sentences:  Fitted with the more powerful 7,100shp YT40-A-6 the XFY-1 flew the first full flight from vertical take-off to horizontal flight and back to vertical flight for landing, of a fixed wing aircraft, in November 1954.Continuing concerns over propellers and the poor payload and performance precluded further development.Some flying was carried out with the Hiller X-18 but most research was carried out with the aircraft attached firmly to a force measuring platform, that could be raised hydraulically, to gather data on ground cushion effects.