The twin-turbojet X-3, the only one built, was designed to test features of an aircraft suitable for sustained flights at supersonic speeds and high altitudes. A secondary mission was to investigate the use of new materials such as titanium and to explore new construction techniques.
The X-3 made its first test flight at Edwards AFB, California on October 20, 1952 and flew supersonically in June 1953. Unlike the X-1, X-2, and X-15 which were released in mid-air from a "mother plane," the X-3 operated in a more conventional manner by taking off from the ground. Engine development difficulties forced the use of lower powered engines than originally planned, prohibiting the X-3 program from achieving its design potential. However, data gained from the X-3 program was of great benefit in the development of the F-104, X-15, SR-71 and other high performance aircraft.