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 takeoffs 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 takeoff, 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 takeoff, 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 takeoff distance of 1,200 feet (366 metres).