The first flight of the F-107 was on September 10, 1956. The F-107's competitor for the Air Force contract was the Republic F-105. While both aircraft performed very well the decision eventually came down on the side of the F-105 primarily because it had a full internal bomb bay while the F-107 did not. After Air Force testing ended two of the F-107 prototypes were turned over to NASA for experimental testing of the control system for the X-15 and high speed research flights.
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