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7th of September 1956

An altitude of 126.200 feet (38.470 meters) was reached on this day in aviation history. This altitude was reached by Captain I, C. Kincheloe in one of the only two Bell X-2 built.

Making him the first pilot to climb above 100.000 feet (30.500 meters)

Bell X-2 Number 1 (#674) in landing configuration with Skids and Nosewheel deployed.

The Bell X-2 "Startbuster" was the second in a series of X-planes developed in the mid-'40s of the 20th century. It was a rocket-powered swept-wing aircraft designed especially for research into problems encountered with supersonic flight and to extend the speed and altitude regime researched by the X-1. The development o the X-2 took a long time as aerodynamics, controls and materials all had to be adapted to the thermo-dynamic loads encountered during the planned high-speed flights. It had a (for the time) unique rocket engine, the XLR25, which was throttle controllable, as first demonstrated by the Me 163B "Komet" during World War II. It was a two-chamber continuously throttleable rocket engine, providing 2500 to 15.000 lbf of thrust at sea level.

With a target speed of close to Mach 3, stability and controllability of the aircraft at high supersonic speeds was one of the developers main difficulties to overcome. One of these was the "thermal barrier", the heating of the structure, caused by the aerodynamic friction at high speeds.

To make the aircraft more resistant to these high temperatures it was made of stainless steel and K-Monel (a copper-nickel alloy).

The X-2 would be carried a loft attached to the belly of a B-50 bomber. The first flight of the X-2 was an unpowered flight on the 27th of June 1952 piloted by Jean "Skip" Ziegler.. 11 months later, on the 12th of May 1953 Ziegler was killed when X-2 #2 (46-675) exploded during testing of the liquid oxygen system, also killing a crew member of the B-50 mothership, Frank Wolko. The wreckage of the X-2 fell into Lake Ontario and was never recovered. Work continued with X-2 #1 (46-674) and this aircraft made the first powered flight on the 18th of November 1955. On the last flight of Lt. Col Frank Everest, his ninth flight, in late July 1956 the aircraft reached a speed of Mach 2.87 (1900 mph - 3050 kph).

He reported marginal effective flight controls, further analysis and wind tunnel data forecasted severe control and stability issues when reaching Mach 3.0

Further testing continued until also X-2 #1 was lost when the pilot lost control during a flight above Mach 3. Although the pilot activated his escape capsule he was not able to exit the escape capsule and deploy his parachute, killing him when he impacted the desert floor. The pilot was probably disabled by the forces exerted on him. The aircraft its self spiralled down and came down on the desert floor, breaking in in three pieces.

Bringing the X-2 program to an early end.

Specifications of the X-2; General characteristics

  • Crew: 1

  • Length: 37 ft 10 in (11.53 m)

  • Wingspan: 32 ft 3 in (9.83 m)

  • Height: 11 ft 10 in (3.61 m)

  • Wing area: 260 sq ft (24 m2)

  • Empty weight: 12,375 lb (5,613 kg)

  • Max takeoff weight: 24,910 lb (11,299 kg)

  • Powerplant: 1 × Curtiss-Wright XLR25 liquid-fuelled rocket engine, 15,000 lbf (67 kN) thrust at sea level


  • Maximum speed: 2,094 mph (3,370 km/h, 1,820 kn)

  • Maximum speed: Mach 3.196

  • Service ceiling: 126,200 ft (38,500 m)

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