By the late 1940s, the United States Navy was interested in the mixed-power concept for its shipborne fighters.

Jet engines of that era had very slow throttle response, which presented a safety concern in the case of a missed approach on an aircraft carrier as the aircraft might not be able to throttle up quickly enough to keep flying after leaving the end of the deck.

This led to orders for a number of mixed-propulsion fighters, including the FR Fireball.

Powered by both a 2,100 hp (1,566 kW) Pratt & Whitney R-2800 Double Wasp propeller engine, and an Allis-Chalmers J36 turbojet, the aircraft was in theory the fastest fighter in the US Navy at that time.

When this was completed in April of the same year, the aircraft flew several mixed-power trials, however on 8 May, it crashed on a landing approach.