Tag Archives: NACA

14 October 1938

The Curtiss-Wright XP-40 prototype, 38-10, on its first flight, 14 October 1938. Test pilot Ed Elliot is in the cockpit. (San Diego Air and Space Museum Archives) 16_008532

14 October 1938: At Buffalo, New York, test pilot Everett Edward Elliot made the first flight in the new Curtiss-Wright Corporation’s Model 75P, a prototype for a single-engine pursuit plane which had been designated XP-40 by the U.S. Army Air Corps.

Curtiss-Wright’s Chief Engineer, Donovan Reese Berlin, had taken the tenth production P-36A Hawk, Air Corps serial number 38-10, and had its air-cooled radial engine replaced with the Harold Caminez-designed, liquid-cooled, supercharged, 1,710.597-cubic-inch-displacement (28.032 liter) Allison Engineering Co. V-1710-C13 (V-1710-19).

Donovan Reese Berlin. (Niagara Aerospace Museum)

The V-1710-19 was a single overhead cam (SOHC) 60° V-12 engine with four valves per cylinder and a compression ration of 6.65:1. It had a Normal Power rating of 910 horsepower at 2,600 r.p.m. at Sea Level, and 1,060 horsepower at 2,950 r.p.m. for Takeoff. At 10,000 feet (3,048 meters), the V-1710-19 had Maximum Continuous Power rating of 1,000 horsepower at 2,600 r.p.m., and Military Power rating of 1,150 horsepower at 2,950 r.p.m. The engine required 100/130-octane aviation gasoline. It drove a three-bladed Curtiss Electric constant-speed propeller through a 2:1 gear reduction. The V-1710-19 was 8 feet, 1.75 inches (2.483 meters) long, 3 feet, 4.75 inches (1.035 meters) high and 2 feet, 4.94 inches (0.735 meters) wide. It weighed 1,320 pounds (599 kilograms).

Curtiss-Wright XP-40 38-10 (SDASM 16_008531)

At 1,829.39-cubic-inches (29.978 liters), the original Pratt & Whitney Twin Wasp S1C1-G (R-1830-17) 14-cylinder radial engine had greater displacement and produced 80 horsepower more for takeoff than the Allison V-12. The long, narrow V-12, though, allowed for a much more streamlined engine cowling for higher speed and greater efficiency.

XP-40 16_008533
Curtiss-Wright XP-40 prototype. (SDASM 16_008534)
The Curtiss XP-40 prototype at Langley Field in the original configuration. (NASA)
The Curtiss-Wright XP-40 in the original configuration at Langley Field. (NASA)
Everett Edward Elliot (1907–1981).

In the early testing, the XP-40 was much slower than expected, reaching only 315 miles per hour (507 kilometers per hour). (The P-36A Hawk had a maximum speed of  313 miles per hour). Engineers experimented with different placement for the coolant radiator, oil coolers and the engine air intake. The Air Corps project officer, Lieutenant Benjamin Scovill Kelsey, had the prototype sent to the National Advisory Committee for Aeronautics (NACA) Research Center at Langley Field, Virginia, where the full-size airplane was placed inside a wind tunnel.

Over a two-month period, NACA engineers made a number of improvements. The radiator was moved forward under the engine and the oil coolers utilized the same air scoop. The exhaust manifolds were improved as were the landing gear doors.

When they had finished, Lieutenant Kelsey flew the modified XP-40 back to Curtiss. Its speed had been increased to 354 miles per hour (570 kilometers per hour), a 12% improvement.

By December 1939 the airplane had been further improved and was capable of 366 miles per hour (589 kilometers per hour).

The Curtiss-Wright XP-40 prototype in a wind tunnel at Langley Field, 24 April 1939. (NASA)
Curtiss XP-40 in the NACA Full Scale Wind Tunnel at Langley Field, Virginia, April 1939. (NASA)
Curtiss-Wright XP-40 in the NACA Full Scale Wind Tunnel at Langley Field, Virginia, 24 April 1939. (NASA)

The Curtiss Hawk 75P, XP-40 38-10, was 31 feet, 1 inch (9.574 meters) long with a wingspan of 37 feet, 4 inches (11.354 meters) and overall height of 12 feet, 4 inches (3.734 meters). It had an empty weight of 5,417 pounds (2,457.1 kilograms) and maximum gross weight of 6,870 pounds (3,116.2 kilograms).

