What is an oleo pneumatic shock absorber?

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.

How does an oleo 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 does oleo imply with regards to shock struts?

a hydraulic device used as a shock absorber in the landing gear of aircraft, consisting of an oil-filled cylinder fitted with a hollow, perforated piston into which oil is slowly forced when a compressive force is applied to the landing gear, as in a landing.

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.

What device in an oleo strut controls the rate of flow between one chamber and the next?

The taper of the pin controls the rate of fluid flow from the bottom cylinder to the top cylinder at all points during the compression stroke. In this manner, the greatest amount of heat is dissipated through the walls of the strut.

What two fluids compose a shock strut?

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.

What are the three types of landing gear struts?

Landing Gear Components & Equipment:

• Struts transmit shock loads of landing, takeoff, and taxi to the airplane structure.
• There are three types of landing gear struts: Bungee.
• Bungee Struts:
• Spring Struts:
• Oleo Struts:

What type of oil is used in an oleo strut?

The main structure of the oleo strut consists of a piston that’s attached to the wheel and a cylinder that’s attached to the airframe. Inside the tubes are what’s generally referred to as oil, but usually is hydraulic fluid, and compressed air or nitrogen.