December 14, 2001
The Saga of the Bell X-2
by James R. Appleton Ph.D.
Assembly Room, A. K. Smiley Public Library
1941, a serious control problem struck two new US fighters, the Lockheed P-38 and Republic
P-47. This experience stimulated wide interest in the behavior of aircraft at high speed
and triggered a long series of experimental aircraft. The introduction of the jet engine
emphasized this need even further. In 1947 Chuck Yeager became the first person to break
the sound barrier by reaching Mach 1.06. After a long series of tests the Bell X-2 finally
reached Mach 3.2 in September 1956.
Biography of James Appleton
James R. Appleton was named eighth president of the University of Redlands in September
Prior to this he served for 15 years at the University of Southern
California as a member of the faculty, as vice president for student affairs and then as
vice president for development. Before 1972 he served in various faculty and
administrative positions at Oakland University in Rochester, Michigan.
Dr. Appleton currently serves on several boards and committees
outside the University of Redlands. He is serving a three-year term as Chair of the
Western Association of Schools & Colleges Accrediting Commission for Senior Colleges
and Universities and served for many years on the executive committee of the board of the
Washington-based National Association of Independent Colleges and Universities and the
President's Council of NCAA. He was recently elected to the Board of Directors of
Redlands Centennial Bank.
Most recently by invitation Dr. Appleton participated as faculty at a
Symposium on Universities and Social Transformation sponsored by the prestigious Salzburg
Seminars Universities Project. Subsequently, he was named to their Visiting
Advisors Program, which is composed of senior level educational leaders who provide advice
and recommendations on specific institutional concerns and challenges to universities
primarily in Eastern and Central Europe.
He received his undergraduate degree from Wheaton College,
Illinois. His Ph.D. is from Michigan State University.
THE SAGA OF THE BELL X-2
In 1941, a new and serious high speed stability and control
problem struck two new US fighters, the Lockheed P-38 and Republic P-47 Thunderbolt,
during their high speed tests from high altitude. As the aircraft accelerated in the dives
they began to shake, mildly at first, then more violently and control forces became heavy.
Even worse, the controls became ineffective, and the aircraft wanted to nose down further
and increase the severity of the dive.
This experience stimulated wide interest in the behavior of
aircraft at high speed and triggered a long series of experimental aircraft. The
introduction of the jet engine emphasized even further the need for investigation about
transonic flight and an understanding about how to deal with the shockwave phenomena
(physical manifestations of the compressibility of air) experienced at high speeds.
In 1944, negotiations were begun by the National Advisory
Committee for Aeronautics (NASA), the forerunner of NASA, with Bell Aircraft that
eventually led to the Bell X-1. During the 13th flight in the X-1 on 14 October
1947, Captain Chuck Yeager, now a familiar name in aeronautics experimentation, became the
first person to break the "Sound Barrier" by reaching Mach 1.06. "American
research aircraft continued through variants of the Bell X series including the Bell X-1A
(Mach 2.44, in December 1953); the Bell X-2 (Mach 3.2, in September 1956) and the highly
successful North American X-15 (Mach 6.73, in October 1967)."
It is the X-2 that is the focus of this paper: on one hand a
highly successful transition model, and yet at the same time a deeply troubled and tragic
project. It began in 1945 and ended in 1956. Its objectives - to reach speeds of over Mach
3 and altitudes over 100,000 ft. Before the Space Shuttle, there was the X-15, and
before the X-15 there was the X-2. This winged missile, barely wide enough to house a man
but harnessing enough power to drive a navy cruiser, went higher and faster than any
airplane before. It extended mankind's reach toward space and was in a way a prototype of
the winged space vehicles to follow. It was indeed the first of the spaceships and a
tragic but heroic milestone in the conquest of space.
