On display in the Research & Development Gallery at the National Museum of the U.S. Air Force. This was the world's first VSTOL tilt-rotor aircraft, powered by a single P&W R-985 Wasp. It was the result of a joint initiative in 1951 between the US Army and USAF. Two were built, and the first hover tests began in 1955. Take off to horizontal flight and back was achieved on 18 Dec 58. It never went into production, but paved the way later for the CV-22 Osprey. The first XV-3 was written off, and this is the only surviving example.