project managers without the help of Milt's charm. After flying the M2-F2, Milt retired as a flight research pilot, then moved into setting up training programs and working with Paul Bikle in evaluating new pilots for the later lifting-body projects.

Bruce A. Peterson, the second lifting-body pilot, made a total of 21 flights on three different lifting bodies: the M2-F1 17 times, the M2-F2 3 times, and the HL-10 once. On 22 December 1966, he became the first pilot to fly the HL-10. He retired from test flying following the crash of the M2-F2 on 10 May 1967.

Chuck Yeager was the third pilot to fly a lifting body, making five flights of the M2-F1, one on 3 December 1963, and two each on 29 and 30 January 1964. Paul Bikle wanted his old friend and master test-pilot, Colonel (later General) Chuck Yeager, to fly the M2-F1 early enough to give an assessment before other Air Force pilots flew the vehicle. At the time, Yeager headed up the USAF Aerospace Research Pilot School, also known as the Test Pilot School, at Edwards. Bikle thought that Yeager gave the most accurate and descriptive flight test report of any pilot that Bikle had ever worked with in the Air Force or NASA. Although Yeager never flew any of the rocket-powered lifting bodies, he exerted consider-able influence, encouraging the Air Force in developing the rocket-powered X-24A and X-24B as well as in the conceptualization of the jet-powered X-24J, which was never built.

Yeager could be very blunt and straightforward when it came to evaluating the performances of other test pilots, and perhaps those who received the brunt of his criticism might not hold him in as high a regard as I and others do. Yeager basically divided test pilots into two categories: those who can hack it, and those who cannot. He minced no words in his verbal or written criticism of those pilots who made more than a limited number of mistakes in the stick-and-rudder department. Nor did he mince words in evaluating how well an aircraft handled or performed.

The fourth lifting-body pilot, Donald L. Mallick made only one lifting-body flight with the lightweight M2-F1 on 30 January 1964. James W. Wood, the fifth lifting-body pilot, made only car tows on 6 February 1964. Maj. Wood was transferred by the Air Force to another command and did not get a chance to fly the M2-F1 in air tow. He had been one of the original X-20 (Dyna-Soar) pilots selected by the Air Force.

Donald M. Sorlie, the sixth lifting-body pilot, made his first air-towed flight in a lifting body on 27 May 1965. The official Air Force "boss" of the lifting-body and X-15 Air Force test pilots, Lieutenant Colonel Sorlie made five flights in the M2-F1 and three in the M2-F2, just enough to evaluate what kind of challenge would....

 


[
xxi]

Bill Dana, seventh lifting-body pilot, who flew 4 lifting-body configuration including 19 flights on the M2-F3 for a total of 31 lifting-body flights. The HL-10 is shown behind him.

Bill Dana, seventh lifting-body pilot, who flew 4 lifting-body configuration including 19 flights on the M2-F3 for a total of 31 lifting-body flights. The HL-10 is shown behind him. (NASA photo E69 20288).



Then-Capt. Jerauld Gentry, principal Air Force and eighth lifting-body pilot overall, who flew 5 lifting-body configurations including 13 on the X-24A for a  total of 30 lifting-body flights.

Then-Capt. Jerauld Gentry, principal Air Force and eighth lifting-body pilot overall, who flew 5 lifting-body configurations including 13 on the X-24A for a total of 30 lifting-body flights. (NASA photo, EC97 44183-1)


 

[xxii] ...confront his test pilots in these lifting bodies. At the time, he was Chief of the Fighter Operations Branch, Flight Test Operations-the primary pool of Air Force test pilots at Edwards AFB.

The seventh pilot to fly a lifting body, William H. Dana, had 31 lifting-body flights over a little more than ten years, flying the lifting-bodies over a longer span of time than did any other pilot. He had his first lifting-body flight in the M2-F1 on 16 July 1965. He also flew the HL-10 and the M2-F3. His last lifting-body flight was in the X-24B on 23 September 1975.

Dana received the NASA Exceptional Service Medal for his ten years as a research pilot in four of the lifting-body vehicles (M2-F1, HL-10 modified, M2-F3, and X-24B). In honor of his research work on the M2-F3 lifting-body control systems, Dana in 1976 received the American Institute of Aeronautics and Astronautics' Haley Space Flight Award.