"On 14 December 1945
signed a contract for the development,
construction, and initial flight test of two X-2 supersonic swept-wing research
aircraft." NACA was present to give its blessing to the project. Its innovative swept
wing design was envisioned as being able to attain greater Mach speeds, and having the
ability to withstand gust and air turbulence at high speeds, thereby expanding beyond the
expectations set for the X-1. After further studies by both the Navy and Air Force that
investigated the swept-wing concept, a contract was officially received by Bell on July 3,
The early development work of assembling major components,
construction of the fuselage and wing panels, installation of fuel tank assembly, power
plant, pilot compartment, and instrumentation proceeded on two X-2s (46-675 and 46-674)
during 1949 at Bell's Wheatfield plant near Niagara Fall, New York. The copy numbered
46-675 was the first to undergo vibration tests, structural tests of the wing and
fuselage, and landing gear tests and "on 11 November 1950 rolled out without its
rocket engine from Bell's Wheatfield plant." The X-2 was approximately 38 ft.
long and 32 ft in wing span
to its small size, the cockpit was equipped with control panels counting miniature
. It had a nose wheel and an unconventional landing gear which consisted
of a retractable one-foot wide main landing skid
Small skids were affixed to the
wings to avoid wingtip damage in landing. At the same time, a EB-50A bomber was being
modified by cutting away a part of the bomb bay so that the X-2 could be fit snugly
underneath the main body of the plane. The X-2 was to be lifted into the air under the
bomber, released in midair by a lever in the cockpit, launched, and then fired in air.
"For loading the X-2, the bomber was first hoisted on 20-ton hydraulic lifts, then
the X-2 was moved on its dolly beneath the bomber's wing. The bomber was lowered back to
the ground and the X-2 shackled into position."
The powerplant contract, the rocket engine, was awarded to Curtiss-Wright Corporation, not
to Bell Aircraft.
Curtiss-Wright had very little experience with rockets, but by
August 1947 the design had been completed and building had begun. Numerous problems
plagued the engine and it was not until 1953 that the first flight worthy unit was
delivered. As originally developed the Curtiss-Wright XL R25 was an extremely
temperamental unit, suffering numerous test stand explosions and modification and
refinement took eight years to complete.
The propellants were ethyl alcohol as fuel and liquid oxygen as
oxidizer. "Several factors influenced the selection of these propellants. They had to
have the maximum energy possible for the minimum total weight. Safety in handling and
long-time storage ability were essential and the propellants' corrosive and toxic
tendencies had to be as low as possible. Availability and cost also played a major role in
the selection." Each combustion chamber of the engine was started by a spark plug.
BRIEF CAREER OF THE X-2 46-675
Captive flights with the X-2 46-675 began in July 1951 over
Buffalo, with the X-2 being flown mated to its carrier aircraft and the engine weight
replaced by ballast. These flights were designed to give experience in loading the pilot
from the carrier into the X-2, to check out launch procedures, to check out the X-2
systems, and to establish necessary techniques for making the drop. The first series of
these captive flights ended in early 1952 and in April the 46-675 was delivered to Edwards
AFB, California, for further ground testing and captive flights prior to its free
Edwards had been the home of Air Force, Navy and NACA flight testing for
several years and its flat landscape provided the isolation and remoteness necessary in
advanced high-speed/altitude flying. The vast expanse of its dry-lake bed afforded ample
The first manned captive flight was made on June 5, 1952 with
Chief Test Pilot Jean L "Skip" Ziegler at the controls and it was judged at that
time that "the X-2 was ready for glide flight testing." On June 27, 1952, the
first free flight, with ballast replacing the additional successful free flights were made
on October 10, but on October 18, in an effort to improve the landing gear, the aircraft
was ferried back to Bell's Wheatfield facility. By early 1953, both X-2 models were ready
for engine installation. The X-2 46-675 was fitted with an engine. In March, captive
flights with this aircraft resumed to test propellant dump and tubopump exhaust tests. The
outlook was promising but the first tragedy was in store for the program.
