An oleo strut
is a pneumatic
air–oil hydraulic shock absorber
used on the landing gear
of most large aircraft
and many smaller ones.
This design cushions the impacts of landing and damps out vertical oscillations.
It is undesirable for an airplane to bounce on landing—it could lead to a loss of control. The landing gear should not add to this tendency. A steel coil spring stores impact energy from landing and then releases it. An oleo strut absorbs this energy, reducing bounce.
As the strut compresses, the spring rate increases dramatically, because the air is being compressed, while the viscosity of the oil dampens the rebound movement.
The largest cargo airplanes in the world, such as the Antonov An-124 Ruslan, use oleo struts to allow for rough-field landing capacity with a payload of up to 150 tons. This design also cushions the airframe from the impacts of taxiing.
One of the first serially produced airplanes to use an oleo strut was the Royal Aircraft Factory F.E.2 of 1914.
In the USA, Cleveland Pneumatic Tool Company designed and introduced oleo-pneumatic shock-absorbing strut for airplanes, (later called "Aerol" struts) in 1926.
This page was last edited on 15 May 2018, at 07:57 (UTC)
under CC BY-SA license.