What does an oleo pneumatic undercarriage system compresses?

During landing, or when the aircraft taxis over bumps, the piston slides up and down. This movement compresses the gas, which acts as a spring, and forces oil through the orifice, which acts as a damper.

What is an oleo pneumatic shock absorber and how does it work?

Oleo struts absorb and dissipate shock loads using a combination of two fluids — a gas and a hydraulic fluid — contained in two chambers — a cylinder and a piston.

How does an oleo strut dampen the shock of landing?

The “oleo” strut uses compressed air or nitrogen combined with hydraulic fluid to absorb and dissipate the shock of landing, and to damp the recoil to minimize bounced landings.

What is oleo pneumatic strut?

The oleo pneumatic shock absorber consists of an upper chamber and a lower chamber of cross-sectional area A. Both the chambers are connected via an orifice of area í µí°´. µí°´. Most of the landing gear shock absorbers have a …

How much hydraulic fluid should be put into an oleo strut?

around a gallon
Typically it takes around a gallon of hydraulic fluid to service three struts. Nitrogen is better than compressed air for strut servicing because it is drier and doesn’t vary in pressure as much as air; it is also less corrosive to the inside of the strut housing.

What material is used inside of a landing gear shock oleo strut?

The last type of strut is the only one that is a true shock absorber. Shock struts, often called oleo or air/oil struts, use a combination of nitrogen (or sometimes compressed air) and hydraulic fluid to absorb and dissipate shock loads on landing.

How much pressure is on a strut?

Generally main struts should be inflated so that around five inches of the piston is exposed, and nose struts to around four inches. The exact range for each model can be found in the service manual. The struts should be inflated so that they are within the proper range even when the airplane is fully loaded.

How do you service a shock and strut?

Release any air pressure in the shock strut. Remove the air service valve assembly. Fill the strut to the level of the service port with approved hydraulic fluid. Attach the bleed hose to the service port and insert the free end of the hose into a container of clean hydraulic fluid.

What is the purpose of struts in cars?

Shocks and struts help stabilize your vehicle’s movements, enhancing control when you turn, brake, accelerate or encounter uneven road surfaces. Today’s vehicles use shocks, struts or a combination of the two.

What is oleo pneumatic shock absorber?

An oleo-pneumatic strut is an air–oil hydraulic shock absorber used on the landing gear of most large aircraft and many smaller ones. Oleo-pneumatic shock absorber is considered the safest and the most efficient modern shock absorption type with efficiencies up to 90%.

What is an oleo strut on a plane?

Oleo strut. 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.

Who invented the oleo pneumatic strut?

The original design for the oleo-pneumatic shock-absorbing strut was patented by British manufacturing conglomerate Vickers Armstrong during 1915. It had been derived from the recuperative gear design of the Vickers gun, controlling recoil by forcing oil through precisely sized orifices.