Tag Archives: Bell X-1A

12 December 1953

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Bell X-1A 48-1384 in flight. The frost band on the fuselage shows the location of the cryogenic propellant tank. (U.S. Air Force)

12 December 1953: On its tenth flight, U.S. Air Force test pilot Major Chuck Yeager flew the Bell X-1A rocket plane to Mach 2.435 (1,618 miles per hour/2,604 kilometers per hour) at 74,700 feet (22,769 meters), faster than anyone had flown before.

After the rocket engine was shut down, the X-1A tumbled out of control—”divergent in three axes” in test pilot speak—and fell out of the sky. It dropped nearly 50,000 feet (15,240 meters) in 70 seconds. Yeager was exposed to accelerations of +8 to -1.5 g’s. The motion was so violent that Yeager cracked the rocketplane’s canopy with his flight helmet.

Yeager was finally able to recover by 30,000 feet (9,144 meters) and landed safely at Edwards Air Force Base.

Yeager later remarked that if the X-1A had an ejection seat he would have used it.

Bell Aircraft Corporation engineers had warned Yeager not to exceed Mach 2.3.

Major Charles E. Yeager, U.S. Air Force, seated in the cockpit of the Bell X-1A, 48-1384, circa 1953. (U.S. Air Force)

The following is from Major Charles E. Yeager’s official post-flight report:

After a normal drop at 31,000 feet, chambers #4, #2, and #1 were ignited and [the] airplane was accelerated up to .8 Mach number. A flight path was formed holding .8 Mach number up to 43,000 feet where chamber #3 was ignited and the airplane accelerated in level flight to 1.1 Mach number. A climb was again started passing through 50,000 feet at 1.1 Mach number, 60,000 feet at 1.2 Mach number and a push-over was started at 62,000 feet. The top of the round-out occurred at 76,000 feet and 1.9 Mach number. The airplane was accelerated in level flight up to 2.4 [2.535 indicated] Mach number where all of the rocket chambers were cut. The flight path was very normal and nothing uneventful [sic] happened up to this point. After the engine was cut, the airplane went into a Dutch roll for approximately 2 oscillations and then started rolling to the right at a very rapid rate of roll. Full aileron and opposite rudder were applied with no effect on the rate of roll of the airplane. After approximately 8 to 10 complete rolls, the airplane stopped rolling in the inverted position and after approximately one-half of one second started rolling to the left at a rate in excess of 360 degrees per second, estimated by the pilot. At this point the pilot was completely disoriented and was not sure what maneuvers the airplane went through following the high rates of roll. Several very high ‘g’ loads both positive and negative and side loads were felt by the pilot. At one point during a negative ‘g’ load, the pilot felt the inner liner of the canopy break as the top of his pressure suit helmet came in contact with it. The first maneuver recognized by the pilot was an inverted spin at approximately 33,000 feet. The airplane then fell off into the normal spin from which the pilot recovered at 25,000 feet.

Flight test data from Yeager's 12 December 1953 flight superimposed over a photograph of the bell X-1A. (NASA)
Flight test data from Yeager’s 12 December 1953 flight superimposed over a photograph of the Bell X-1A. (NASA)

The following is a transcript of radio transmissions during the flight:

Yeager: Illegible [inaudible]—gasping—I’m down to 25,000 over Tehachapi. Don’t know
whether I can get back to the base or not.
Chase (Ridley): At 25,000 feet, Chuck?
Yeager: Can’t say much more, I got to (blurry—save myself).
Yeager: I’m—(illegible)—(Christ!)
Chase (Ridley): What say, Chuck?
Yeager: I say I don’t know if I tore anything up or not but Christ!
Chase (Murray): Tell us where you are if you can.
Yeager: I think I can get back to the base okay, Jack. Boy, I’m not going to do that any more.
Chase (Murray): Try to tell us where you are, Chuck.
Yeager: I’m (gasping)…I’ll tell you in a minute. I got 1800 lbs [nitrogen] source pressure.
Yeager: I don’t think you’ll have to run a structure demonstration on this damned thing!
Chase (Murray): Chuck from Murray, if you can give me altitude and heading, I’ll try to check you from outside.
Yeager: Be down at 18,000 feet. I’m about—I’ll be over the base at about 15,000 feet in a minute.
Chase (Murray): Yes, sir.
Yeager: Those guys were so right!
Yeager: Source pressure is still 15 seconds, I’m getting OK now.
Yeager: I got all the oscillograph data switches off. 4 fps camera off, it’s okay.
Bell Truck: Jettison and vent your tanks.
Yeager: I have already jettisoned. Now I’m venting both lox and fuel. Leaving hydrogen peroxide alone.
Bell Truck: Roger.
Yeager: I cut it, I got—in real bad trouble up there.
Yeager: Over the base right now, Kit, at 14,500 feet.
Chase (Murray): I have you.