Jerauld R. Gentry, the eighth lifting-body pilot, was the chief Air Force lifting-body pilot, making a total of 30 lifting-body flights. Major Gentry made his first air-towed flight on the M2-F1 on 16 July 1965. He also flew the M2-F2, the HL-10, and the X-24A. He made his last lifting-body flight in the M2-F3 on 9 February 1971. Major Gentry developed a reputation as an outstanding lifting-body research pilot, flying the X-24A on its first glide flight as well as its first rocket-powered flight, demonstrating a high level of skill in gathering the flight data needed by engineers in expanding the X-24A's flight envelope.

The ninth and tenth lifting-body pilots, Fred Haise and Joe H. Engle, flew the M2-F1 on car tows up to altitudes of 25 and 30 feet on 22 April 1966. Neither of them flew the M2-F1 from airplane tows, nor did they fly any of the B-52 launched lifting bodies.

Soon after flying the M2-F1 in 1966, Haise was assigned as an astronaut at Johnson Space Center, precluding any additional involvement with the lifting-body project. Later, Haise was on the ill-fated Apollo 13 flight, which almost ended in disaster following an explosion in space, the topic of the popular movie Apollo 13 that premiered in 1995. General Joe Engle also had his assignment to the lifting-body project cut short when he was one of 19 astronauts selected in March 1966 for NASA space missions. I would have liked to have seen how well Joe Engle, in particular, would have performed over time as a lifting-body pilot. He shared many of Chuck Yeager's characteristics: he, too, was full of 'piss and vinegar' as well as one of the best stick-and-rudder men around.

John A. Manke, the eleventh lifting-body pilot, was the second busiest with 42 lifting-body flights, the busiest being Milt Thompson with 51. Most of Manke's flights were rocket-powered, while all of Thompson's were glide flights, including the remotely piloted Hyper III in which Milt "flew" from a ground cockpit. Manke's first flight...

 


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John Manke, eleventh lifting-body pilot, who flew 4 different configurations including 16 X-24B flights for a total of 42 lifting-body flights.

John Manke, eleventh lifting-body pilot, who flew 4 different configurations including 16 X-24B flights for a total of 42 lifting-body flights. (NASA photo EC69 2247)


 


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Lt.Col. Michael Love, fourteenth lifting-body pilot, who flew the X-24B 12 times.

Lt.Col. Michael Love, fourteenth lifting-body pilot, who flew the X-24B 12 times. (NASA photo E75 29374)


 

....was a glide flight on the modified HL-10 on 28 May 1968. Manke flew the HL-10 ten times, the M2-F3 four times, the X-24A twelve times, and the X-24B sixteen times. He made his last flight on 5 August 1975 in the X-24B.

The twelfth pilot to fly a lifting body, Peter C. Hoag, first flew the modified HL-10 on 6 June 1969. Major Hoag made his eighth flight on the HL-10 on 17 July 1970. This was also the last flight of the HL-10. While flying the HL-10 on 18 February 1970, Major Hoag set the speed record for all of the lifting bodies-Mach 1.86.

. Cecil William Powell, the thirteenth lifting-body pilot, had his first lifting-body flight on 4 February 1971, a glide flight in the X-24A. He flew the X-24A and the M2-F3 three times each. His last flight on a lifting-body was a rocket flight on the M2-F3 on 6 December 1972.

Fourteenth among the pilots to fly a lifting body, Michael V. Love first flew the X-24B on 4 October 1973. A year later, on 25 October 1974, Lieutenant Colonel Love set the speed record of Mach 1.76 for the X-24B. On 15 July 1975, he had his twelfth and final flight of the X-24B.

Einar Enevoldson, the fifteenth lifting-body pilot, made his first of two glide flights in the X-24B on 9 October 1975. He was one of three guest pilots invited to fly the X-24B in glide flights as part of a guest-pilot evaluation test exercise at the end of the [xxv] X-24B flight program after the official research flights had been completed. Each of the three guest pilots (including Major Francis R. "Dick" Scobee and Thomas C. McMurtry) flew the X-24B twice.

Francis R. "Dick" Scobee, the sixteenth lifting-body pilot, first flew the X-24B on 21 October 1975. Primarily an Air Force transport test pilot, Major Scobee was the only lifting-body pilot with no background as a fighter pilot. He kidded us, saying he was selected as a guest pilot to prove that if a transport pilot could fly the X-24B, then any pilot could fly future spacecraft versions of the X-24B.

