STOL
STOL is an acronym for
Short Take-Off and Landing, used in the
aircraft industry to describe
aeroplanes with very short
runway requirements. Many STOL aircraft are
bush planes, though some, like the
de Havilland Dash-7, are designed for use on prepared airstrips; likewise, many STOL aircraft are
taildraggers, though there are exceptions like the
de Havilland Twin Otter and the
Peterson 260SE.
Runway length requirement is a function of the square of the minimum flying speed (
stall speed), and most design effort is spent on reducing this number. For
takeoff, large
power/weight ratios and low
drag help the plane to accelerate for flight. The landing run is minimized by strong
brakes, low landing speed or
spoilers (less common). Overall STOL performance is set by the length of runway needed to land or take off, whichever is longer.
Of equal importance to short ground run is the ability to clear obstacles, such as trees, 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
flaps (devices on the wings) and by a
forward slip (causing the aeroplane to fly somewhat sideways though the air to increase drag).
Normally, a STOL plane will have a large
wing for its weight. These wings often use
aerodynamic devices like flaps,
slots,
slats, and
vortex generators. Typically, designing an aeroplane for excellent STOL performance reduces maximum speed, but does not reduce
payload 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 and
Alaska.
|
A Zenair CH701 STOL light aircraft |
Most STOL aeroplanes can
land 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 tires), and water (using
floats): these areas are often extremely short and obstructed by tall trees or hills. Wheel skis and amphibious floats combine wheels with
skis or floats, allowing the choice of landing on snow/water or a prepared runway. A STOLPORT is an airport designed with STOL operations in mind, normally having a short single runway. These are not common but can be found, for example, at
London City Airport, London, England.
*
Alenia G.222*
Antonov An-72*
BAe 146*
Boeing C-17*Crouch-Bolas Dragonfly
*
Dornier Do 228*
Fieseler Fi 156*
De Havilland Canada DHC-2 Beaver*
De Havilland Canada DHC-4 Caribou*
De Havilland Canada DHC-6 Twin Otter*
De Havilland Canada Dash 7*
De Havilland Canada Dash 8*
Helio Courier*Hunting H126
*
Ilyushin Il-76*
Israel Aircraft Industries Arava
*
Jetpod*
Lockheed C-130*
Wren 460 and Peterson 260SE*
Pilatus PC-6*
Piper Cub*
PZL-104 Wilga*
Saab Gripen*
Saab Viggen*
Westland Lysander *
Kitfox*Zenith
STOL CH 701*
VTOL
