The Grumman XF5F Skyrocket was a prototype of a twin-engine shipboard fighter interceptor to which Grumman Aircraft Engineering Corporation applied the model number G-34. The U.S. Navy ordered one prototype airplane on 30 June 1938 with the designation XF5F-1. The aircraft possessed a unique appearance in that the forward part of the fuselage did not extend forward of the wing. Provisions were included in the prototype for two 23 mm (0.91 in) Madsen cannons.
The aircraft flew for the first time on 1 April 1940. Engine cooling problems arose in the initial flights, resulting in modification to the oil cooling ducts. Further modifications were made to the prototype including reduction in the height of the cockpit canopy, revising the armament installation to four 0.5 in (12.7 mm) machine guns in place of the cannon, redesign of the engine nacelles, adding spinners to the propellers, and extending the fuselage forward of the wing. These changes were completed on 15 July 1941. Additional changes were needed after further flight tests that were not completed until 15 January 1942. In the meantime, Grumman began work on a more advanced twin-engine shipboard fighter, the XF7F-1, and further testing with the XF5F-1 supported the development of the newer design. The prototype continued to be used in various tests, although plagued by various landing gear problems, until it was struck from the list of active aircraft after it made a belly landing on 11 December 1944.
