The first F-107 would fly in September 1956, breaking the sound barrier on its first flight. By the end of the year, the F-107 had pushed it beyond Mach 2, and weapons tests had commenced. Testing went well, so Tactical Air Command decided to have it fly off against the F-105, which was built to the same requirements with the same engine. The results were close - the F-107 offered better performance, particularly in climb rate and flight ceiling, but the F-105 had a better payload and thrust-to-weight ratio. Unfortunately for North American, TAC went with the F-105, which by then had already been ordered into production. With only three of the ordered nine prototypes completed, the order was cut and the program terminated. The first and third prototypes were given to NACA for high-speed testing, but the second prototype - devoid of vital instruments like navigation radios and cockpit lights - was unfit for further service and instead was flown off to the National Museum of the United States Air Force, where it remains to this day.