On 12 May 1953, the engine-equipped X-2 was mated to its carrier
aircraft and flown from Bell's Wheatfield plant over adjacent Lake Ontario to check the
liquid oxygen topoff and jettisoning procedures
The operation began smoothly and the
liquid oxygen tank was topped and drained successfully. The required nitrogen
pressurization of the tank had begun and just after the pressure had reached normal
operating values, the X-2 exploded and a large ball of flames engulfed the rocketplane and
its mothership, 30,000 ft. over the center of Lake Ontario. The pilot was still in the
bomb bay of the carrier preparing to enter the X-2.
The X-2 disintegrated, a scanner in the rear of the carrier and
the test pilot Ziegler were never found, but the carrier crew managed to land with only
modest damage to the mother ship. It was only much later, in 1955, after a similar
explosion destroyed one of the X-IA's that it was determined that the leather used in the
construction of liquid oxygen tank gaskets, an organic substance, and liquid oxygen unites
chemically with explosive violence with any organic substance under the shock of a
triggering impact. At the time of the explosion, the plane was banging and vibrating with
a force that was
enough to detonate the explosive mixture. These leather gaskets were replaced with ones
made of lead, Flexitallic and Teflon in the other X-2 model.
"By now six years of work and six million dollars had been
spent. And, there remained only one model of the X-2." There was at this point
considerable doubt about the remaining X-2 ever making a powered flight. And, the
modifications continued. For example, "three inches were added to the length of the
fuselage, weight was added to the aft section to maintain the former center of gravity.
Steel hemispheric bowls replaced the original wingtip bumper skids." This illustrates
the continued experimentation into unknown and new territory, unknown futures, painstaking
work and sometimes without a
clear understanding of the best solutions until after one could demonstrate the effects.
More than a year was required for these modifications and testing, and modifications of
the rocket engine performance. On July 15 1954 the X-2 46-674 was ferried to Edwards Air
Force Base for the next stages.
THE TESTING CONTINUES
"With Ziegler dead and no other civilian pilots with comparable experience available,
Lt. Col. Pete Everest volunteered to carry out the test flying." The first glide
flight was undertaken on August 5, 1954. The drama must have been intense, given the
experiences to date. "When all was set, the leader of the carrier crew reached down
beside his seat and removed the safety pin on the drop handle. Then he said 'ready to
drop' into the open radio circuit, which was being monitored by Everest in the X-2 and by
the chase aircraft, and Everest signaled that he was ready." With ballast replacing
the propellant weight, the X-2 was dropped at 30,000 ft so that Everest could check its
new hydraulic control system. The drop was made without incident at 220 mph, with Chuck
Yeager as the chase pilot."
"On touchdown, the steerable nosewheel turned 45 degrees to
the right and the right whisker skid had not extended." The plane swerved to the
right, "the nose yawed off repeatedly to one side and the other, slamming the
wingtips into the ground and scraping the desert floor. The left wingtip then dug into the
lakebed causing the airplane to pivot to the left
Though damage was minor, both
wingtips were bent and the nosewheel strut was wedged in the nosewheel well."
So back to New York again, where the instrumentation was
inspected. Some gages were replaced and other modifications made. The decision was made to
proceed with three more glide flights, and then to the powered experiments. The objectives
were reiterated. "The X-2 was to be furnished to the NACA for use as a research
vehicle to obtain data on high speed flight as an aid in the design of future operational
aircraft. Flight testing was to determine the acceptability of the aircraft as an
Back at Edwards, after four more captive flights, the Air Force publicly announced that
the X-2 was ready to be test-flown at Edwards AFB. Test five was a drop without ignition -
successful except upon landing it again slid out of control left then right and came to a
halt on its right wingtip. "Faced with Everest's harsh complaints from the dangerous
touchdown characteristics, Bell on 8 April ferried the X-2 again back to Wheatfield, where
engineers spent months on repairs and on investigation of the landing problem using
comprehensive tests on a dynamically scaled model." They reduced the height of the
main skid, modified the sinking speed of the aircraft, and increased the width of the main
skid. The X-2 arrived back at Edwards on July 21, 1955.
