The most widely used shock absorber for aircraft is the air-oil shock absorber, commonly known as what?

• A. Oleo strut
• B. Shock absorber
• C. Leaf spring
• D. Hydraulic damper

Answer: (A)

The air-oil shock absorber, known as an oleo strut, is the standard landing gear damper because it provides both energy absorption and a spring force in a compact, sealed unit. When the wheel contacts the runway, the piston pushes oil through small passages, creating controlled damping that slows the deceleration and reduces peak loads transmitted to the airframe. At the same time, nitrogen gas (or another gas) on the opposite side of the piston compresses, supplying a spring-like force that cushions the impact and supports the gear during extension. This gas spring also prevents oil cavitation and ensures a smooth rebound, helping the gear return to its ready position after touchdown.

Compared with a generic “shock absorber,” the oleo strut’s combination of dampening and gas spring is essential for managing the high-energy, variable loads of an aircraft landing. Leaf springs are largely used on older or smaller aircraft, not the typical modern gear, and a hydraulic damper alone lacks the built-in spring action that the oleo strut provides.