A North American F-86E-10-NA Sabre chase plane, 51-2848, follows the Bell X-1A as it glides toward Rogers Dry Lake. (NASA)
A North American F-86E-10-NA Sabre chase plane, 51-2848, follows the Bell X-1A as it glides toward Rogers Dry Lake. (NASA)

In his autobiography, Always Another Dawn, NACA test pilot Albert Scott Crossfield wrote:

Probably no other pilot could have come through that experience alive. Much later I asked Yeager, as a matter of professional interest, exactly how he regained control of the ship. He was vague in his reply, but he said he thought that after he reached the thick atmosphere, he had deliberately put the ship into a spin.

“A spin is something I know how to get out of,” he said. “That other business— the tumble—there is no way to figure that out.”

. . . Yeager received many accolades. I didn’t begrudge him one of them. If ever a pilot deserved praise for a job well done, it was Yeager. After that X-1A episode, he never flew a rocketplane again.

—Always Another Dawn: The Story of a Rocket Test Pilot, by A. Scott Crossfield with Clay Blair, Jr., The World Publishing Company, Cleveland and New York, Chapter 19 at Pages 183–184.  

Bell X-1A 48-1384 (U.S. Air Force)

The Bell X-1A, 48-1384, was an experimental rocket-powered high-speed, high-altitude research aircraft. It was one of four second-generation X-1s (including the X-1B, X-1D and X-1E), specifically designed to investigate dynamic stability at speeds in excess of Mach 2 and altitudes greater than 90,000 feet. It was a mid-wing monoplane with retractable tricycle landing gear. The airplane was 35 feet, 6.58 inches (10.835 meters) long with a wingspan of 30 feet, 6 inches (9.296 meters) and overall height of 10 feet, 2.37 inches (3.261 meters). The wheelbase, measured from the nose wheel axle to the main wheel axle, was  13 feet, 5.13 inches. (4.093 meters). The main wheel tread was 4 feet, 3 inches (1.295 meters). The X-1A design gross weight was 10,668 pounds (4,839 kilograms).

The X-1A was powered by a single Reaction Motors XLR11-RM-5 rocket engine with four independent combustion chambers. The XLR11 was fueled with ethyl alcohol and liquid oxygen. It produced 6,000 pounds of thrust (26.689 kilonewtons).

The Bell X-1A made its first flight 14 February 1953 with Bell test pilot Jean Ziegler in the cockpit. It reached its highest speed, Mach 2.44 on Flight 10. Its highest altitude was 90,440 feet (27,566 meters) on its 24th flight. On 8 August 1955, while still on board its B-50 drop ship, the X-1A suffered an external explosion. The rocketplane was jettisoned and destroyed when it hit the desert floor.

© 2016, Bryan R. Swopes

8 August 1955

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8 August 1955: While being carried aloft by a Boeing B-29 Superfortress, the Bell X-1A was being readied for it’s next high-altitude supersonic flight by NACA test pilot Joe Walker. During the countdown, an internal explosion occurred. Walker was not injured and was able to get out. The X-1A was jettisoned. It crashed onto the desert floor and was destroyed.

A number of similar explosions had occurred in the X-1D, X-1-3 and the X-2. Several aircraft had been damaged or destroyed, and Bell Aircraft test pilot Skip Ziegler was killed when an X-2 exploded during a captive flight. A flight engineer aboard the B-29 mothership was also killed. The B-29 was able to land but was so heavily damaged that it never flew again.

