The XP-55 came about as a result of the 1939 USAAC proposal R-40C, which called for a new high-performance fighter and spawned several other unusual designs, including the XP-54 Swoose Goose and the XP-56 Black Bullet. Curtiss-Wright's design originally used an experimental Pratt & Whitney X-1800 engine, but after development issues brought the project to a halt, it instead used a more conventional Allison V-1710. The first Ascender prototype made its maiden flight on 19 July 1943. Just two more would be built before the cancellation of the XP-55's development due the aircraft stalling a number of times. This trait caused the crash of the first prototype, which was lost during stall trials on 15th November 1943. The second prototype first flew on 9th January 1944, with the third following