Grumman XP-50
 The Grumman XP-50 was a land-based development of the shipboard XF5F-1 Skyrocket fighter entered into a USAAC contest for a twin-engine heavy interceptor aircraft. The Army Air Corps placed an order for a prototype on 25 November 1939 designating it XP-50 but it lost the competition to the Lockheed XP-49.