V-22 Osprey

The V-22 Osprey is a joint service, multi-mission aircraft with vertical take-off and landing (VTOL) capability. It performs VTOL missions as effectively as a conventional helicopter while also having the long-range cruise abilities of a twin turboprop aircraft.

The Osprey is the world's first production tiltrotor aircraft with a 38 ft (12 m) rotor, engine, and transmission nacelle mounted on each wing tip. It can operate as a helicopter when taking off and landing vertically. Once airborne, the nacelles rotate forward 90 degrees for horizontal flight, converting the V-22 to a high-speed, fuel-efficient turboprop airplane. The wing rotates for compact storage aboard ship.

The United States Marine Corps is the lead service in the development of the Osprey. The Marine Corps version, the MV-22A, will be an assault transport for troops, equipment and supplies, and will be capable of operating from ships or from expeditionary airfields ashore. The US Navy's HV-22A will provide combat search and rescue, delivery and retrieval of special warfare teams along with fleet logistic support transport. The CV-22A operated by the United States Special Operations Command (USSOCOM) will conduct long-range special operations missions. The V-22 Osprey will replace the Marine Corps CH-46E and CH-53D as well as several types of the Special Operations Command H-53, H-47, H-60, and C-130 series aircraft.

The Osprey's development process has been long, controversial, and convoluted. The first flight occurred in March 1989. Since then however there have been three significant failures during testing - a crash in 1991, another in 1992 that killed seven and a third in April 2000 that killed nineteen. The problem with the Osprey style tiltrotors is that if, in a vertical configuration, one engine fails, the aircraft can suddenly be dangerously out of control (although an axle and transmission system between the engine nacelles is designed to prevent this happening). Similar problems can be induced if the craft descends too quickly, apparently limiting the maximum descent rate to a fraction of what a conventional helicopter can achieve - an obvious concern, as helicopters at low altitude are highly vulnerable to ground fire. The Osprey's limited lift capacity and high cost have also been heavily criticised. Advocates of the program point to the Osprey's ability to carry troops and freight faster, further, and much higher (and thus out of range of much enemy fire) than conventional helicopters. As of May 2004, a decision on whether to put the Osprey into full production is apparently scheduled for early 2005. Planned purchases include 360 for the Marine Corps, 48 for the Navy and 50 for the Air Force.

General Characteristics

• Primary Function: Vertical takeoff and landing (VTOL) aircraft
• Contractor: Bell-Boeing
• Propulsion: Two pivoting Rolls-Royce/Allison AE 1007 engines
• Main rotor diameter: 38 ft (11.58 m)
• Blades per rotor: Three
• Weight: 60,500 lb (27 t) max gross weight
• Ceiling: 25,000 feet (7,600 m) service ceiling
• Speed: 272 knots (500 km/h) cruise
• Armament: Provisions for two 0.5 in (12.7 mm) cabin guns or 0.308 in (7.62 mm) electric gatling guns