The X-31 program tried to improve the manoeuvrability of fighter planes through thrust vectoring, which is performed by three thrust-deflecting "paddles" behind the engine controlled automatically by the digital flight control system. This permits tactical manoeuvres at a 70-degree angle of attack, far beyond the stall angle of conventional aircraft. In total more than 400 flying hours were logged between 1990-1995 and 2001-2003 at Edwards AFB, CA, and NAS Patuxent River. This second and last testbed is now on display at the Deutsches Museum - Flugwerft Schleissheim.