A short takeoff and landing (STOL)

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

is a conventional

fixed-wing aircraft A fixed-wing aircraft is a heavier-than-air flying machine, such as an airplane, which is capable of flight using wings that generate lift caused by the aircraft's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinc ...

that has short

runway According to the International Civil Aviation Organization (ICAO), a runway is a "defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft". Runways may be a man-made surface (often asphalt concrete, as ...

requirements for

takeoff and landing Aircraft can have different ways to take off and land. Conventional airplanes accelerate along the ground until sufficient lift is generated for takeoff, and reverse the process to land. Some airplanes can take off at low speed, this being a short ...

. Many STOL-designed aircraft also feature various arrangements for use on

airstrip An aerodrome (Commonwealth English) or airdrome (American English) is a location from which aircraft flight operations take place, regardless of whether they involve air cargo, passengers, or neither, and regardless of whether it is for publ ...

s with harsh conditions (such as

high altitude Altitude or height (also sometimes known as depth) is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The exact definition and reference datum varies according to the context ...

or ice). STOL aircraft, including those used in scheduled passenger airline operations, have also been operated from

STOLport A STOLport or STOLPORT was an airport designed with STOL (Short Take-Off and Landing) operations in mind, usually for an aircraft class of certain weight and size. The term "STOLport" did not appear to be in common usage as of 2008, although was c ...

airfields which feature short runways.

Design considerations

87 GAF Nomad 22SL Philippine Air Force (7838564596)

Many

fixed-wing A fixed-wing aircraft is a heavier-than-air flying machine, such as an airplane, which is capable of flight using wings that generate lift caused by the aircraft's forward airspeed and the shape of the wings. Fixed-wing aircraft are distinct ...

STOL aircraft are

bush plane A bush airplane is a general aviation aircraft used to provide both scheduled and unscheduled passenger and flight services to remote, undeveloped areas, such as the Canadian north or bush, Alaskan tundra, the African bush, or savanna, Amazon ra ...

s, though some, like the

de Havilland Canada Dash-7 The de Havilland Canada DHC-7, popularly known as the Dash 7, is a turboprop-powered regional airliner with short take-off and landing (STOL) performance. It first flew in 1975 and remained in production until 1988 when the parent company, ...

, are designed for use on prepared airstrips; likewise, many STOL aircraft are taildraggers, though there are exceptions like the

PAC P-750 XSTOL The PAC P-750 XSTOL, (formerly known as the PAC 750XL) is a utility aircraft of conventional all-metal low-wing monoplane design, with fixed tricycle undercarriage. Combining the engine and wings of the PAC Cresco with a new large fuselage and ...

, the

Quest Kodiak The Daher Kodiak (formerly Quest Kodiak) is an American utility aircraft designed by and originally manufactured by Quest Aircraft. Manufacturing was taken over by Daher in 2019 after its purchase of Quest Aircraft. The high-wing, unpressuri ...

, the

de Havilland Canada DHC-6 Twin Otter The de Havilland Canada DHC-6 Twin Otter is a Canadian STOL (Short Takeoff and Landing) utility aircraft developed by de Havilland Canada, which produced the aircraft from 1965 to 1988; Viking Air purchased the type certificate, then restarted ...

and the

Peterson 260SE The Wren 460 is a STOL conversion of a Cessna 180 or 182 airframe. Design and development The Wren 460 traces its history to the Skyshark, a modification of the earlier Robertson Skylark SRX-1, built by James Robertson, son of Robertson Aircra ...

Autogyro An autogyro (from Greek and , "self-turning"), also known as a ''gyroplane'', is a type of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. Forward thrust is provided independently, by an engine-driven propeller. Whi ...

s also have STOL capability, needing a short ground roll to get airborne, but capable of a near-zero ground roll when landing.

Runway According to the International Civil Aviation Organization (ICAO), a runway is a "defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft". Runways may be a man-made surface (often asphalt concrete, as ...

length requirement is a function of the square of the minimum flying speed (

stall speed In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases.Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', p. 486. Aviation Supplies & Academics, 1997. This occurs when the ...

), and most design effort is spent on reducing this number. For

takeoff Takeoff is the phase of flight in which an aerospace vehicle leaves the ground and becomes airborne. For aircraft traveling vertically, this is known as liftoff. For aircraft that take off horizontally, this usually involves starting with a t ...

