X-31 January 19, 1995

3261 Aerial image of the crash site. CLUI photo

The X-31 was an experimental thrust-vectoring jet designed for stable flight at high angles of attack. The first of only two X-31 airframes built crashed on what was supposed to the plane’s final test flight. After 43 minutes of tests, German research pilot Karl-Heinz Lang was headed back to base when a frozen pitot tube provided erroneous information to the flight computers, causing the plane go out of control. The pilot ejected and landed safely, but with back injuries. The plane hit the ground less than a half mile from houses and Highway 58, and burst into flames.

3262 NASA photoThe X-31 was built to study advanced maneuvering capabilities for future fighter aircraft. The engine thrust could be directed using paddles over the jet’s exhaust, which allowed the plane to perform many unusual and un-aerodynamic maneuvers, such as flying diagonally, and even flying in place, pointing upwards. Two were made in 1990, and over 500 test flights were performed on them until the end of the program in 1995. The international project was managed by the Advanced Research Projects Agency (ARPA), and included participation by NASA, the U.S. Navy, U. S. Air Force, Rockwell Aerospace, the Federal Republic of Germany and Daimler-Benz. The only surviving X-31 is on display in Germany. 

Tracking cameras at Edwards Air Force Base follow the Rockwell X-31 on its final test flight on January 19, 1995, as it unexpectedly goes out of control and crashes. The pilot, seen ejecting from the plane, landed safely, by parachute. The plane exploded on impact, less than half a mile from a house, next to US Highway 58, west of Boron, California.  Video courtesy of Peter Merlin/NASA.

A camera in the cockpit captures the movement and guages of the out-of-control plane, and the radio communications between the pilot and flight controllers, moments before ejection and loss of control.  Video courtesy of Peter Merlin/NASA.

A computer model constructed to study the crash.  Video courtesy of Peter Merlin/NASA.

Tracking cameras at Edwards show the plane as it became unstable, and the pilot ejecting, followed by pilotless uncontrolled flight as the plane falls through the air and crashes to the ground.  Video courtesy of Peter Merlin/NASA.