Light airplanes generally are provided with nosewheel steering capabilities through a simple system of mechanical linkage connected to the rudder pedals. Most common applications utilize push/pull rods to connect the pedals to fittings located on the pivotal portion of the nosewheel strut.
Large aircraft, with a need for more positive control, utilize a separate power source for nosewheel steering. Even though nosewheel steering system units of large aircraft differ in their construction features, basically all of them work in approximately the same manner and require: (1) a cockpit control, such as a wheel, handle, lever, or switch to allow for starting and stopping the swiveling movement of the nosewheel and to control the action of the system; (2) mechanical, electrical, or hydraulic connections for transmitting cockpit control movements to a steering control unit on the nosewheel; (3) a control unit, which is usually a metering or control valve; (4) a source of power, which is, in most instances, the airplane's hydraulic system.
Under certain conditions nosewheels vibrate and shimmy during taxiing, takeoff, or landing. If shimmy becomes excessive, it can damage the nose gear or attaching structure. Many airplanes, though, have nosewheel steering systems with built in features to prevent the shimmy.