The Bell X-2 was an experimental swept-wing rocket plane that was designed to explore the effects of flying at very high speeds above Mach 3, but both aircraft were lost before any significant work had been done.
Bell submitted a design for a swept wing rocket plane in October 1945, and on 14 December they were given a contract to produce two prototype aircraft, which were to be used for experiments at Mach 3.5 and attitude of 125,000ft, investigating compressibility and the problems caused by heat at those high speeds.
Bell gained some experience with swept wing aircraft in 1946, producing the Bell L-39 by fitting swept wings to two P-63 Kingcobras, but the new aircraft was a much more advanced design. The fuselage used new metal alloys, including K-Monel. The low mounted tapered wings were swept back at 40 degrees, and had a slight dihedral of 3 degrees. The horizontal tail surfaces were similar in shape, and were at the base of the vertical fin, but at the top of the fuselage.
The cockpit was placed in a jettisonable nose section for emergencies - the idea was that the nose would separate from the aircraft, a small parachute would stabilize it and the pilot would then open the hatch and use his own parachute to escape. Sadly this didn't work in practice. The two prototypes were powered by a Curtiss Wright XLR25-CW-1/3 two-chamber rocket, which could produce 15,000lb thrust for 175 seconds or 2,500lb thrust for 650 seconds.
The second prototype was completed first, rolling out on 11 November 1950. Static tests took eight months, before finally it took off for its first captive flight, under a Boeing EB-50A, in July 1951.
The first free unpowered flight took place on 27 June 1952, with Bell's test pilot Jean Ziegler at the controls. On this occasion the nose wheel collapsed during the landing, delaying the programme for two months. The second free glide took place on 10 October and the third on 12 October.
The first engine was finally really early in 1953. It was fitting to the second prototype, and used in capture flights in the spring of 1943. This prototype never made an independent powered flight. On 12 May 1953 the X-2 was damaged by an explosion, fell off the B-50 and was lost in Lake Ontario. Jean Ziegler and Frank Wolko were both killed in the explosion, which was eventually traced to a problem with the liquid oxygen tank gaskets.
By then the first prototype had been completed. It made its first unpowered flight on 15 August 1954, but this revealed instability problems that needed fixing. The second glide, on 8 March 1955, showed that they hadn’t been improved, as the third, on 6 April. Bell eventually fixed the problem by installed a wider main skid, with a shorter oleo strut, to reduce the centre of gravity during landing.
The first powered flight of the first prototype took place on 18 November 1955 and the aircraft reached Mach 0.95. Over the next few flights the top speed slowly rose, reaching Mach 2.487 on 22 May 1956 and Mach 2.9806 on 23 July 1956.
The final flight of the X-2 came on 27 September 1956, with Captain Milburn Apt at the controls. He reached Mach 3.196 (2,094mph), an unofficial speed record, but Apt then lost control of the aircraft and had to jettison. The capsule separated, but Apt was unable to get out and was killed in the crash. This ended the X-2 programme.
Engine: Curtiss Wright XLR25-CW-1/3 two-chamber rocket
Span: 32ft 3in
Length: 37ft 10in
Height: 11ft 9in
Empty Weight: 12,375lb
Loaded Weight: 24,910lb
Maximum Speed: Mach 3.196./ 2,094mph