It is designed with both vertical takeoff and landing (VTOL), and short takeoff and landing (STOL) capabilities to combine the functionality of a conventional helicopter with the long-range, high-speed cruise performance of a turboprop 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 is classified as a powered lift aircraft by the Federal Aviation Administration. For takeoff and landing, it typically operates as a helicopter with the nacelles vertical and rotors horizontal. 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 aircraft. STOL rolling-takeoff and landing capability is achieved by having the nacelles tilted forward up to 45°. Other orientations are possible. It has a ferry range of over 2,100 nmi. Its operational range is 1,100 nmi. Composite materials make up 43% of the airframe, and the proprotor blades also use composites. For storage, the V-22's rotors fold in 90 seconds and its wing rotates to align, front-to-back, with the fuselage. Due to the requirement for folding rotors, their 38-foot (11.6 m) diameter is 5 feet (1.5 m) less than optimal for vertical takeoff, resulting in high disk loading. Most missions use fixed wing flight 75% or more of the time, reducing wear and tear and operational costs. This fixed wing flight is higher than typical helicopter missions allowing longer range line-of-sight communications for improved command and control. Exhaust heat from the V-22's engines can potentially damage ships' flight decks and coatings. Naval Air Systems Command (NAVAIR) devised a temporary fix of portable heat shields placed under the engines, and determined that a long-term solution would require redesigning decks with heat resistant coating, passive thermal barriers, and ship structure changes. Similar changes are required for F-35B operations. In 2009, DARPA requested solutions for installing robust flight deck cooling. A heat-resistant anti-skid metal spray named Thermion has been tested on USS Wasp. For more deetails on the development, design and operational history of the V-22 and its seven variants, click here. Specifications below are for the MV-22B Marine Corps variant.