A PERSONAL PART OF THE SAGA
This brings me to a personal part of the story but I'll have to backtrack just a bit. In
1952, Bob Appleton, my father, was seeking new employment. As the oldest of 6 children in
this post-depression family, I was then 15 years old, had just graduated from high school,
and can recall these days more vividly than my younger siblings. We lived in North
Tonawanda, New York, between Buffalo and Niagara Falls, which sits at the Intersection of
the Niagara River and the storied Erie Canal. It was then an industrial, working class
town, that slipped from logging and paper mills, to steel production that
peaked during World War II, to chemical companies, to a town of massive unemployment by
the early '50s. My father was employed for a long time at the Buffalo Bolt Company as an
expeditor, and in the evening as partner in a photographic studio. As Buffalo Bolt began
to close, those large plants now just decaying ghosts of the past, my Dad looked for the
next employment opportunity to sustain his large family. He was a talented man who had
aspired to be a physician but without opportunity during the great depression to realize
such dreams. A Bell Aircraft engineer suggested he apply at the Bell plant in Wheatfield.
He was successful in securing a position that led to his working on the X-2 project.
As the X-2 was shipped back and forth from Edwards and the Bell plant in Wheatfield,
personnel were required for operation of the engine test stands that experimented with the
engine and propellants outside of the fuselage of the X-2 itself as well as the live
exercises. The record shows that a number of Bell employees over time were temporarily
transferred to Edwards: supervisors, engineers, technicians, propellants experts,
mechanics, and inspectors. In many instances, their families moved with them. When the X-2
returned to Edwards this time, July 21, 1955 additional Bell personnel were
required and Bob Appleton, now a trained propellants expert and master mechanic, was
included. His understanding of valves and systems, and his ability to manufacture a
solution to just about any mechanical problem, seemed to fit the modality adapted in this
I can recall my family leaving on August 10, 1955 in a packed
1954 Chevy station wagon, blue with the old wood side panels, for their week-long trek
across the country, not unlike the early pioneers, or maybe the image was closer to the
Beverly Hillbillies. I had finished one year in college and employed for the summer in
North Tonawanda, so remained behind to later travel once more to Illinois for my sophomore
year. Several families moved from the gray and somewhat depressed location that had been
their locale for generations into rented homes in a modest subdivision in Palmdale
surrounded by Joshua Trees and cactus and sun and double shifts. The men drove the 60
miles crisscrossing the desert for 12 to 16 hour workdays. The wives and families bonded,
the kids became friends, and they thrived in believing they were part of something very
exciting and important that they didn't quite understand because of the classified nature
of the project. What they did know, they kept under security wraps.
NOW BACK TO THE X-2
By October 1955 the X-2 programme was in deep trouble, with an increasing loss of
credibility. A limit was set; the X-2 had to make a successful powered flighty by the end
of the year or the Air Force would cancel it. Working against this three-month deadline,
Everest and Bell decided to go for a powered flight before checking out the new
undercarriage. This was a double hazard and many thought, little short of foolhardy.
However, desperation had grown within the X-2 programme, with more risks taken than in
normal circumstances. It could be the last chance to fly, after ten years with little
positive to show, two lives lost and expenditures of nearly 16 million 1950's dollars,
well over the original estimates.
This may be an appropriate juncture to comment about the role of these test pilots. They
played a bigger role in managing the process and recommending minute-by-minute changes in
all aspects of the program than we might imagine at first glance. As well, as they faced
the unknown at such dizzying speeds, there was a mystique that grew up around them. The
technicians who worked with them were on one hand awed at their skill and daring and at
the same time thought of them as test pilot cowboys.