The X-24B shared very similar speed and performance characteristics with the projected Shuttle spacecraft design, so the X-24B was used to collect operational data used in the design and development of the Space Shuttle vehicles. Scobee said that his experience flying the X-24B inspired him to apply to the NASA Astronaut Corps to fly the Shuttle spacecraft. He was selected as an astronaut for NASA in January 1978. On 28 January 1986, Scobee unfortunately perished in the Challenger explosion.

Thomas C. McMurtry was the seventeenth and final pilot to fly a lifting body, doing so as the third invited guest pilot at the end of the X-24B program. He flew the X-24B in glide flight twice, once each on 3 and 26 November 1975. 2

 

How Wingless Flight Came to be Written

 

My life-long love affair with airplanes has kept me from truly retiring. After I retired from NASA in 1985, I was recruited to manage the development at Lockheed of various Remotely Piloted Vehicles (RPVs), working four years at the Lockheed Advanced Development Plant known as the "Skunk Works," managing design, vehicle development, and flight-test programs.

After I left Lockheed in 1989, still unable to pull myself away from an active involvement with aircraft, I served as a consultant to various aircraft organizations and soon found myself working as a contractor, supporting NASA programs at NASA Dryden, Edwards AFB. Once more I was able to work with some of my old NASA friends at Dryden, including Milt Thompson.

Milt had been working on a book entitled At the Edge of Space,3 which told the story of the X-15. After this book was published in 1992 by the Smithsonian Institution Press, Milt was asked if he would write a book telling the lifting-body story. For several years, I had thought of writing just such a book. However, at the time, I [xxvi] was too busy having fun coming up with new ideas for creating new airplane programs. With the new miniature computers and global-positioning satellite systems, I was totally involved with developing autonomously-controlled unpiloted air vehicles of all sorts.

Milt Thompson died suddenly on 6 August 1993. Before his death, Milt had begun writing the book that would tell the lifting-body story, but he had not finished it at the time of his death, leaving me as the only remaining lifting-body team member who knew the full lifting-body story from beginning to end. If a book telling the entire story were to be written, it seemed that I was the only one left who could do it.

By this time, the professional aerospace writer and historian Richard P. Hallion had already published three excellent histories telling aspects of the story. First published by the Smithsonian in 1981, Test Pilots4 tells the complete story of flight-testing, from the earliest tower jumps in 1008 to the around-the-world flight of the Voyager in 1986. On the Frontier,5 published in 1984 as a volume in the NASA History Series, is a comprehensive history of flight research at NASA Dryden after World War II, 1946-1981. The Hypersonic Revolution,6 published in 1987 by the U.S. Air Force, is mammoth in scope, covering events from 1924 to 1986-from the early rocket experiments to the aerospace plane.

Richard Hallion has already done an excellent job in these books in documenting the historic facts as well as the political and managerial aspects of the lifting-body story. What remains untold is the story that facts alone cannot tell: the human drama as it unfolded in the day-by-day activities of the people who lived and breathed the lifting-body adventure from 1963 to 1975.

Wingless Flight tells that story, for I remain convinced that it is about more than machines; it is at least as much about the people with the "real stuff," who created and maintained the machines, as it is about the individuals with the "right stuff," the pilots who flew the lifting bodies.


Notes

 

1 Quoted in Stephan Wilkinson, "The Legacy of the Lifting Body," Air & Space (April/May 1991), p. 54.

2 Thanks to Betty Love for checking and correcting the statistics for this section.

3 Milton O. Thompson, At the Edge of Space: The X-15 Flight Program (Washington, D.C.: Smithsonian Institution Press, 1992).

4 Richard P. Hallion, Test Pilots: The Frontiersmen of Flight (Washington, D.C.: Smithsonian Institution Press, 1981).

5 Richard P. Hallion, On the Frontier: Flight Research at Dryden, 1946-1981 (Washington, D.C.: NASA SP-4303, 1984).

6 Richard P. Hallion, The Hypersonic Revolution: Eight Case Studies in the History of Hypersonic Technology (2 vols.; Wright-Patterson Air Force Base, Ohio: Special Staff Office, 1987). Since these lines were written, another study of Dryden history appeared, Lane E. Wallace's Flights of Discovery: 50 Years at the Dryden Flight Research Center (Washington, D.C.: NASA SP-4309, 1996). Based on an earlier version of Wingless Flight and an interview with Dale Reed, this short history devotes considerable attention to the lifting-body story.


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