Quarter-scale model of a 41-ft -span X-wing aircraft developed by Lockheed from an idea conceived by Professor Ian Cheeseman of Britain. Lockheed have recently been awarded a U.S. Government contract to build and ground-test a full-scale 25-ft.-dia. X-wing machine. From take-off to about 230 m.p.h. the wing rotates: it is then locked as a fixed aerofoil for speeds up to approx. 600 m.p.h.