The prototype had a maximum speed of 342 miles per hour (550 kilometers per hour) at 12,200 feet (3,719 meters) with a gross weight of 6,260 pounds (2,839.5 kilograms). Its range was 460 miles (740 kilometers) flying at 299 miles per hour (481 kilometers per hour) with 100 gallons (378.5 liters) of fuel. With 159 gallons (601.9 liters) and with speed reduced to 200 miles per hour (322 kilometers per hour), the XP-40 had a maximum range of 1,180 miles (1,899 kilometers).

The prototype was armed with two air-cooled Browning AN-M2 .50-caliber machine guns mounted above the engine and synchronized to fire forward through the propeller arc.

The Air Corps placed an initial order for 524 P-40s. This was the largest single order for airplanes by the U.S. military up to that time. The first production model was the P-40 Warhawk, armed with two .50-caliber machine guns. There was only one P-40A variant which was a P-40 modified as a camera aircraft. The definitive pursuit model was the P-40B Warhawk, which retained the two .50-caliber guns of the P-40 and added two Browning M2 .30-caliber machine guns to each of the wings.

A Curtiss-Wright P-40B Warhawk, 79th Pursuit Squadron, 20th Pursuit Group, Hamilton Field, California, 1940. (U.S. Air Force)

The P-40B was best known as the airplane flown by the American Volunteer Group fighting for China against the Japanese. They were called the “Flying Tigers”. Between 1939 and 1945, Curtiss built 13,738 P-40s in many configurations. They flew in combat in every theater of operations during World War II.

A Curtiss-Wright Hawk 81-A3 (Tomahawk IIb) of the American Volunteer Group, Kunming, China, 1942. (U.S. Air Force)

© 2018, Bryan R. Swopes

8 October 1954

Captain Arthur W. Murray, U.S. Air Force (1918–2011). Murray is wearing a David Clark Co. T-1 capstan-type partial-pressure suit with K-1 helmet for high altitude flight. (U.S. Air Force)
Captain Arthur W. Murray, U.S. Air Force (1918–2011). Murray is wearing a David Clark Co. T-1 capstan-type partial-pressure suit. (U.S. Air Force)

8 October 1954: After two earlier glide flights flown by test pilot Jack Ridley, Captain Arthur Warren (“Kit”) Murray, U.S. Air Force, made the first powered flight of the Bell Aircraft Corporation X-1B rocket-powered supersonic research aircraft, serial number 48-1385.

Five months earlier, Murray had flown the X-1A to an altitude of 90,440 feet (25,570 meters). He was the first pilot to fly high enough to see the curvature of the Earth and a dark sky at mid day.

The X-1B was the third in a series of experimental X-1 rocketplane variants built by the Bell Aircraft Corporation for the United States Air Force and the National Advisory Committee for Aeronautics (NACA), for research into supersonic flight. It was fitted with 300 thermocouples to measure aerodynamic heating. It was the first aircraft equipped with a pilot-controlled reaction control system which allowed for maneuvering the aircraft at high altitudes where normal aerodynamic controls were no longer effective.

NACA 800, a modified Boeing B-29 Superfortress, 45-21800, with the Bell X-1B, at Edwards Air Force Base, 8 April 1958. (NASA)
NACA 800, a modified Boeing B-29 Superfortress, 45-21800, with the Bell X-1B, at Edwards Air Force Base, 9 April 1958. (NASA)

Like the X-1 and X-1A, the X-1B was carried by a modified four-engine B-29 Superfortress heavy bomber (B-29-96-BW 45-21800), before being airdropped at altitudes of 25,000 to 35,000 feet (7,620 to 10,668 meters) near Edwards Air Force Base, California. After its fuel was expended, the pilot would glide for a landing on Rogers Dry Lake.

The X-1B was 35 feet, 7 inches (10.846 meters) long with a wing span of 28 feet (8.53 meters). Its loaded weight was 16,590 pounds (7,520 kilograms). The X-1B was powered by a Reaction Motors XLR11-RM-6 four-chamber rocket engine, fueled with a mixture of water and alcohol with liquid oxygen. It produced 6,000 pounds of thrust (26.689 kilonewtons. The XLR11 was 5 feet, 0 inches (1.524 meters) long, 1 foot, 7 inches (0.483 meters) in diameter, and weighed 210 pounds (95 kilograms). Each of the four thrust chambers were 1 foot, 9¾ inches (0.552 meters) long and 6 inches (0.152 meters) in diameter.

