STOL airplane, any of several fixed-wing aircraft capable of taking off and landing on runways considerably shorter than those needed by conventional aircraft. Most aircraft of this type require a runway no more than 150 metres (500 feet) long, which is about 10 times shorter than the average runway. STOL’s were developed to meet the needs exemplified by bush or wilderness flying, where steep climb and approach angles and low landing speed are more important than high cruising speeds. These capabilities are provided by a combination of aerodynamic devices, such as the augmentor wing, which was introduced during the early 1960s. It consists of full span slats at the leading edge of the wing and full span double-slotted flaps at the trailing edge. Manipulation of these devices and an air duct system allows use of air turbulence and prop wash for added lift and drag.
The first version of the modern STOL was test-flown in 1954 by the U.S. Navy. Since then, the STOL has been adopted by the armed forces of the United States and Great Britain for combat operations. It has also been used for short-distance commercial flights in Canada and several other countries since the early 1970s.