Debris from the X-1A crash site was brought back to Edwards AFB for examination. It was discovered that a gasket material used in the rocket engine fuel systems was reacting with the fuel, resulting in the explosions. The problem was corrected and the mysterious explosions stopped.

Test pilot Joe Walker “horsing around” with the Bell X-1A, 1955. (NASA)

© 2015, Bryan R. Swopes

4 June 1954

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Major Arthur Warren "Kit" Murray, U.S. Air Force, with the Bell X-1A at Edwards AFB, 20 July 1954. Major Murray is wearing a David Clark Co. T-1 capstan-type partial-pressure suit with a K-1 helmet. (NASA)
Major Arthur Warren “Kit” Murray, U.S. Air Force, with the Bell X-1A at Edwards AFB, 20 July 1954. Major Murray is wearing a David Clark Co. T-1 capstan-type partial-pressure suit with a K-1 helmet. (NASA)

4 June 1954: at Edwards Air Force Base, California, Major Arthur W. “Kit” Murray flew the experimental Bell X-1A research rocketplane to an altitude of 89,810 feet (27,374 meters). He flew high enough that the sky darkened and he was able to see the curvature of the Earth. Newspapers called him “America’s first space pilot.”

The X-1A reached Mach 1.97. Encountering the same inertial coupling instability as had Chuck Yeager, 20 November 1953, though at a lower speed, the X-1A tumbled out of control. The rocket plane lost over 20,000 feet (6,100 meters) altitude before Murray could regain control. For this accomplishment, Major Murray was awarded the Distinguished Flying Cross.

One week earlier, 28 May 1954, Murray had flown the X-1A to an unofficial world record altitude of 90,440 feet (27,566 meters).

Arthur Murray, 1936. (The Argus)

Arthur Warren Murray was born at Cresson, Cambria County, Pennsylvania, 26 December 1918. He was the first of two children of Charles Chester Murray, a clerk, and Elsie Espy Murray.

Arthur Murray attended Huntingdon High School, Huntingdon, Pennsylvania, graduating 4 June 1936, and then studied Juniata College, also in Huntingdon, 1937–1938.

Arthur Murray, 1938. (The Nineteen Thirty-Seven Alfarata)

Kit Murray enlisted in the Field Artillery, Pennsylvania National Guard, 17 November 1939. (Some sources state that he served in the U.S. Cavalry.) Murray had brown hair and blue eyes, was 5 feet, 10 inches (1.78 meters) tall and weighed 150 pounds (68 kilograms). Following the United States’ entry into World War II, Sergeant Murray requested to be trained as a pilot. He was appointed a flight officer (a warrant officer rank), Army of the United States, on 5 December 1942. On 15 October 1943 Flight Officer Murray received a battlefield promotion to the commissioned rank of second lieutenant, A.U.S.

Between 6 January  and 22 October 1943, Murray flew over 50 combat missions in the Curtiss-Wright P-40 Warhawk across North Africa. After about ten months in the Mediterranean Theater, he returned to the United States, assigned as an instructor flying the Republic P-47 Thunderbolt fighter bomber, stationed at Bradley Field, Hartford, Connecticut.

Republic P-47 Thunderbolts at Bradley Field, Connecticut, 9 September 1944. (U.S. Air Force)

Lieutenant Murray married Miss Elizabeth Anne Strelic, who had immigrated from Czechoslovakia with her family as an infant, at Atlantic City, New Jersey, 29 December 1943. They would have six children, and foster a seventh. They later divorced. (Mrs. Murray died in 1980.)

Lieutenant and Mrs. Arthur W. Murray, 1943. (Murray Family Collection)

Murray was promoted to 1st lieutenant, A.U.S., 8 August 1944. His next assignment was as a maintenance officer. He was sent to Maintenance Engineering School at Chanute Field, Rantoul, Illinois, and from there to the Flight Test School at Wright Field, Dayton, Ohio.

Murray was the first test pilot to be permanently assigned to Muroc Army Air Field (later, Edwards Air Force Base). Other test pilots, such as Captain Chuck Yeager, were assigned to Wright Field and traveled to Muroc as necessary.

