Boeing 273 / XF7B-1
Designed to meet the requirements of a US Navy specification issued on 6 December 1932, the XF7B-1 (Model 273) was the first all-metal cantilever low-wing monoplane single-seat fighter with a retractable undercarriage, and powered by a Pratt & Whitney SR-1340-30 engine rated at 550hp at 3050m.
The XF7B-1 featured a fully-enclosed cockpit and was flown for the first time on 14 September 1933. Armament comprised two 7.62mm machine guns. After initial evaluation, the XF7B-1 was returned to its manufacturer to have split flaps and a longer-chord engine cowling fitted. Subsequently the enclosed cockpit gave place to an open cockpit. The US Navy considered that the XF7B-1 offered inadequate view and too high a landing speed for shipboard operation, and the sole prototype was scrapped after, in March 1935, the fighter was inadvertently stressed to 12.1g (although the designed load factor was only 9.0) when the pilot pulled out of a 668km/h dive too abruptly following collapse of the windscreen.
Engine: Pratt & Whitney SR-1340-30, 550hp at 3050m
Take-off weight: 1656 kg / 3651 lb
Empty weight: 1262 kg / 2782 lb
Wingspan: 9.73 m / 31 ft 11 in
Length: 8.41 m / 27 ft 7 in
Height: 2.26 m / 7 ft 5 in
Wing area: 19.79 sq.m / 213.02 sq ft
Max. speed: 375 km/h / 233 mph
Range: 1207 km / 750 miles