The XH-51A was a Lockheed Model 186helicopter produced for the US Army modified for research at higher speeds than the original Lockheed Model 186, by adding a Pratt and Whitney J60-P-2 turbojet mounted on the port side of the cabin and cantilever mid-set wings. The XH-51A first flew in 1964 and in 1965 achieved a speed of 438 kmh - a record for a rotorcraft. Research XH-51A
 
The Probert Encyclopaedia was designed, edited and programed by
Matt and Leela Probert