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STOL

From Wikipedia, the free encyclopedia
For other uses, seeStol (disambiguation).
AZenair CH 701STOL light aircraft

Ashort takeoff and landing(STOL)aircraftis aconventionalfixed-wing aircraftthat has shortrunwayrequirements fortakeoff and landing.Many STOL-designed aircraft also feature various arrangements for use onairstripswith harsh conditions (such ashigh altitudeor ice). STOL aircraft, including those used in scheduled passenger airline operations, have also been operated fromSTOLportairfields which feature short runways.

Design considerations[edit]

GAF Nomadof the Philippine Air Force

Manyfixed-wingSTOL aircraft arebush planes,though some, like thede Havilland Canada Dash-7,are designed for use on prepared airstrips; likewise, many STOL aircraft aretaildraggers,though there are exceptions like thePAC P-750 XSTOL,theQuest Kodiak,thede Havilland Canada DHC-6 Twin Otterand thePeterson 260SE.Autogyrosalso have STOL capability, needing a short ground roll to get airborne, but capable of a near-zero ground roll when landing.[citation needed]

Runwaylength requirement is a function of the square of the minimum flying speed (stall speed), and most design effort is spent on reducing this number. Fortakeoff,largepower/weight ratiosand lowdraghelp the plane to accelerate for flight. The landing run is minimized by strongbrakes,low landing speed,thrust reversersorspoilers(less common). Overall STOL performance is set by the length of runway needed to land or take off, whichever is longer.[1]

Fieseler Storchwith GermanLuftwaffemarkings

Of equal importance to short ground run is the ability to clear obstacles, such as hills, on both take off and landing. For takeoff, largepower/weight ratiosand 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 offlaps(devices on the wings) and by aforward slip(causing the aeroplane to fly somewhat sideways through the air to increase drag).[citation needed]

Normally, a STOL aircraft will have a largewingfor its weight. These wings often useaerodynamicdevices like flaps,slots,slats,andvortex generators.[2]Typically, designing an aircraft for excellent STOL performance reduces maximum speed, but does not reducepayloadlifting 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 theCanadian northandAlaska.[citation needed]

Most STOL aircraft canlandeither on- or off-airport. Typical off-airport landing areas include snow or ice (using skis), fields or gravel riverbanks (often using special fat, low-pressuretundra tires), and water (usingfloats): these areas are often extremely short and obstructed by tall trees or hills. Wheel skis and amphibious floats combine wheels withskisor floats, allowing the choice of landing on snow/water or a prepared runway.[citation needed]

Kits[edit]

Micro Dynamics vortex generators mounted on the wing of aCessna 182K

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

  • Crosswinds STOLofWasilla, Alaska,sells STOL kits for light aircraft, includingleading edge cuffs,tip spill plates, inboard flap extensions and STOL fences. The company offers kits forPiper PA-12,PA-14,PA-18,PA-20 and 22,Bellanca Champion Model 7 series,Cessna 170B,180and185.[3]
  • Horton, Inc,ofWellington, Kansas,offers STOL kits under the brand nameHorton 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 droopedleading edge cuff,conical camberedwingtips,control surface gap seals andwing fences.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 severalCessnaandPiper PA-28models.[4][5][6]
  • Micro AeroDynamicsmarketsvortex generatormodification kits for "STOL benefits". The Micro kits are small vortex generators that are glued to the wing leading edge, as well as the underside of theelevatorand on the fin. Kits are available for a large number of light aircraft types.[7]
  • Sierra Industriessells 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.[8][9][10]
  • Stolairus Aviationof Kelowna, British Columbia, has developed STOL Kits for thede Havilland Canada DHC-2 Beaverandde Havilland Canada DHC-3 Otterto 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.[11]

STOLport[edit]

Main article:STOLport

ASTOLportis an airport designed with STOL operations in mind, normally having a short single runway.[12][13]

STOLports are not common but can be found, for example, atLondon City AirportinLondon,United Kingdom.There were also several STOLports in theUnited Statesthat were used for scheduled passenger airline operations but are now no longer in existence.

CESTOL[edit]

Cruise-efficient short takeoff and landing (CESTOL), is an aircraft with both very short runway requirements and high cruise speeds (greater thanMach0.8).[2][14][15]

Definitions[edit]

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.[16]Some accepted definitions of STOL include:

short takeoff and landing: (DOD/NATO) The ability of an aircraft to clear a 50-foot (15 meters) obstacle within 1,500 feet (450 meters) of commencing takeoff or in landing, to stop within 1,500 feet (450 meters) after passing over a 50-foot (15 meters) obstacle. Also called STOL.

— Department of Defense Dictionary of Military and Associated Terms (JP 1-02)[17]

STOL (Short Take Off and Landing). STOL performance of an aircraft is the ability of aircraft to take off and clear a 50-foot obstruction in a distance of 1,500 feet from beginning the takeoff run. It must also be able to stop within 1,500 feet after crossing a 50-foot obstacle on landing.