Parenthetically, the project itself and the story of the test
pilots were chronicled in a feature film titled Toward the Unkown with stars William
Holden, Virginia Lee, and Lloyd Nolan. As you might imagine, my family watched this film
occasionally over the years. "On October 25 1955 with the engine installed and with
enough propellants on board, Everest attempted a first powered flight." Noting
nitrogen leakage, the propellants were jettisoned, the powered flight aborted, and the X-2
made a glide flight with a successful touchdown on the new landing gear strut. On November
18 - the date finally arrived - following the careful review of a 127-item checklist,
Everest tested the controls and the drop was made at 30,000 ft. "Repeated attempts at
ignition failed to get more than intermittent operation and only a speed of Mach .95 was
achieved. During a gentle climb, a small fire broke out in the rocket engine and
fortunately quickly extinguished itself." But, rocket power had been used for the
first time on this project and the Air Force was convinced that the program should
continue. More repairs once more solved the problem that had emerged on this first powered
flight and after two more aborted flights because of malfunctions, on March 24, 1956,
Everest successfully made the second powered flight. The X-2 attained Mach .91 and 45,000
ft. This time only the 10,000 lb. chamber fired, the 5,000 lb. chamber failed
to fire despite repeated attempts.
"The first supersonic flight was realized on April 25 with
both chambers operating. Mach 1.4 and a maximum altitude of 50,000 ft were achieved. The
total flight time was 13.5 minutes. Then in rather quick succession, the second and third
supersonic flights were achieved with the last achieving Mach 1.8 during a dive from
60,000 ft to 55,000 ft. There still were doubts that the X-2 would ever reach its design
speed but it was expected that Everest would extend the speed envelope on each successive
Then another ill-fated move. For reasons that are not very clear, Everest, the only
experienced test pilot on this project, was about to be reassigned to another position.
Captain Iven C. Kincheloe joined the X-2 team. In his first flight, now the seventh
powered flight and the fifth supersonic flight, Kincheloe shut the rocket engine
prematurely but still achieved supersonic speed and reported that the control and response
were better than he expected.
Following my sophomore year in college, I flew to Palmdale for
the summer of 1956. I worked at a sand and gravel company and sold Electolux vacuum
cleaners door to door. And I listened to my father's tales about the simulated flights and
then the actual flights on the dry lake. On a given flight, I believe the one just noted,
he decided he had the necessary clout to take me to the test site. The day started well
before the first light - fitting the X-2 under the mother ship, adding propellants,
working the long list of checks
that now seemed routine for the mechanics and crew. We watched with binoculars the drop
from the mother ship, the long smoke trials that began with ignition, the chase planes in
hot pursuit. Before long I was riding a vehicle to the recovery area to see the long
glide, skid marks in the sand, and the test pilot helped from the extremely tight
quarters. Ground crews scurried to look at the burn marks at various places on the
fuselage and to examine every inch of the ship. The sense of ownership on the part of each
person, from test pilot to mechanic was obvious.
Following each flight, adjustments were made again and components
replaced in the engine. At this juncture in the experimentation, temperature-sensitive
paint stripes were added to the frame, allowing engineers to measure the amount of heat
caused by air friction. The plane was coated with a white resin type paint.
Instrumentation was installed to record temperatures in the engine compartment during
flight. Ground tests continued on the test stands at Edwards.
Everest returned for the sixth supersonic flight on July 12. The
engine cut out at Mach 1.5. He then made his final flight operating the rocket engine at
full thrust and achieved Mach 2.8706 in a 14 minute and 50 second flight - a record speed
- no man had ever flown faster. After two more aborted flights for various control
malfunctioning, Kinchloe completed two successful flights reaching Mach 2.58 in one. Then
on September 7, 1956, in his last flight in the X-2, Kincheloe successfully achieved a
world altitude record of 126,200 ft.