Murray’s A.U.S. commission was converted to first lieutenant, Air Corps, United States Army, on 19 June 1947, with date of rank retroactive to 15 October 1946. The U.S. Air Force became a separate military service in 1947, and Lieutenant Murray became an officer in the new service.

Major Arthur Warren (“Kit”) Murray, United States Air Force, with a Northrop F-89 Scorpion interceptor, 1954. (The New York Times)

Murray was involved in testing new Air Force fighters such as the Bell P-59 Airacomet, Lockheed P-80 Shooting Star, Republic P-84 Thunderjet, McDonnell XF-88 Voodoo; and the Douglas XB-43 Jetmaster and North American Aviation B-45 Tornado jet bombers. He also flew the experimental aircraft such as the X-1A, X-1B, X-4 and X-5. Murray spent six years at Edwards before going on to other assignments.

Colonel Arthur Warren (“Kit”) Murray, U.S. Air Force.

Later, 1958–1960, Major Murray was the U.S. Air Force project officer for the North American Aviation X-15 hypersonic research rocketplane at Wright Field.

Colonel Murray retired from the U.S. Air Force in 1961. He next worked for Boeing in Seattle, Washington, from 1961 to 1969, and then Bell Helicopter in Texas.

On 4 April 1975, Kit Murray married his second wife, Ms. Ann Tackitt Humphreys, an interior decorator, in Tarrant County, Texas.

Colonel Arthur Warren Murray, United States Air Force (Retired), died at West, Texas, 25 July 2011, at the age of 92 years.

NASA 800, a highly modified Boeing B-29 Superfortress, carries the Bell X-1A to altitude over Edwards AFB. (NASA)
A highly modified Boeing B-29 Superfortress carries the Bell X-1A to altitude over Edwards AFB. (U.S. Air Force)

The Bell X-1A was a follow-on project to the earlier X-1. It was designed and built by the Bell Aircraft Corporation at Buffalo, New York, to investigate speeds above Mach 2 and altitudes above 90,000 feet (27,432 meters). It was carried to altitude by a modified Boeing B-29 Superfortress, then dropped for the research flight.

The rocketplane was 35 feet, 7 inches (10.846 meters) long with a wingspan of 28 feet (8.534 meters) and overall height of 10 feet, 8 inches (3.251 meters). It had an empty weight of 6,880 pounds (3,120.7 kilograms) and gross weight of 16,487 pounds (7,478.3 kilograms).

The X-1A was powered by a Reaction Motors XLR-11-RM-5 four-chamber rocket engine which produced 6,000 pounds of thrust. It had a maximum speed of Mach 2.44 (Yeager) and reached an altitude of 90,440 feet (27,566.1 meters) (Murray).

Bell X-1A 48-1384. (U.S. Air Force)
Bell X-1A 48-1384. (U.S. Air Force)

The X-1A was destroyed by an internal explosion, 20 July 1955.

© 2018, Bryan R. Swopes

12 May 1953

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Jean L. "Skip" Ziegler, with the Bell X-5 at Edwards Air Force Base, 1952. (LIFE Magazine via Jet Pilot Overseas.
Jean LeRoy “Skip” Ziegler, with the Bell X-5 at Edwards Air Force Base, 1951. (LIFE Magazine)

12 May 1953: A Boeing B-50A-5-BO Superfortress, 46-011, modified to carry a Bell X-2 supersonic research rocketplane, was engaged in a captive test flight at 30,000 feet (9,144 meters) over Lake Ontario, between Canada and the United States. The number two X-2, 46-675, was in the bomb bay.

The bomber was equipped with a system to keep the X-2’s liquid oxygen tank filled as the cryogenic oxidizer boiled off. With Bell’s Chief of Flight Research, test pilot Jean Leroy (“Skip”) Ziegler, in the bomb bay above the X-2, the system operation was being tested.

There was an explosion. The X-2 fell from the bomber and dropped into Lake Ontario, between Trenton, Ontario, Canada, and Rochester, New York, U.S.A. Skip Ziegler and an engineer aboard the bomber, Frank Wolko, were both lost. A technician, Robert F. Walters, who was in the aft section of the B-50 with Wolko, was badly burned and suffered an injured eye.