, large power/weight ratios and low drag help the plane to accelerate for flight. The landing run is minimized by strong

brake A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction. Background ...

s, low landing speed,

thrust reverser Thrust reversal, also called reverse thrust, is the temporary diversion of an aircraft engine's thrust for it to act against the forward travel of the aircraft, providing deceleration. Thrust reverser systems are featured on many jet aircraft ...

s or

spoiler Spoiler is a security vulnerability on modern computer central processing units that use speculative execution. It exploits side-effects of speculative execution to improve the efficiency of Rowhammer and other related memory and cache attacks. Ac ...

s (less common). Overall STOL performance is set by the length of runway needed to land or take off, whichever is longer. Fieseler Storch (7582553016)

Of equal importance to short ground run is the ability to clear obstacles, such as hills, on both take off and landing. For takeoff, large power/weight ratios and low drag result in a high rate of climb required to clear obstacles. For landing, high drag allows the aeroplane to descend steeply to the runway without building excess speed resulting in a longer ground run. Drag is increased by use of

flap Flap may refer to: Arts, entertainment, and media * ''Flap'' (film), a 1970 American film * Flap, a boss character in the arcade game ''Gaiapolis'' * Flap, a minor character in the film '' Little Nemo: Adventures in Slumberland'' Biology and he ...

s (devices on the wings) and by a

forward slip A slip is an aerodynamic state where an aircraft is moving ''somewhat'' sideways as well as forward relative to the oncoming airflow or relative wind. In other words, for a conventional aircraft, the nose will be pointing in the opposite directio ...

(causing the aeroplane to fly somewhat sideways through the air to increase drag). Normally, a STOL aircraft will have a large

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is expres ...

for its weight. These wings often use

aerodynamic Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...

devices like flaps, slots,

slats Super Low Altitude Test Satellite (SLATS) or Tsubame was a JAXA satellite intended to demonstrate operations in very low Earth orbit (VLEO, below 200 km), using ion engines to counteract aerodynamic drag from the Earth's atmosphere which i ...

, and

payload Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...

lifting ability. The payload is critical, because many small, isolated communities rely on STOL aircraft as their only transportation link to the outside world for passengers or cargo; examples include many communities in the

Canadian north Bradley Air Services, operating as Canadian North, is a wholly Inuit-owned airline headquartered in Kanata, Ontario, Canada. It operates scheduled passenger services to communities in the Northwest Territories, Nunavut and the Nunavik region o ...

and

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., ...

. Most STOL aircraft can

land Land, also known as dry land, ground, or earth, is the solid terrestrial surface of the planet Earth that is not submerged by the ocean or other bodies of water. It makes up 29% of Earth's surface and includes the continents and various islan ...

either on- or off-airport. Typical off-airport landing areas include snow or ice (using skis), fields or gravel riverbanks (often using special fat, low-pressure

tundra tire A tundra tire (UK: ''tundra tyre'') is a large low-pressure tire used on light aircraft to allow operations on rough terrain. A common variant of tundra tire is the bushwheel brand. These tires include an integral inner tube with the valve man ...

s), and water (using

float Float may refer to: Arts and entertainment Music Albums * ''Float'' (Aesop Rock album), 2000 * ''Float'' (Flogging Molly album), 2008 * ''Float'' (Styles P album), 2013 Songs * "Float" (Tim and the Glory Boys song), 2022 * "Float", by Bush ...

s): these areas are often extremely short and obstructed by tall trees or hills. Wheel skis and amphibious floats combine wheels with

ski A ski is a narrow strip of semi-rigid material worn underfoot to glide over snow. Substantially longer than wide and characteristically employed in pairs, skis are attached to ski boots with ski bindings, with either a free, lockable, or partial ...

s or floats, allowing the choice of landing on snow/water or a prepared runway.

Kits

A number of aircraft modification companies offer STOL kits for improving short-field performance. *

Crosswinds STOL A crosswind is any wind that has a perpendicular component to the line or direction of travel. This affects the aerodynamics of many forms of transport. Moving non-parallel to the wind's direction creates a crosswind component on the object and th ...

Wasilla, Alaska Wasilla ( Dena'ina: ''Benteh'') is a city in Matanuska-Susitna Borough, United States and the fourth-largest city in Alaska. It is located on the northern point of Cook Inlet in the Matanuska-Susitna Valley of the southcentral part of the st ...

, sells STOL kits for light aircraft, including

leading edge cuff A leading-edge cuff is a fixed aerodynamics, aerodynamic wing device employed on fixed-wing aircraft to improve the Stall (flight), stall and spin (aerodynamics), spin characteristics. Cuffs may be either factory-designed or an after-market add- ...

s, tip spill plates, inboard flap extensions and STOL fences. The company offers kits for

Piper PA-12 The Piper PA-12 Super Cruiser is an American three-seat, high wing, single-engine conventional landing gear-equipped light aircraft that was produced by Piper Aircraft between 1946-48. The PA-12 was an upgraded and redesignated Piper J-5.Plan ...