TRAGEDY BRING THE PROJECT TO AND END
Inserting yet another pilot into the project, "Captain Milburn Apt was chosen as the
Air Force's new X-2 pilot. He had flown chase for Kincheloe's flights and had been checked
out on cockpit procedures in several rocket ground runs." The Air Force was still
determined to get the optimum maximum energy flight path and to exceed Mach 3 with the X-2
and pushed ahead with these plans. "On 26 September, the X-2 was maintained ready for
flight again. A pre-flight meeting was held at the Bell facility during which the Air
force, NACA and Bell representatives agreed on a flight plan.
Preparations for the flight began at dawn the next day. The plane
took off at 0745 hours on the morning of September 27, 1956. At 7,000 ft. Apt headed to
the bomb bay, where technicians helped him cinch up his pressure suit and strap on his
parachute." He lowered himself into the cockpit with only an inch or two clearance
above his helmet. The heavy canopy was closed and locked and Apt went through his
pre-launch ckecklist as topping off of the X-2's LOX tank was completed. (these paragraphs
drawn heavily from Matthews pgs. 57 and 58.)
At 0849 the X-2 separated from the mother ship and Apt brought
both rocket chambers into operation at full thrust. He began his climb and became
supersonic at 43,000 ft. Mach 2 was reached at 50,000 ft. He was precisely on the
right climb and reached 67,000 ft altitude 141 seconds into the climb. At Mach 2.2 and
72,000 ft level, Apt pushed over into a shallow dive at full throttle. The X-2, gravity
aiding its rocket thrust, sped ahead even faster and achieved Mach 3.196, the fastest
speed ever achieved by man.
In a calm voice he radioed: "O.K. The engine has cut out and I'm beginning to
Then suddenly, radio listeners heard the calm voice rise to an
unintelligible shriek. As listeners waited and worried, Kincheloe who was flying chase
yelled repeatedly on the radio, "Mel do you read me?" In the following 16
seconds, the X-2 went completely out of control, dropping 40,000 ft. Apt fought to regain
control of the X-2 but the plane pitched sharply, yawing from side to side, rolling over
on its back, righting itself and rolling again. The cockpit camera showed Apt being tossed
wildly about, his head slamming against the side of the canopy. He caught the handle that
would jettison the nose section capsule from the plane by an explosive charge. The capsule
separated and tumbled end over end, slamming Apt back and forth and subjecting his body to
tremendous g forces. The parachute on the capsule did open and the capsule righted, but
the parachute was designed only for stability and was too small to lower the capsule
gently. Apt had to bail out from the capsule to escape, but he was probably too dazed and
he slammed into the desert floor and died on impact.
The investigations of the crash were very thorough. It is likely
that when Apt made his turn he was traveling at such a high speed that he simply lost
control. Experts stated later that he likely underestimated his rate of speed. He should
have waited longer to make the turn after the engine had shut down. It was never
satisfactorily explained why Apt, an experienced test pilot but with no flight experience
on rocket aircraft, was allowed to launch on an exacting mission like the one that doomed
him without more simulated and real but less demanding flights. Fatigue in a program that
had lasted so long beyond original timelines, miscalculations, and poor judgement all
entered into the program at a time when unhurried flights were in order.
MORE THAN THE CLOSE OF AN AEROSPACE PROJECT
The abrupt close of the X-2 program also brought an abrupt end to the California odyssey
for the families of the X-2. They grieved for the pilots, the lost opportunities; they
felt the grief as if they had lost someone in their own family. The men were provided jobs
at the Wheatfield plant and Bob Appleton and his family, less their eldest son, joined the
rest and in October made the journey eastward again, this time via a long vacation through
Florida. It was clear very soon that the job situation at Bell was insecure and temporary.
With one of the Appleton children having serious difficulty with eczema since the return
to the New York climate and pollens, and having enjoyed the excitement of the sunny west,
Bob Appleton considered a more permanent move to the west coast.
