The Grumman F4F Wildcat developed as a response to a US Navy design competition launched in 1936 to find a new carrier based fighter aircraft.
Grumman had a track record of producing biplane fighters for the US Navy, and their response to the 1936 contest was another biplane. The main competition came from the Brewster XF2A-1, a monoplane. The US Navy placed orders for a prototype of both aircraft – monoplane technology was still not entirely trusted, so the Grumman design could be seen as a backup.
The XF4F-1 was to be a biplane, powered by an 800 hp engine, and in many ways similar to the existing Grumman F3F-3. The prototype was never completed after it became clear that the new design was not much better than the older aircraft. In July 1936 Grumman switched their efforts to the XF4F-2, a monoplane design.
Work on the XF4F-2 prototype began in July 1936. The aircraft first flew on 2 September 1937. It was a mid-wing all-metal aircraft, powered by the 1,050 hp Pratt & Whitney R-1830-66 Twin Wasp engine. In tests it reached a maximum speed of 290 mph, faster than the Brewster prototype could then manage, but it suffered a series of failures during testing. Despite being ten mph faster than the Brewster aircraft, it was otherwise inferior, and in June 1938 the contract for the Navy’s first monoplane fighter went to the Brewster aircraft.
The XF4F-2 had suffered a serious accident on 11 April 1938. Even so, and despite not giving it the production contract, the Navy was willing to support further work on the XF4F. From October 1938 Grumman worked to improve the performance of their fighter. A more powerful engine (the Pratt & Whitney R-1830-76, giving 1200 hp) was used. The aircraft was made 19 inches longer. The wingspan was increased by four feet to 38 feet. Squared wing tips were adopted. This third F4F design had much better performance, capable of reaching a top speed of 335 mph 21,300 feet along with good handling and manoeuvrability.
The French were the first to order the new aircraft, placing a order for 81 aircraft in March 1939. On 8 August 1939 the US Navy finally placed an order for 54 F4F-3s. Eventually 7,816 F4Fs (and variants) were produced, a good return for Grumman’s persistence.
This prototype was built to test out the Wright R-1820-40 Cyclone nine-cylinder air cooled radial engine, after problems developed with the R-1830 engine’s two-stage supercharger. Two prototypes were built, with the first flying in June 1940, and achieved a top speed of 306 mph, but the single stage supercharger resulted in poor high altitude performance. The dash five did not enter production. Later the two prototype aircraft were adapted to test other engines, including the Wright R-1820-54 turbo-charged engine, which produced a top speed of 340 mph.