Curtis XP-55 interceptor
Developed to meet a 1939 USAAC specification for an fighter, the XP-55 was an unconventional design. It was a swept wing canard pusher aircraft that lacked a tail. Only three prototypes were produced, with the first taking flight in July 1943. Testing continued through 1944, but due to inherent stability problems and poor low-speed handling characteristics the type was abandoned.