The Bell XP-77 was a lightweight wooden fighter aircraft produced to solve a problem that never materialised. During 1941, as American military production increased, there was a rear fear that the syupply of the light metal alloys used in aircraft might run short. The Army Air Forces responded with an informal requirement for an aircraft weighing 4,000lb, powered by a 400hp engine, capable of 400mph and produced from non-strategic materials.
Bell responded with the Tri-4, named after the figures in the specification. On 16 May 1942 the USAAF ordered twenty five of these aircraft, to be powered by the Ranger XV-770-9 engine with a two-stage supercharger. Bell expected this aircraft to be capable of 410mph at 27,000 feet.
The XP-77 was eventually built around the Ranger SGV-770C-1B engine, which could provide 450hp, but had no super-charger. It was constructed out of plywood constructed from Sitka spruce, a material that would cause significant delays in development.
After disappointing wind-tunnel tests early in 1943 Bell suggested that the order be reduced from twenty-five to six aircraft. The need for the P-77 was also disappearing fast – the feared supply shortages had yet to appear, and the need for a short range interceptor diminished as the prospects of an attack on the United States disappeared. In May 1943 the army reduced the size of the order once again, this time to only two aircraft.
The first XP-77 made its maiden flight on 1 April 1944 at Niagara Falls, NY, with Jack Woolams at the controls, while the second aircraft made its maiden flight on 2 May 1944. Early tests were disappointing. The top speed of the XP-77 was only 330mph, 70mph slower that required. The aircraft was noisy, there was too much vibration, and the aircraft needed a very long take-off run. The first prototype had already been damaged when on 2 October 1944 the second aircraft was lost after going into an inverted spin during an Immelman turn. The pilot escaped, but the aircraft was destroyed. The project was officially cancelled on 2 December 1944. The remaining prototype survived for some time after the war, before eventually being scrapped by Purdue University, where it had been on fixed display.
Gross weight: 3,583lb
Range: 550 miles at 270mph
Span: 27ft 6in
Length: 22ft 10.5in
Armaments: two .50in machine guns firing through propeller hub or one 20mm cannon in same place
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