The B-50’s pilots, William J. Leyshon and David Howe, made an emergency landing at the Bell Aircraft Corporation factory airport at Wheatfield, New York (now, the Niagara Falls International Airport, IAG). The bomber was so heavily damaged that it never flew again.

Heavy fog over the lake hampered search efforts. Neither the bodies of Ziegler and Wolko or the wreckage of the X-2 were ever found.

A Bell X-2 rocketplane is loaded aboard the Boeing B-50A Superfortress "mothership," 46-011. (U.S. Air Force)
A Bell X-2 rocketplane is loaded aboard the Boeing B-50A-5-BO Superfortress “mothership,” 46-011. (U.S. Air Force)

After a series of explosions of early rocketplanes, the X-1A, X-1-3, X-1D and the X-2,  investigators discovered that leather gaskets which were used in the fuel system had been treated with tricresyl phosphate (TCP). When this was exposed to liquid oxygen an explosion could result. The leather gaskets were removed from the other rocketplanes and the explosions stopped.

The X-2 was a joint project of the U.S. Air Force and NACA (the National Advisory Committee on Aeronautics, the predecessor of NASA). The rocketplane was designed and built by Bell Aircraft Corporation of Buffalo, New York, to explore supersonic flight at speeds beyond the capabilities of the earlier Bell X-1 and Douglas D-558-II Skyrocket. Two X-2s were built.

In addition to the aerodynamic effects of speeds in the Mach 2.0–Mach 3.0 range, engineers knew that the high temperatures created by aerodynamic friction would be a problem, so the aircraft was built from stainless steel and K-Monel, a copper-nickel alloy.

The Bell Aircraft Corporation X-2 was 37 feet, 10 inches (11.532 meters) long with a wingspan of 32 feet, 3 inches (9.830 meters) and height of 11 feet, 10 inches (3.607 meters). Its empty weight was 12,375 pounds (5,613 kilograms) and loaded weight was 24,910 pounds (11,299 kilograms).

The X-2 was powered by a throttleable two-chamber Curtiss-Wright XLR25-CW-1 rocket engine that produced 2,500–15,000 pounds of thrust (11.12–66.72 kilonewtons)

Boeing EB-50D Superfortress 48-096 with a Bell X-2 (U.S. Air Force)

Rather than use its limited fuel capacity to take off and climb to altitude, the X-2 was dropped from a modified heavy bomber as had been the earlier rocketplanes.

The launch altitude was 30,000 feet (9,144 meters). After the fuel was exhausted, the X-2 glided to a touchdown on Rogers Dry Lake at Edwards Air Force Base.

The X-2 reached a maximum speed of Mach 3.196 (2,094 miles per hour/3,370 kilometers per hour) and maximum altitude of 126,200 feet (38,466 meters).

Bell X-2 46-675 on its transportation dolly at Edwards Air Force Base, California, 1952. (NASA)
Bell X-2 46-675 on its transportation dolly at Edwards Air Force Base, California, 1952. (NASA)

Jean LeRoy Ziegler was born 1 January 1920 at Endeavor, Pennsylvania. He was the first of three sons of LeRoy Curtiss (“Lee”) Ziegler, a stationary engineer for a gas field, and Daisy Pearl Gesin Zeigler.

Ziegler attended Endeavor High School, and then studied at Pennsylvania State College for two years.

Jean LeRoy Ziegler, circa 1940. (Niagara Aerospace Museum)

During the last week of June 1940, Ziegler enlisted in the United States Army Air Corps. He was sent to the Alabama Institute of Aeronautics at Tuscaloosa, Alabama, for Phase 1 primary flight training. He then went on to advanced training at Maxwell Army Air Field, near Montgomery, Alabama. Upon graduation, Ziegler was commissioned as a second lieutenant, 7 February 1941.

Lieutenant Ziegler was assigned to Patterson Field, Fairfield, Ohio, as at transport pilot.

In September 1941, Lieutenant Ziegler, a reserve officer, was released from active duty. He was then employed by Pan American Airways-Africa, Limited. On 26 September 1941, he departed Ohio for New York, and from there traveled to Africa for a six-month assignment.