The rocket plane was designed to reach 1,650 miles per hour (2,655 kilometers per hour) and 90,000 feet (27,432 meters).

Bell X-1B (Bell Aircraft Corporation)
Bell X-1B 46-1385 (U.S. Air Force)
Bell X-1B 46-1385 on Rogers Dry Lake (NASA E-2547)
Bell X-1B on Rogers Dry Lake (NASA)
Bell X-1B 46-1385 on Rogers Dry Lake (NASA)

This was Kit Murray’s only flight in the X-1B. After being flown by a number of other Air Force test pilots, including Stuart Childs and Frank Everest, the rocketplane was turned over to NACA for the continued flight test program. NACA research pilots John McKay and Neil Armstrong made those flights.

X-1B 48-1385 made 27 flights. It was retired in January 1958. It is in the collection of the National Museum of the United States Air Force at Wright-Patterson Air Force Base, Ohio.

Bell X-1B 46-1385 parked on Rogers Dry Lake, 30 July 1958. (NASA)
Bell X-1B 46-1385 parked on Rogers Dry Lake, 30 July 1958. (NASA)
Bell X-1B 46-1385 parked on Rogers Dry Lake, 30 July 1958. (NASA)
Bell X-1B 46-1385 parked on Rogers Dry Lake, 30 July 1958. (NASA)

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.

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.

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.)

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.

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.

© 2018, Bryan R. Swopes

Albert Scott Crossfield, Jr. (2 October 1921–19 April 2006)

Albert Scott Crossfield, aeronautical engineer and test pilot, 1921–2006. (Jet Pilot Overseas)
Albert Scott Crossfield, Jr., Aeronautical Engineer and Test Pilot, 1921–2006. (Jet Pilot Overseas)

Albert Scott Crossfield, Jr., was born at Berkeley, California, 2 October 1921, the second of three children of Albert Scott Crossfield and Lucia Dwyer Scott Crossfield. (“Scott Crossfield” is the family name, going back for many generations.) His father was a chemist who was the superintendent of the Union Oil Refinery in Wilmington, California. At the age of 5 years, the younger Scott Crossfield contracted pneumonia. He was comatose for a time and not expected to survive. When he finally began to recover, he was confined to bed for many months. The effects of this illness lasted throughout his childhood.

It was during this time that he developed his interest in aviation. He learned to draw, studied airplanes, and built scale models. Charles F. (“Carl”) Lienesch, who was a pilot for the Union Oil Company, gave Scotty his first ride aboard an airplane at age 6. As a teenager, he took flight lessons in an Inland Sportster at the Wilmington Airport.

Inland R400 Sportster NC267N, circa 1939. (William T. Larkins)

After his family bought a farm in Oregon, Scott Crossfield continued flight lessons and soloed a Curtis Robin at the age of 15. He earned his private pilot certificate at 18. After graduating from high school, “Scotty” helped his father with the family farm before attending the University of Washington as a student of aeronautical engineering. He took a job at Boeing to pay his tuition and support.

Ensign A. S. Crossfield, Jr.

After America’s entry into World War II, Scott Crossfield enlisted in the U.S. Army Air Corps as an aviation cadet, but because of expected delays in training, quickly transferred to the U.S. Navy. He enlisted as a Seaman 2/c in the Navy’s V-5 Program at the Naval Reserve Aviation Base, Seattle, Washington, on 21 February 1942. He began Primary Flight Training there, 7 May 1942. Scotty completed military flight training and was commissioned an Ensign, United States Navy, in December 1942.

On 21 April 1943, Ensign Albert Scott Crossfield, U.S. Navy, married Miss Alice Virginia Knoph at Corpus Christi, Texas.

Promoted to lieutenant (junior grade) with date of precedence 21 March 1944.

During World War II, Scott Crossfield served as a fighter pilot, flight and gunnery instructor, flying the Chance Vought F4U Corsair and Grumman F6F Hellcat. Though he was assigned to Fighting Squadron FIFTY-ONE (VF-51) aboard the Independence-class light aircraft carrier USS Langley (CVL-27), he did not serve in combat. He was promoted to the rank of lieutenant 1 August 1945. Scotty was released from active duty 31 December 1945. After the war he joined a Naval Reserve squadron and flew the Goodyear Aircraft Co. FG-1D Corsair at NAS Sand Point, Washington.

