What’s the definition of STOL in aviation?

The acronym STOL is used in aviation as a short form for Short Take Off and Landing, and it refers to the length of runway, land or water required for take-offs and landings. A STOL aircraft is defined as an aircraft that is ideal for take-offs and landings in a small area of land or water.

In order to reduce the length of runway required, significant effort is focused on having a low minimum flying speed (also known as stall speed). This is because STOL distance is most closely related to this number. When it comes to take-off, large power/weight ratios and a low amount of drag help a plane accelerate into flight. On the other hand, the landing runway requirement is decreased by strong brakes, a low landing flight speed, and thrust reversers or spoilers.

STOL Short Take Off and LandingOverall STOL performance is a measurement of the length of runway needed to land or take-off, whichever is longer. STOL performance for the Viking Twin Otter Series 400 is shown in the diagram here.
The Twin Otter is the only utility turbine to offer a STOL performance capability with take-off distance of 1,200 feet (366 metres).