May 25, 2017 F-22 Flying Test Bed is tip of spear for Raptor mission systems From time to time, the F-22 Raptor Combined Test Force at the 411th Flight Test Squadron gets a visit from an old friend. A highly modified and instrumented Boeing 757 called the F-22 Flying Test Bed is an F-22 avionics laboratory. The experimental FTB is the very first Boeing 757 ever produced,