, PA-14, PA-18, PA-20 and 22, Bellanca Champion Model 7 series, Cessna 170B,

180 __NOTOC__ Year 180 ( CLXXX) was a leap year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Rusticus and Condianus (or, less frequently, year 933 '' Ab ...

and 185. * Horton, Inc, of

Wellington, Kansas Wellington is a city in and the county seat of Sumner County, Kansas, United States. As of the 2020 census, the population of the city was 7,715. History 19th century Wellington was platted in 1871 and named for the Duke of Wellington. It w ...

, offers STOL kits under the brand name ''Horton STOL-Craft'', emphasizing that the modifications increase safety by allowing forced landings to occur at lower speeds and thus improve survivability. The Horton modifications include a drooped

, conical cambered

wingtip A wing tip (or wingtip) is the part of the wing that is most distant from the fuselage of a fixed-wing aircraft. Because the wing tip shape influences the size and drag of the wingtip vortices, tip design has produced a diversity of sha ...

s, control surface gap seals and

wing fence Wing fences, also known as boundary layer fences and potential fences are fixed aerodynamic devices attached to aircraft wings. Often seen on swept-wing aircraft, wing fences are flat plates fixed to the upper surfaces parallel to the wing ch ...

s. The company says: "On an average you can expect to get a 4-7 knot reduction in stall speeds. Flying at these lower stall speeds you can reduce the take-off and landing distances by 10%". Horton STOL kits are available for several

Cessna Cessna () is an American brand of general aviation aircraft owned by Textron Aviation since 2014, headquartered in Wichita, Kansas. Originally, it was a brand of the Cessna Aircraft Company, an American general aviation aircraft manufacturing c ...

and

Piper PA-28 The Piper PA-28 Cherokee is a family of two-seat or four-seat light aircraft built by Piper Aircraft and designed for flight training, air taxi and personal use.Plane and Pilot: ''1978 Aircraft Directory'', pages 62–64. Werner & Werner Corp, ...

models. * Micro AeroDynamics markets

vortex generator A vortex generator (VG) is an aerodynamic device, consisting of a small vane usually attached to a lifting surface (or airfoil, such as an aircraft wing) or a rotor blade of a wind turbine.elevator An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...

and on the fin. Kits are available for a large number of light aircraft types. * Sierra Industries sells Robertson STOL kits, marketed under the name R/STOL, incorporate a drooped leading edge cuff, wing fences, drooping ailerons and an automatic trim system. The company says that installation "allows 15 to 25 MPH slower approaches and requires up to 40% less runway distance". R/STOL kits are available for various Cessna models. * Stolairus Aviation of Kelowna, British Columbia, has developed STOL Kits for the

de Havilland Canada DHC-2 Beaver The de Havilland Canada DHC-2 Beaver is a single-engined high-wing propeller-driven short takeoff and landing (STOL) aircraft developed and manufactured by de Havilland Canada. It has been primarily operated as a bush plane and has been used ...

and

de Havilland Canada DHC-3 Otter The de Havilland Canada DHC-3 Otter is a single-engined, high-wing, propeller-driven, short take-off and landing ( STOL) aircraft developed by de Havilland Canada. It was conceived to be capable of performing the same roles as the earlier and ...

to increase lift and reduce stall speeds. The DHC-2 Beaver STOL Kit includes a contoured leading edge, flap-gap seals, wing fences and drooped wingtips. The DHC-3 Otter STOL Kit includes a contoured leading edge and drooped wingtips.

STOLport

is an airport designed with STOL operations in mind, normally having a short single runway. STOLports are not common but can be found, for example, at

London City Airport London City Airport is a regional airport in London, England. It is located in the Royal Docks in the Borough of Newham, approximately east of the City of London and east of Canary Wharf. These are the twin centres of London's financial ...

London London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

. There were also several STOLports in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

that were used for scheduled passenger airline operations but are now no longer in existence.

CESTOL

Cruise-efficient short takeoff and landing (CESTOL), is an aircraft with both very short runway requirements and high cruise speeds (greater than Mach 0.8).

Definitions

Many different definitions of STOL have been used by different authorities and nations at various times and for a myriad of regulatory and military purposes. Some accepted definitions of STOL include: Additionally, some aircraft manufacturers market their products as STOL without providing evidence that the aircraft meets any accepted definition.

References

External links

*
Anatomy of a STOL Aircraft: Designing a Modern Short Take-Off and Landing Aircraft by Chris Heintz
{{Types of take-off and landing Types of take-off and landing