Republic built two prototype XF-91s -- the museum’s aircraft was the first one built, and it first flew in May 1949. The Museum’s XF-91, the only remaining example, was transferred from Edwards AFB, California, in 1955.
Republic XF-91
Thunderceptor
Originally conceived in the mid-1940s as an interceptor, the XF-91 was America’s first rocket-powered fighter to fly faster than the speed of sound. Its rocket engine supplemented its main turbojet engine, greatly increasing the aircraft’s speed and climb rate. With its afterburning turbojet and rocket engine in operation, the XF-91 possessed a remarkable climb rate of nearly 30,000 feet per minute.