EDWARDS AIR FORCE BASE, Calif -- The X-Wing, a one-of-a-kind helicopter/fixed wing aircraft built by Rotor Systems Research, arrived at the National Aeronautic Space Administration's Dryden facility aboard a Super Guppy transport. The craft was designed to take off, hover, and land like a helicopter but cruise like a conventional aircraft.
The X-Wing was one of a number of concepts proposed to combine the hovering capabilities of the helicopter with the speed potential of fixed wing aircraft. It used a large-diameter four-bladed stiff rotor system that can be stopped in flight to become an “X” wing. It has the promise of breaking the trend of Verticle Take-Off and Landing aircraft where higher speed requires higher hovering disc loadings. Additionally it achieved fixed wing flight without the need for a separate wing, promising a lower weight empty fraction (empty weight/gross weight)over those concepts that need both a rotor system and a wing. Because of its low hovering disc loading plus the power to fly at high subsonic speeds, a two-engined X-wing aircraft could hover and fly a good portion of its flight envelope on only one engine.
The Aero Spacelines Super Guppy was a large, wide-bodied cargo aircraft that was used for hauling outsize cargo components. It was the successor to the Pregnant Guppy, the first of the Guppy aircraft produced by Aero Spacelines. Five were built in two variants, both of which were colloquially referred to as the "Super Guppy". The Super Guppy was "the only airplane in the world capable of carrying a complete S-IVB stage", the third stage of the Saturn V rocket. The Super Guppy performed this role several times during the Apollo program.