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The Ryan XV-5 Vertifan was a jet-powered V/STOL experimental aircraft in the 1960s. The U.S. Army commissioned the Ryan VZ-11RY (which was redesignated as the XV-5 in 1962) in 1961, along with the Lockheed VZ-10 Hummingbird (redesignated as the XV-4). ==Design== The XV-5 was powered by two 2,658 lbf (13 kN) thrust J85 turbojets, similar to those used in the F-5 Freedom Fighter. Lift-fans in the wings and a smaller fan in the nose, powered by engine exhaust gas, were used for VTOL. It may be contrasted to the future F-35 Lightning II which has one fan driven by a driveshaft, balanced by a rotating rear nozzle. The 62.5 inch diameter〔"VZ-11 VTOL Lift From Fans In The Wings" Flight International, 27 September 1962〕 lift fan in each wing had a hinged cover on the upper wing surface which was opened for VTOL. The 36 inch (0.9 m) nose fan provided adequate pitch control but produced adverse handlling characteristics.〔"Lift-Fan Aircraft-Lessons Learned The Pilot's Perspective" Ronald M. Gerdes, NASA Contractor Report 177620August 1993〕 The fans provided vertical lift of approximately , nearly three times the thrust of the engines as turbojets. A set of louvered vanes underneath each of the wing fans could vector the thrust fore and aft and provided yaw control. The engine power setting determined the lift from the fans. Fan RPM was determined by the output from the J85 engines and the load on the fan.〔 Roll control was by differential actuation of the wing-fan exit louvers. Aircraft performance was subsonic, with delta wings superficially similar to those on the A-4 Skyhawk. The Vertifan had an unusual intake position above the two-seat side-by-side seating cockpit, and a T-tail. The XV-5A was finished in Army green and the XV-5B was painted in white NASA colors. The fans did not generate as much thrust as was hoped, and the vertical-horizontal flight transition was difficult and abrupt. The XV-5 would be one of the last manned aircraft designed and built by Ryan, which mainly manufactured drones after the mid 1960s. The XV-5 was one of many dozens of aircraft which attempted to produce a successful vertical takeoff aircraft, but the lift fan system was heavy and occupied considerable internal volume. Only the Hawker Siddeley Harrier would still be operational by the turn of the 21st century, as would technology to make possible the use of a shaft-driven fan in the F-35. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Ryan XV-5 Vertifan」の詳細全文を読む スポンサード リンク
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