V-22 Osprey
The V-22 Osprey is a joint service, multimission, military tiltrotor aircraft with both a vertical takeoff and landing (VTOL) and short takeoff and landing capability (STOL)Built by Boeing Helicopters-Bell textron. It is designed to perform missions like a conventional helicopter with the long-range, high-speed cruise performance of a turboprop aircraft. The initial operators are the U.S. Marine Corps and United States Air Force. The FAA classifies the Osprey as a model of powered lift aircraft.The Osprey is the world’s first production tiltrotor aircraft, with one three-bladed proprotor, turboprop engine, and transmission nacelle mounted on each wingtip. It typically operates as a helicopter with the nacelles vertical (rotors horizontal) for takeoff and landing. Once airborne, the nacelles rotate forward 90° in as little as 12 seconds for horizontal flight, converting the V-22 to a more fuel-efficient, higher-speed turboprop airplane. STOL rolling-takeoff and landing capability is achieved by having the nacelles tilted forward up to 45°. For compact storage and transport, the V-22’s wing rotates to align, front-to-back, with the fuselage. The proprotors can also fold in a sequence taking 90 seconds.The V-22’s development processes have been long and controversial. When the development budget, first set at $2.5 billion in 1986, had reached $30 billion in 1988, then-Defense Secretary Dick Cheney zeroed out the budget, but was overruled by Congress. The first flight occurred on March 19, 1989.
(共1票, 平均分: 4)
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(共2票, 平均分: 4.5)