Pan American Airways-Africa, Limited, routes

Ziegler flew the Douglas DC-3 for Pan Am in Africa and the Middle East, India, Burma and China. He is credited with being one of the first three pilots to fly cargo from Burma to China over the Himalaya Mountains, a route that would be know as “The Hump.” He flew ammunition and fuel to the American Volunteer Group (better known as the “Flying Tigers”) in China, and returned with Chinese refugees.

On 10 June 1942, Ziegler returned to the United States, arriving in Miami, Florida, via Port of Spain, Trinidad, aboard a Pan American Airways Boeing 314A, NC18612, Cape Town Clipper. (This was the last Model 314 built by Boeing.)

Boeing 314A NC18612, Clipper Cape Town. (David J. Gauthier Collection, 1000aircraftphotos.com)

After a few months, Ziegler was hired by the Curtiss-Wright Corporation, Airplane Division, as a production test pilot. He was assigned to Plant 2 at Cheektowaga, New York. He would fly the P-40 Warhawk and SB2C Helldiver.

Curtiss Gets Another New Test Aviator

Military Supply Pilot Joins Buffalo Staff

    Jean L. Ziegler of Endeavor, Pa., who flew hundreds of refugees into India when the Japs swarmed through Burma last year, has been added to the production test pilot staff of the Curtiss-Wright Corporation Airplane Division in Buffalo.

     The 22-year-old flier is the second to join Curtiss here within a week. Donald Armstrong, 22, former flight lieutenant in the Royal Canadian Air Force, reported last week.

Graduate of Army School

     Ziegler entered the Army Flying School at Maxwell Field, Ala., in June 1940, and was graduated from the advanced course a year later. He was transferred to a transport unit at Patterson Field, O., where he remained until September, 1941. Then he was hired by Pan American Airways to serve as a pilot on military supply routes of the transport ferry command in Africa, India, the Middle East, China and Burma.

     When the Japs began an intensive drive toward the north in Burma, Ziegler was on of the airmen who volunteered to fly refugees into India. He carried fuel and ammunition to Burma units of the American Volunteer Group (Flying Tigers) and came out with plane loads of men women and children. The planes used were Douglas DC-3s.

     Ziegler was born in Franklin, Pa., and attended Pen State for two years before enrolling at Maxwell Field. He holds a second lieutenant’s commission in the Army Air Corps Reserve.

—Buffalo Courier Express, Vol. CVIII, No. 99, Tuesday 27 October 1942, Page 7 Column 1 and 2

On 22 December 1942, Ziegler registered for Selective Service (conscription). His draft card describes him as 6 feet, 1 inch (185 centimeters) tall, 170 pounds (77 kilograms), with brown hair, gray eyes, and a ruddy complexion.

Motor Trouble caused Test Pilot Jean L. Ziegler to crash land a Curtiss-Wright P-40 at the municipal airport Friday afternoon. He was unhurt. The plane was damaged slightly. Gasoline in an auxiliary tank ignited but firemen of Engine 27 quickly put out the flames.

—Buffalo Evening News, Vol CXXV, No. 93, Saturday, 30 January 1943, Page 3, Column 3

At 4:00 p.m., 13 March 1943, Jean LeRoy Ziegler married Miss Flora Mae Thompson at the Endeavor Presbyterian Church, in their hometown of Endeavor, Pennsylvania. The ceremony was officiated by Reverend Taylor. Miss Thompson was a fellow student at Endeavour High School. She was trained as a nurse at the Millard Fillmore Hospital in Buffalo, New York. At the time of their marriage, she had been employed there for one year. The couple would have three daughters, Sandra, Patricia, and Mary.

Skip Ziegler’s Curtiss-Wright XP-40Q-2A-CU, NX300B (ex-USAAF P-40K-1-CU 45-45722), circa September 1947. (Military Matters)

On 1 September 1947, Skip Ziegler was involved in an interesting incident at the National Air Races in Cleveland, Ohio. Flying his Curtiss-Wright XP-40Q-2A-CU Warhawk, NX300B, he had qualified in thirteenth place for the twelve airplane field in the Thompson Trophy Race. But a faster airplane, NACA test pilot Howard Clifton  “Tick” Lilly’s Bell P-63A-7-BE King Cobra, NX69901 (42-69063), flown by William Bour, which had qualified, was also in earlier race. With only ten minutes between the two races, starters thought that P-63 might not be ready in time for the start of the Thompson. They allowed Ziegler to take the seventh place in the starting lineup.