A Goodyear FG-1D Corsair, Bu. No. 92150, unfolding its wings at NAS Sand Point, circa late 1940s. The orange band around the fuselage shows that this airplane is assigned to a Naval Reserve squadron. (U.S. Navy)

During this time he resumed his education at the University of Washington and graduated with a bachelor’s degree in aeronautical engineering in 1949, and a master’s degree in 1950. As a graduate student he was the operator of the university’s Kirsten Aeronautical Laboratory wind tunnel.

The NACA High Speed Flight Station, 24 August 1954. The Boeing P2B-1S Superfortress is parked at the northeast corner of the ramp. (NASA)

In 1950 Scott Crossfield joined the National Advisory Committee for Aeronautics (NACA, the predecessor of NASA) as an Aeronautical Research Pilot at the NACA High Speed Flight Station, Edwards Air Force Base, California. He flew many high-performance jet aircraft like the North American Aviation F-100 Super Sabre, and experimental airplanes such as the Convair XF-92, Douglas X-3, Bell X-4 and X-5. He also flew the research rocket planes, making 10 rocket flights in the Bell X-1 and 77 in the Douglas D-558-II Skyrocket.

Douglas D-558-2 Bu. No. 37974 dropped from Boeing P2B-S1 Superfortress 84029, 1 January 1956. (NASA)
Douglas D-558-2 Skyrocket, Bu. No. 37974, is dropped from Boeing P2B-S1 Superfortress, Bu. No. 84029, 1 January 1956. (NASA)

On 20 November 1953, Scott Crossfield became the first pilot to fly faster than twice the speed of sound (Mach 2). The D-558-II was carried aloft by a Boeing P2B-1S Superfortress drop ship (a four-engine B-29 long range heavy bomber which had been transferred from the U.S. Air Force to the Navy, then heavily modified by Douglas) to 32,000 feet (9,754 meters) and then released. Scotty fired the LR8 rocket engine and climbed to 72,000 feet (21,945 meters). He put the Skyrocket into a shallow dive and, still accelerating, passed Mach 2 at 62,000 feet (18,898 meters). After the rocket engine’s fuel was expended, he flew the rocketplane to a glide landing on Rogers Dry Lake.

In 1955 Crossfield left NACA and joined North American Aviation, Inc., as Chief Engineering Test Pilot. He planned and participated in the design and operation of the X-15 hypersonic research rocketplane for the Air Force and NASA. He also worked closely with the David Clark Co., in the development of the project’s full-pressure suits.

Scott Crossfield testing an experimental David Clark Co. XMC-2 full-pressure suit in a thermal chamber at Wright Field. (Ralph Morse, LIFE Magazine/National Archives College Park Collection)

Milton O. Thompson, another X-15 test pilot, wrote in At the Edge of Space,

“. . . he was intimately involved in the design of the aircraft and contributed immensely to the success of the design, as a result of his extensive rocket airplane experience. . . Scott was responsible for a number of other excellent operational and safety features built into the aircraft. Thus, one might give Scott credit for much of the success of the flight program. . . .”

At the Edge of Space, by Milton O. Thompson, Smithsonian Institution Press, Washington and New York, 1992, at Page 3

Scott Crossfield, NAA Chief Engineering Test Pilot; Edmond Ross Cokeley, NAA Director of Flight Test;  and Charles H. Feltz, NAA Chief Engineer, with an X-15 hypersonic research rocketplane. (North American Aviation via Jet Pilot Overseas)

In 1959–1960, Scott Crossfield flew all of the contractor’s demonstration phase flights for the X-15, including 16 captive carry flights under the wing of the NB-52A Stratofortress while systems were tested and evaluated, one glide flight, and thirteen powered flights. He reached a a maximum altitude of 88,116 feet (26,858 meters) on Flight 6, and a maximum speed of Mach 2.97 (1,960 miles per hour/3,154 kilometers per hour) on Flight 26. The X-15 was then turned over to NASA and the Air Force. The X-15 Program involved a total of 199 flights from 1959 until 1968.

