Saturday, July 7, 2007

Fixed-wing aircraft

A fixed-wing aircraft is a heavier-than-air craft where movement of the wings in relation to the aircraft is not used to generate lift. The term is used to distinguish from rotary-wing aircraft, or ornithopters, where the movement of the wing surfaces relative to the aircraft generates lift. Modern jet transport aircraft take off at roughly 290 km/h (180 mph), and cruise at over 892 km/h (555 mph). Fixed-wing aircraft are commonly called airplanes in North America (the U.S. and Canada), and aeroplanes in Commonwealth countries (other than Canada) and Ireland. These terms are derived from Greek aéros- ("air") and -plane. Both terms are often shortened to just planes.

Fixed-wing aircraft include a large range of craft from small training and recreational aircraft to large airliners and military cargo aircraft. Some aircraft use fixed wings to provide lift only part of the time and may or may not be referred to as fixed-wing.
The word also embraces aircraft with folding or removable wings that are intended to fold when on the ground. This is usually to ease storage or facilitate transport on, for example, a vehicle trailer or the powered lift connecting the hangar deck of an aircraft carrier to its flight deck. It also embraces "variable geometry" aircraft, such as the General Dynamics F-111, Grumman F-14 Tomcat and the Panavia Tornado, which can vary the sweep angle of their wings during flight. There are also rare examples of aircraft which can vary the angle of incidence of their wings in flight, such the F-8 Crusader, which are also considered to be "fixed-wing".


Two necessities for all fixed-wing aircraft (as well as rotary-wing aircraft) are air flow over the wings for lifting of the aircraft, and an open area for landing. The majority of aircraft, however, also need an airport with the infrastructure to receive maintenance, restocking, refueling and for the loading and unloading of crew, cargo and/or passengers. While the vast majority of aircraft land and take off on land, some are capable of take off and landing on ice, aircraft carriers, snow, and calm water.


The aircraft is the second fastest method of transport, after the rocket. Commercial jet aircraft can reach up to 900 km/h. Single-engined aircraft are capable of reaching 175 km/h or more at cruise speed. Supersonic aircraft (military, research and a few private aircraft) can reach speeds faster than sound. The speed record for a plane powered by an air-breathing engine is currently held by the experimental NASA X-43, which reached nearly ten times the speed of sound.
The biggest aircraft currently in service is Antonov An-225, while the fastest currently in production is the Mikoyan MiG-31. The biggest supersonic jet ever produced and currently in service is Tupolev-160.

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