Aircraft wing

Efficient streamlining prevents the configuration of shock waves over the body surface and aircraft wings, which would cause unsteadiness and power loss. The aircraft wing of an airplane has the cross sectional shape of an aerofoil, being broad and arched at the front, flat underneath (sometimes slightly curved), curved on top, and tapered to a sharp point at the rear. Aircraft wing is so twisted that air passing above it is speeded up, reducing pressure below atmospheric pressure, and air passing below it is slower thus increasing pressure and providing a double effect.

Aircraft wing follows from Bernoulli theory and results in a force acting vertically upwards, called lift, which counters the plane weight. In level flight lift equals weight. The aircraft wings develop sufficient lift to support the plane when they move quickly through the air. The thrust that causes propulsion comes from the reaction to the air stream accelerated backwards by the propeller or the gases shooting backwards from the jet exhaust. In flight the engine thrust must conquer the air resistance, or drag. The drag is reduced by streamlining the plane, resulting in higher speed and reduced fuel expenditure for a given power.
A fixed aircraft wing, usually called an airplane, is a heavier than air aircraft able of flight whose lift is generated not by aircraft wing motion relative to the aircraft, but by forward motion during the air. The term is used to differentiate fixed aircraft wing from rotary aircraft wing and ornithopters in which lift is generated by blades or aircraft wings that move relative to the aircraft. Many fixed aircraft wing are propelled forward by the thrust from propellers or jet engines, but the class includes aircraft frequently called gliders. Most fixed aircraft wing are flown by a pilot on board the aircraft, but some are planned to be distantly or computer controlled.