A. Scott Crossfield, wearing a David Clark Co. XMC-2 full-pressure suit, which he helped to design and test, with the first of three North American X-15s, 56-6670. (North American Aviation, Inc.)

After leaving the X-15 Program, Scott Crossfield continued as a Systems Director with North American Aviation, Inc., working on the Apollo Command and Service Module and the S-IVB second stage of the Saturn V rocket. He left North American in the late ’60s and served as an executive with Eastern Air Lines and Hawker Siddeley. He also continued as a aeronautical engineering consultant to private industry and government.

Among many other awards, Scott Crossfield was received the Harmon Trophy, the Collier Trophy, and the Iven C. Kincheloe Award of the Society of Experimental Test Pilots..

Scott Crossfield's 1962 Cessna 210A Centurion, photographed at Santa Monica Airport, California, 26 September 1999. (AirNikon Collection, Pima Air & Space Museum, Tucson, Arizona via airliners.net)
Scott Crossfield’s Cessna 210A Centurion, N6579X, photographed at Santa Monica Airport, California, 26 September 1999. (AirNikon Collection, Pima Air & Space Museum, Tucson, Arizona via airliners.net, used with permission)

In 1980 Crossfield resumed flying when he purchased a 1960 Cessna 210A Centurion, N6579X, serial number 21057579. This was a single-engine, four-place light airplane, powered by an air-cooled Continental six-cylinder engine. He had flown more than 2,000 hours in this airplane when it crashed during a severe thunderstorm, 19 April 2006, while on a flight from Prattville, Alabama, to Manassas, Virginia.

Albert Scott Crossfield, Jr., was killed. His remains are interred at the Arlington National Cemetery, Arlington, Virginia.

Albert Scott Crossfield, Jr., Test Pilot. (LIFE Magazine via Jet Pilot Overseas)

Highly recommended: Always Another Dawn: The Story Of A Rocket Test Pilot, by Albert Scott Crossfield and Clay Blair, Jr., The World Publishing Company, Cleveland and New York, 1960.

© 2018, Bryan R. Swopes

27 September 1956

Captain Milburn G. Apt, U.S. Air Force, with a Bell X-2. (U.S. Air Force)
Captain Milburn Grant Apt, United States Air Force, with a Bell X-2. (U. S. Air Force)

27 September 1956: Captain Milburn G. (“Mel”) Apt, United States Air Force, was an experimental test pilot assigned to the Air Force Flight Test Center at Edwards Air Force Base, California. After Frank Everest and Iven Kincheloe had made twelve powered flights in the Bell X-2 supersonic research aircraft, Mel Apt was the next test pilot to fly it.

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.

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).

Bell X-2 46-675 on its transportation dolly at Edwards Air Force Base, California, 1952. (NASA)
The second of two Bell X-2 supersonic research rocketplanes, 46-675, on its transportation dolly at Edwards Air Force Base, California, 1952. On 12 May 1953 this X-2 exploded during a captive test flight, killing Bell’s test pilot Jean L. “Skip” Ziegler. (NASA)

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)

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. A four-engine Boeing B-50D-95-BO Superfortress bomber, serial number 48-096, was modified as the drop ship and redesignated EB-50D.

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.

Bell X-2 46-674 after drop from Boeing EB-50D Superfortress 48-096. (U.S. Air Force)
Bell X-2 46-674 after drop from Boeing EB-50D Superfortress 48-096. (U.S. Air Force)

With Mel Apt in the cockpit on his first rocketplane flight, the B-50 carried the X-2 to 31,800 feet (9,693 meters). After it was dropped from the bomber, Apt ignited the rocket engine and began to accelerate. He passed Mach 1 at 44,000 feet (13,411 meters) and continued to climb. Apt flew an “extraordinarily precise profile” to reach 72,200 feet (22,007 meters) where he put the X-2 into a dive. The rocket engine burned 12.5 seconds longer than planned, and at 65,589 feet (19,992 meters) the X-2 reached Mach 3.196 (2,094 miles per hour, 3,377 kilometers per hour).

Milburn Apt was the first pilot to exceed Mach 3. He was The Fastest Man Alive.

