• The X-31 provided information for proceeding with the designs of the next generation highly maneuverable fighters.

Three thrust vectoring paddles made of graphite epoxy and mounted on the X-31's aft fuselage were directed into the engine exhaust plume to provide control in pitch (up and down) and yaw (right and left) to improve maneuverability. The paddles sustained temperatures of up to 1,500 degrees centigrade for extended periods of time. In addition, the X-31s was configured with movable forward canards, wing control surfaces, and fixed aft strakes. The canards are small wing-like structures located just aft of the nose, set on a line parallel to the wing between the nose and the leading edge of the wing.

The X-31 flight test program was conducted by an international test organization (ITO) managed by the Advanced Research Projects Office (ARPA), known as the Defense Advanced Research Projects Office (DARPA) before March 1993. The ITO included the U.S. Navy and U.S. Air Force, Rockwell Aerospace, the Federal Republic of Germany, Daimler-Benz (formerly Messerschmitt-Bolkow-Blohm and Deutsche Aerospace), and NASA. Gary Trippensee was the ITO director and NASA Project Manager. Pilots came from participating organizations.

The X-31 program demonstrated the value of using thrust vectoring (directing engine exhaust flow) coupled with advanced flight control systems, to provide controlled flight to very high angles of attack. The result was a significant advantage over conventional fighters in a close-in combat situation.