Captain Michael N. Antoniou with YUH-1D 60-6029. (FAI)
27 September 1964: Captain Michael N. Antoniou flew the number two Bell YUH-1D-BF Iroquois, 60-6029, Bell Helicopter serial number 702, from Edwards Air Force Base in the high desert of southern California, non-stop to Rogers, Arkansas. The distance flown was 2,170.70 kilometers (1,348.81 miles), and established a Fédération Aéronautique Internationale (FAI) World Record for Distance Without Landing.¹
Captain Antoniou was a project test pilot assigned to the U.S. Army Aviation Test Activity at Edwards.
60-6029 was modified by Bell to reduce aerodynamic drag and weight. The windshield wipers, door handles, main rotor stabilizer bar and associated dampers, tail rotor drive shaft cover and 42° gear box cover had been removed. Gaps at the doors, crew steps, tail boom cargo compartment, etc., were sealed with tape.
Bell YUH-1D Iroquois 60-6029. (FAI)
The Bell Helicopter Co. UH-1D Iroquois (Model 205) was an improved variant the UH-1B (Model 204). The type’s initial military designation was HU-1, and this resulted in the helicopter being universally known as the “Huey.” The UH-1D has a larger passenger cabin, longer tail boom and increased main rotor diameter.
The UH-1D was a single main rotor/tail rotor medium helicopter powered by a turboshaft engine. It could be flown by a single pilot, but was commonly flown by two pilots in military service. The helicopter had an overall length of 57 feet, 0.67 inches (17.375 meters) with rotors turning. The fuselage was 41 feet, 5 inches (12.624 meters) long. The helicopter had a height of 13 feet, 7.4 inches (4.150 meters), measured to the top of the mast. The maximum gross weight of the UH-1D was 9,500 pounds (4,309.1 kilograms).
The two blade semi-rigid, under-slung main rotor had a diameter of 48 feet, 3.2 inches (14.712 meters), and turned counter clockwise when viewed from above. (The advancing blade is on the helicopter’s right.) At 100% NR, the main rotor turned 324 r.p.m. The two blade tail rotor assembly had a diameter of 8 feet, 6 inches (2.591 meters). It was on the left side of the pylon in a pusher configuration and turned counter-clockwise as seen from the helicopter’s left. (The advancing blade is above the axis of rotation.)
The YUH-1D was powered by a Lycoming T53-L-9 or -11 turboshaft engine which was rated at 1,100 shaft horsepower at 6,610 r.p.m., for takeoff (5 minute limit). The T53-L-11 was a two-shaft free turbine with a 6-stage compressor (5 axial-flow stages, 1 centrifugal-flow stage) and a 2-stage axial-flow turbine (1 high-pressure stage, and 1 low-pressure power turbine stage). As installed in the UH-1, the engine produced 115 pounds of jet thrust (511.55 Newtons) at Military Power.
Its maximum speed, VNE, was 124 knots (143 miles per hour, 230 kilometers per hour). With full fuel, 206.5 gallons (781.7 liters), the helicopter had a maximum endurance of three hours.
60-6029 was later modified to the prototype YUH-1H.
Captain Michael N. Antoniou with Bell YUH-1D-BF 60-6029 (c/n 702), circa 1965. (David Hatcher Collection)
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).
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)
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)
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, 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.
27 September 1946: Geoffrey Raoul de Havilland, Jr., O.B.E., Chief Test Pilot of the de Havilland Aircraft Co., Ltd., and the son of the firm’s founder, was killed during a test flight of a prototype DH.108 Swallow, TG306.
Geoffrey de Havilland, Jr., in the cockpit of the second DH.108 Swallow prototype, TG306. (FLIGHT)
De Havilland had taken off from the company airfield at Hatfield at 5:26 p.m. for a planned 45 minute flight. Flying over the Thames Estuary, east of London, England, de Havilland put the swept-wing jet into a high-speed dive from 10,000 feet (3,048 meters). As it approached 5,000 feet (1,524 meters) at 0.88 Mach, (658 miles per hour, 1,060 kilometers per hour), the shock waves building up along the wings’ leading edges disrupted the air flow over the wings, causing them to stall. TG306 pitched violently downward. A NASA report called this “. . . an undamped violently divergent longitudinal pitching oscillation at Mach 0.875. . . .” The extreme aerodynamic loads cracked the main spar and both wings failed. The DH.108 crashed into Egypt Bay, Gravesend, Kent.
The wreck was located the following day. The body of Geoffrey de Havilland was found ten days later. He had suffered a broken neck and fractured skull as a result of his head striking the canopy during the violent oscillations of the aircraft.
(Grace’s Guide)
FLIGHT reported:
Geoffrey de Havilland was one of the outstanding test pilots in the country, and his work has played a vital part in the perfecting of such noteworthy types as the Mosquito, Hornet, Vampire and 108. His death is a serious blow not only to the company but to the country, for in the exploration of the unknown threshold of sonic flight, a combination of skill and cool courage are qualities demanding the utmost of test pilots. Geoffrey de Havilland had these qualities in a very high degree.
