The Aircraft Hydraulic System

An aircraft hydraulic system allows for forces to be applied, multiplied, and transmitted from one location to another through an incompressible fluid medium. Hydraulics are a critical system on almost all modern aircraft. Light aircraft primarily make use of hydraulics to augment and transmit braking forces from the cockpit to the brake disk or drum. Larger, more complex aircraft may use hydraulics to actuate landing gear, flaps and control surfaces in addition to braking and nose-wheel steering.
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Aircraft Landing Gear Design

The landing gear, or undercarriage, has two primary requirements: (1) to support the aircraft while on the ground and (2) to absorb the large loads associated with landing, and transfer these from the wheels to the aircraft’s primary structure. This post will examine the various landing gear systems in operation, describe the components used to absorb the landing loads, and introduce some common gear retraction systems in use today.
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Aircraft Braking Systems

All modern aircraft are fitted with a braking system to assist in slowing and stopping when on the ground. Brakes are used not only to decelerate during a landing run, but also to hold the aircraft during an engine run-up, and in some cases to steer the aircraft through differential braking. Brakes are fitted to the main landing gear but not generally to the nose or tail wheel.

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An Introduction to Aircraft Wheels and Tires

The wheels and tires (tyres) fitted to an aircraft are designed to support the full weight of that aircraft while on the ground, and transmit the static and dynamic loads generated during taxi, take-off and landing into the aircraft’s shock absorption system (typically an oleo-pneumatic shock absorber or steel spring). The largest loads that the wheel/tire assembly sees occur during landing and are characterised by high speeds and large impact loads which deforms the tires, loading the wheel at the flanges. This tutorial focuses on the design and construction of the wheel and tire assembly as fitted to a typical aircraft.
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