Bell X-2 46-674 in flight over Southern California, 1955–56. Note the supersonic diamond-shaped shock waves in the rocket engine's exhaust. (Bell aircraft Corporation)
Bell X-2 46-674 in flight over Southern California, 1955–56. Note the supersonic diamond-shaped shock waves in the rocket engine’s exhaust. (Bell Aircraft Corporation)

It was known that the X-2 could be unstable in high speed maneuvers. The flight plan called for Apt to slow to Mach 2.4 before beginning a gradual turn back toward Rogers Dry Lake where he was to land, but he began the turn while still at Mach 3. Twenty seconds after engine burn out, the X-2 began to oscillate in all axes and departed controlled flight. His last radio transmission was, “There she goes.” ¹

Mel Apt was subjected to acceleration forces of ± 6 Gs. It is believed that he was momentarily unconscious. Out of control, the X-2 fell through 40,000 feet (12,192 meters) in an inverted spin. Apt initiated the escape capsule separation, in which the entire nose of the X-2 was released from the airframe. It pitched down violently and Mel Apt was knocked unconscious again. He regained consciousness a second time and tried to parachute from the escape capsule, but was still inside when it hit the desert floor at several hundred miles per hour. Mel Apt was killed instantly.

Since 1950, Milburn G. Apt was the thirteenth test pilot killed at Edwards Air Force Base.

Wreckage of the Bell X-2, 46-674. (U.S. Air Force)
Wreckage of the Bell X-2, 46-674, in the Kramer Hills, east of Edwards Air Force Base. (U.S. Air Force)
Wreckage of the Bell X-2, 46-674. (NASM 9A08208)

Milburn Grant Apt was born at Buffalo, Kansas, 8 April 1924. He was the third child of Oley Glen Apt, a farmer, and Ada Willoughby Apt.

“Mel” Apt enlisted as a private in the Air Corps Enlisted Reserve, United States Army, 9 November 1942. On 23 June 1943, Private Apt was appointed an Aviation Cadet. After completing flight training, Cadet Apt was commissioned a Second Lieutenant, Army of the United States (A.U.S.). He was promoted to First Lieutenant, A.U.S., 4 September 1945. Apt was released from active duty on 11 August 1946. On 10 October 1947, he was reclassified as a Second Lieutenant, Air Corps, United States Army, with date of rank 8 April 1945.

In February 1950, Lieutenant Apt, then stationed at Williams Air Force Base, Arizona, married Miss Faye Lorrie Baker of Phoenix. They would have two children.

Mel Apt earned a Bachelor of Science degree from the University of Kansas, Lawrence, Kansas, in 1951, and a second bachelor’s degree in aeronautical engineering from the Air Force Institute of Technology, Wright-Patterson Air Force Base, Ohio. He then attended the U.S. Air Force Experimental Test Pilot School at Edwards Air Force Base, California, graduating in September 1954. Apt was assigned to the Fighter Operations Branch, Air Force Flight Test Center, as a test pilot.

On 22 December 1954, Captain Apt was flying a chase plane during a test at Edwards. The test aircraft crash-landed on the dry lake and caught fire with its pilot trapped inside. Mel Apt, with his bare hands, rescued the other test pilot, saving his life. For this courageous act, he was awarded the Soldier’s Medal.

Captain Apt was posthumously awarded the Distinguished Flying Cross for his flight in the X-2. The medal was presented to his widow in a ceremony at Edwards in March 1957.

Captain Milburn Grant Apt, United States Air Force, was 32 years old at the time of his death. His remains were buried at the Buffalo Cemetery, Buffalo, Kansas.

Captain Iven Carl Kincheloe and Captain Milburn Grant Apt (seated in cockpit) with the Bell X-2 at Edwards Air Force Base, 1956. (Jet Pilot Overseas)

¹ Recommended: Coupling Dynamics in Aircraft: A Historical Perspective, by Richard E. Day, Dryden Flight Research Center, Edwards AFB, California NASA Special Publications 532, 1997.

© 2018, Bryan R. Swopes

23 September 1943

North American P-51B Mustang in teh full-scale NACA wind tunnel, Langley, Virginia, 23 September 1945. (NASA)
North American Aviation P-51B Mustang fighter in the Full-Scale Tunnel, NACA Langley Memorial Aeronautical Laboratory, Hampton, Virginia, 23 September 1943. (NASA)
Drag test of North American Aviation P-51B-1-NA Mustang 43-12105 in the NACA Full-Scale Tunnel. (NASA)