What are the most weird-looking airplanes that ever flew?
Is it a helicopter or an airplane? The Sikorsky Aircraft Corporation created this monstrosity for NASA. The aircraft is described as a four-bladed rotor system added to an X-wing designed aircraft.The aircraft was designed to be a concept that integrated helicopter hovering with winged aircraft high speeds, and it also featured vertical takeoff. The prototype was built in 1986 but it never flew, and two years later it was canceled.