2001: British test pilot Simon Hargreaves flew the Lockheed Martin X-35B through an in-flight conversion from the conventional to the STOVL mode and back before accelerating to Mach 1.08. This was the first time one of the two JSF demonstrator types had made a conversion and flown supersonically on the same flight. The X-35B is the same airframe as the X-35A but was modified to house the lift-fan conversion kit-seen here with fan doors open and engine exhaust nozzle rotated downward. Today, the X-35B and the lift fan rests at the Udvar-Hazy Center in Chantilly, VA, as part of the National Air and Space Museum collection. (USMC and Lockheed image)