—FLIGHT and AIRCRAFT ENGINEER, No.1971, Vol. 1, Thursday, 3 October 1946, at page 364
De Havilland DH.108 TG306. (Unattributed)
The DH.108 was a single-seat, single-engine jet fighter prototype with swept wings and no conventional tail. It was similar in configuration to the Messerschmitt Me-163 rocket-powered interceptor. The first two prototypes, TG283 and TG306, were built using production English Electric DH.106 Vampire F.I fuselages. TG283 had a 43° sweep to the wings’ leading edge, while TG306 had a 45° sweep. The airplane was powered by a de Havilland Goblin 3 centrifugal-flow turbojet engine (a development of the Halford H.1) which produced 3,350 pounds of thrust (14.90 kilonewtons).
The first and third DH.108s also crashed. VW120 was destroyed on 15 February 1950 when it crashed after a dive. The left wing had separated and the pilot, Squadron Leader Stuart Muller-Rowland, also suffered a broken neck as a result of the airplane’s violent oscillations. On 1 May 1950, while conducting low-speed tests, TG283 went into an inverted spin. Squadron Leader George E.C. Genders, AFC, DFM, bailed out but his parachute did not open before he hit the ground and he was killed.
Geoffrey de Havilland, Jr., OBE, exits the cockpit of a DH.108 Swallow prototype. (Photograph courtesy of Neil Corbett, Test and Research Pilots, Flight Test Engineers)
Yves Rossy over the English Channel, 26 September 2008. (Times Online)
26 September 2008: Yves Rossy flew across the English Channel, 22 miles (35 kilometers) in 13 minutes, using his jet-powered wing. At 8,000 feet (2,440 meters) over Calais he jumped from an airplane and aimed for the cliffs of Dover. His only means of steering was by moving his head. After flying at speeds of 120 miles per hour (193 kilometers per hour), he parachuted to the ground at Dover.
“David Hempleman-Adams, left, with Saint John resident Jim Rogers on Sept. 26, 2003, just before the balloon launch.” (Kings County Record)
26 September 2003: At 2:38 a.m., Friday, David Kim Hempleman-Adams, O.B.E., lifted off from the athletic field of Sussex Elementary School, Sussex, New Brunswick, Canada, in his Rozière balloon on a four-day transatlantic flight. Hempleman-Adams was in an open 7 feet × 3 feet (2.1 × 0.9 meters) wicker basket.
Hempleman-Adam’s Cameron R-90 being prepared for takeoff on a previous transatlantic attempt, 27 June 2003, at Mount Pleasant, Pennsylvania. (AP Photo/Gene J. Puskar)
The balloon was built by Cameron Balloons, Ltd., Bristol, in 2000. It was a Cameron R-90, serial number 4751. The balloon was first registered 31 March 2000, as G-BYZX.
The R-90 is a Rozière balloon, which has separate chambers for helium and heated air. This allows the aeronaut to control the balloon’s buoyancy, but the hybrid type uses much less fuel than a hot-air balloon. The type is named after its inventor, Jean-François Pilâtre de Rozier. The Fédération Aéronautique Internationale places the Cameron R-90 in the free balloon sub-class AM-08, for mixed balloons with a volume of 2,200–3,000 cubic meters (77,692–105,944 cubic feet).
G-BYZX had a maximum takeoff weight of 2,654 kilograms (5,851 pounds).
Hempleman Adams had previously flown G-BYZX, then named Britannic Challenge, to the North Pole, on 3 June 2000. Following his transatlantic flight, he would use it to set a FAI World Record for Altitude of 12,557 meters (41,198 feet), 23 March 2004.
During the first day, Hempleman-Adams’ balloon gradually rose to an altitude of 8,000 feet (2,438 meters) as it drifted eastward. On the second day he was at 10,000 feet (3,048 meters), and on Day 3 he reached a peak of 14,000 feet (4,267 meters).
The weather was very cold, with rain and snow. Hempleman-Adams said that the average temperature during the flight was -12 °C. (10.4 °F.). Ice built up on the balloon’s envelope, increasing its weight. It became heavy enough that the balloon began to descend. Hempleman-Adams was unable to prevent the descent by using the propane burners to heat the air and increase buoyancy, and was forced to lighten the balloon by jettisoning six propane cylinders.
During the third day, the balloon was hit by the shock waves of a Concorde supersonic airliner as it passed overhead at 30,000 feet (9,144 meters). Hempleman-Adams felt a very abrupt, but fortunately, brief, descent as a result.
G-BYZX reached the southwestern tip of Ireland at 8:30 a.m., BST, on 29 September, completing the transatlantic phase of his flight. The balloon continued to drift eastward, and at 6 p.m. on 30 September, came to rest near Hambleton, Lancashire, England. The total duration of the flight was 83 hours, 14 minutes, 35 seconds.
Sir David Kim Hempleman-Adams, K.C.V.O., O.B.E., K.St.J., D.L., is an interesting guy. He is the first person to have completed the True Adventurer’s Grand Slam, by reaching the North and South Poles, the North and South Magnetic Poles, and to have climbed the highest mountains on each of the seven continents. The Fédération Aéronautique Internationale online database currently credits him with 49 world aviation records.
David Hempleman-Adams waves at the camera after landing in England, 30 September 2003.
