XP-55 airplane model. On July 13 1943, the first XP-55 (42-78845) was completed and had the same aerodynamic configuration as the final prototype CW-24B. The aircraft made its first test flight from the Army's Scott Field near the Curtiss-Wright plant in St. Louis on July 19, 1943. The pilot was J. Harvey Gray, Curtiss' test pilot. Initial testing revealed that the takeoff run was excessively long. To solve this problem the nose elevator area was increased and the aileron up trim was interconnected with the flaps so that it operated when the flaps were lowered.
The XP-55 Ascender was an unconventional design. It was developed to meet a 1939 USAAC specification for an interceptor fighter. It was a swept wing canard pusher aircraft that lacked a tail. In July 1943, only three prototypes were produced, with the first taking flight. Testing continued through 1944, but due to inherent stability problems and poor low-speed handling characteristics the type was abandoned.