His experience on the X-2 brought an offer from one of the large
aerospace industries. In May of 1952, he drove cross country once more to purchase a house
and get ready to welcome his family who would fly back in June. Given the nature of the
aerospace industry that might have been illustrated by the saga of the X-2 itself,
employment in a booming industry still depended upon which large corporation, e.g. Convair
or North American, had the government contract, which subcontractors successfully bid the
work, and what projects survived. Bob Appleton was always employed in the industry - from
one test stand to another, or developing some part that would be fitted into the latest
modification of some rocket engine, retrofitting an old part for a new use, or using his
mechanical genius to figure out what valve or hookup might work just a bit better. But
never with excitement and sense of importance that was a fringe benefit of working on the
cutting edge of rocket technology that would lead to space exploration.
He, like the others in these projects, regretted the loss of test pilots he knew
personally. but might have secretly visualized himself in that role. He, like the others,
also recognized that the financial costs, but they seemed inconsequential when compared to
moving American aerospace technology to a new plateau.
In hindsight, the experts found it easy to identify what went wrong with the X-2 program
and condemn the loss of lives and the planes. No program caused NACA more frustration and
disappointment. "It suffered endlessly recurring propellant leaks, turbopump and
ignition problems." Records show that NACA engineers had pleaded for caution on the
part of the Air Force. There were times when NACA regarded the X-2 program as "a
disaster masquerading as research." They wanted the Air Force to move in smaller Mach
increments, they questioned why a pilot with limited experience was not allowed at least
one familiarization flight, and historians accused the Air Force of "succumbing to
the pressure of inter-service rivalry to set records." One historian R.P. Hallion
went so far as to state that "the X-2 program was an unqualified failure, despite
achieving both altitude and speed records." A long list of lessons to be learned,
most of them focusing on process and protocols, was assembled in an effort to avoid the
cost overruns, the loss of time, the loss of lives and material in later projects.
Yet, the data gathered from studying the previously untried materials, the experience with
the swept wing design, the development of the innovative engine, and the use of new
propellants all moved the supersonic era to the next levels. The stability and control
information gathered led to further design sophistication.
"Although plagued by accidents and delays, the X-2 program
produced several accomplishments:
1. The problems of high speed and high altitude flight in a piloted aircraft were
investigated, analyzed, and to a great measure, solved.
2. Aerodynamic design problems relative to high speed and high altitude flights were
investigated and resolved.
3. New records of high speed and altitude flight in a piloted aircraft were established.
4. Aerodynamic heating problems generated by high-speed flight was investigated.
5. A gyro platform was developed for incorporation into future high-speed aircraft which
would be a source of altitude and rate information.
6. The use of a radio link for climb angle, speed, altitude, and flight locations was
7. Cockpit presentation schemes were developed for future high performance aircraft."
And the X-2 paved the way for the X-15 series that in November 1966 flew at Mach 6.33
nearly twice the X-2's maximum speed. This in turn led to the technology that sent
unmanned and manned vehicles into the upper atmosphere, into outer space, and beyond
earth's gravity. But, that's a story for another time.
Hallion, R.P., On the Frontier: Flight Research at Dryden, 1946-1981, NASA SP-4303, 1984.
Matthews, Henry. The Saga of the Bell X-2: First of the Spaceships The Untold Story, HPM
Publications, Beirut, Lebanon, 1999.
Whitfield, Ray, Bell X-2, AIR International, August 1996
Whitfield, Ray, Bell X-2, AIR International, September 1996
Whitfield, Ray, "Lessons Learned from the Bell X-2 Program," 1997 World Aviation
Congress, October 13-16, 1997, Anaheim, CA. Published by the American Institute of
Aeronautics and Astronautics at 1801 Alexander Bell Drive, Reston VA 22091.
Whitford, Ray, "Supersonic Man Is Fifty," Aircraft Engineering and Aerospace
Technology, Vol. 70, Number 1, 1998, pp.15-23.
Various Web Site references