— Dictionary of Aeronautical Terms[18]

An aircraft that, at some weight within its approved operating weight, is capable of operating from a STOL runway in compliance with the applicable STOL characteristics and airworthiness, operations, noise, and pollution standards "and" "aircraft" means any machine capable of deriving support in the atmosphere

— Transport Canada[19][20]andArizona Department of Transportation[21]

A STOL aircraft is an aircraft with a certified performance capability to execute approaches along a glideslope of 6 degrees or steeper and to execute missed approaches at a climb gradient sufficient to clear a 15:1 missed approach surface at sea level... A STOL runway is one which is specifically designated and marked for STOL aircraft operations, and designed and maintained to specified standards.

— USFederal Aviation Administration[22]

Heavier-than-air craft that cannot take off and land vertically, but can operate within areas substantially more confined than those normally required by aircraft of the same size. Derived from short takeoff and landing aircraft.

— McGraw-Hill Dictionary of Scientific & Technical Terms[23]

short takeoff and landing aircraft (STOL), heavier-than-air craft, capable of rising from and descending to the ground with only a short length of runway, but incapable of doing so vertically. The precise definition of an STOL aircraft has not been universally agreed upon. However, it has been tentatively defined as an aircraft that upon taking off needs only 1,000 ft (305 m) of runway to clear a 50-ft (15-m) obstacle at the end of that distance and upon landing can clear the same obstacle and then land within 1,000 ft.

— Columbia Encyclopedia[16]

The STOL mode of flight is one during which an airplane taking off or landing is operated at climb-out and approach speeds lower than the conventionally accepted margins of airspeed above the power-off stalling speed of the airplane.

— Lieutenant Colonel Walter P. Maiersperger, USAF (Ret)[24]

Additionally, some aircraft manufacturers market their products as STOL without providing evidence that the aircraft meets any accepted definition.[25]

See also[edit]

References[edit]

  1. ^"What's the definition of STOL in aviation?".Viking Air Ltd.2015-12-02.Retrieved2021-12-20.
  2. ^ab"Powered Lift: Novel GTRI Design Would Let Commercial Jets Use Smaller Airports While Reducing Noise".Georgia Tech Research Institute.Retrieved2010-10-28.
  3. ^Crosswinds S.T.O.L. Inc. (2011)."Crosswinds STOL Inc".Retrieved2011-02-23.
  4. ^Horton, Inc."Description of the Horton STOL Kit".Retrieved2009-12-26.
  5. ^Horton, Inc."Frequently Asked Questions About the Horton STOL Kit".Retrieved2009-12-26.
  6. ^Horton, Inc."Horton STOL Kit Pricing".Retrieved2009-12-26.
  7. ^Micro AeroDynamics Inc (2009)."Micro Vortex Generators for Single and Twin Engine Aircraft".Retrieved2009-12-26.
  8. ^Sierra Industries (2007)."Sierra R/STOL High Lift Systems for Piston Engine Aircraft".Retrieved2009-12-26.
  9. ^Sierra Industries (2007)."Sierra R/STOL Performance Comparison Charts".Retrieved2009-12-26.
  10. ^Sierra Industries (2007)."Modifications - Sierra R/STOL High Lift Systems for Piston Engine Aircraft".Retrieved2009-12-26.
  11. ^"DHC-2 Beaver."Stolairus Retrieved: February 2, 2012.
  12. ^Starting STOLTime Magazine.Aug. 16, 1968.
  13. ^Stolport ManualArchived2006-10-13 at theWayback Machine(Doc 9150)International Civil Aviation Organization(ICAO)
  14. ^Hange, Craig E (2005-04-25)."Short Field Take-Off and Landing Performance as an Enabling Technology for a Greener, More Efficient Airspace System"(PDF).Ames Research Center,NASA.Retrieved2010-10-28.
  15. ^"Novel Design".Aerospace Manufacturing and Design. May 2011.Retrieved2011-05-08.
  16. ^abColumbia Encyclopedia."short takeoff and landing aircraft".Answers.com.Retrieved2009-12-25.
  17. ^"Department of Defense Dictionary of Military and Associated Terms (JP 1-02)".United States Department of Defense.Archived fromthe originalon 2011-06-05.Retrieved2009-12-22.
  18. ^Crane, Dale:Dictionary of Aeronautical Terms, third edition,page 492. Aviation Supplies & Academics, 1997.ISBN1-56027-287-2
  19. ^Transport Canada(November 2009)."Glossary for Pilots and Air Traffic Services Personnel (TP 1158E)".Retrieved2009-12-15.
  20. ^Transport Canada(September 2009)."Aeronautics Act - November 2007 Consolidation".Retrieved2009-12-25.
  21. ^Arizona Department of Transportation."Appendix B"(PDF).Archived fromthe original(PDF)on March 14, 2009.Retrieved2009-12-15.
  22. ^US House of Representatives Committee of Science and Technology (July 1984)."Statement of John Kern, Deputy Director of Flight Operations, FAA"(PDF).Retrieved2009-12-15.
  23. ^McGraw-Hill Dictionary of Scientific & Technical Terms (2003)."STOL aircraft".Retrieved2009-12-25.
  24. ^Maiersperger, Walter P., Lieutenant Colonel, USAF (Ret) (March–April 1968)."What is STOL?".Retrieved2009-12-25.{{cite web}}:CS1 maint: multiple names: authors list (link)
  25. ^Fisher Flying Products."Horizon 1".Retrieved2009-10-27.

External links[edit]

External videos
video iconSTOL Ultralight taking off and landing
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