Bour did make it to the starting line in time, but officials failed to tell Ziegler to withdraw. The twelve-airplane race started with thirteen airplanes.

During the fourteenth lap of the twenty-lap race, Ziegler was in fourth place when the engine of his XP-40Q caught fire. He bailed out in front of the viewing grandstands and parachuted to the ground, suffering a broken leg. His airplane crashed and was destroyed. (This was the second crash during the race. Only six airplanes finished.) Cook Cleland won the Thompson Trophy with his #74 Goodyear F2G-2 Corsair, N5577N (Bu. No. 88463).

By 1949, Ziegler and his family had moved to Los Angeles, California, where he was employed as a test pilot for North American Aviation, Inc. On 26 September 1949, he took off from Vultee Field, Downey, California, on the first flight of the XT-28, 48-1371, the first of two prototype trainers for the U. S. Air Force. This would go into production as the T-28A Trojan.

XT-28 48-1471 landing at Edwards AFB 3 Feb 1950
The first of two prototype North American Aviation XT-28s, 48-1371, lands at Edwards Air Force Base, 3 February 1950. (U.S. Air Force)

On 1 October 1950, Ziegler became the chief test pilot for the Bell Aircraft Corporation. He was involved in testing Bell’s experimental aircraft at Edwards Air Force Base in California.

On 20 June 1951, he took the experimental variable-sweep Bell X-5, 50-1838, for its first flight. Ziegler would deploy the X-5’s variable sweep wings in flight for the first time on 27 July 1951.

The Bell X-5 had variable sweep wings. (U.S. Air Force 151021-F-DW547-002)

Three days earlier, 24 July 1951, Ziegler made the first glide flight in the new Bell X-1D, 48-1386. This was a second-generation supersonic rocketplane built of the Air Force. This research aircraft was instrumented for the investigation of aerodynamic heating. Its nose gear was damaged on landing. This would be the X-1D’s only successful free flight. On 22 August 1951, following an internal explosion, it was jettisoned from its EB-50A mother ship and destroyed on impact with the desert floor.

Bell X-1D 48-1386. (Bell Aircraft Corporation)

On 8 October 1951, Ziegler made the twentieth and final contractor’s flight of the X-5 before turning over to its Air Force test pilot, Major Frank Kendall (“Pete”) Everest.

On 27 June 1952, Ziegler made the first glide flight of the new, swept-wing Bell X-2 Mach 3 research rocketplane. The second X-2, 46-675, was the first of the two to fly.

Bell X-2 46-675 after nose gear collapsed on landing at Edward Air Force Base, California, 27 June 1952. Bell Aircraft Corporation test pilot Jean Leroy (“Skip”) Zielgler is still seated in the cockpit. (National Aeronautics and Space Administration, Armstrong Flight Research Center, E-749)

On 14 February 1953, the Bell X-1A, 48-1387, made its first first powered flight with Skip Ziegler in the cockpit. The X-1A, like the X-1D, was a second second generation version of the X-1 series. Originally ordered by the Air Force, it had been taken over by the National Advisory Committee for Aeronautics (NACA). Delays caused by a redesign of the fuel system and lack of funding resulted in it being competed three years behind schedule.

Bell X-1A 46-1384 (U.S. Air Force)

Ziegler demonstrated the successful operation of the X-1A with all four chambers of its Reaction Motors XLR-11-RM-5 rocket engine on 26 March 1953. During a flight on 10 April 1953, Ziegler encountered a low-frequency vibration in its elevators, limiting the rocketplane to 0.93 Mach. During another flight on 25 April 1953, the X-1A’s fuel system turbopump oversped. Ziegler shut down the rocket engine and jettisoned the remaining fuel before gliding to a landing.

As described above, Jean LeRoy Ziegler was killed on 13 May 1953 as a result of an internal explosion of the second Bell X-2. His body was never recovered.

© 2025, Bryan R. Swopes