Aircraft Nose wheel Steering Systems and Their Functionality

            When conducting ground operations with an aircraft featuring a nose wheel steering system, control is often provided to the pilot through the flight deck. Depending on the size of the aircraft, various parts and components may be present to allow for efficient steering and braking. As aircraft landing and steering systems are crucial for conducting operations on runways and ground surfaces, understanding their types, construction, and functionalities can be extremely useful for any current or aspiring pilots.

            For smaller and lighter aircraft, a more simplistic aircraft nose wheel steering system may be present. In such assemblies, mechanical linkages are attached to rudder pedals, causing the strut piston axle and wheel assembly to be actuated upon the depression of a pedal. As there are typically left and right pedals provided to the pilot, the direction that the wheel assembly turns is dependent on the input of the pilot.

            For much larger aircraft, such as those serving as passenger airliners or for cargo transportation, a larger amount of power is needed to enact actuator nose gear steering components. As such, hydraulic power serves as the most commonly used power source for steering, and a variety of assemblies may be present to accommodate varying applications and needs. Generally speaking, most assemblies share some common components, including joysticks, wheels, and tillers for the control of the system. For some aircraft, the ability to switch the power state on and off may also be provided.

            To control the flow of hydraulic fluid and its pressure, a control unit is used. This control unit may come in the form of a hydraulic metering or control valve, and fluids are retained in the actuators through the use of an accumulator and relief valve. As such, the steering actuating cylinders may also serve as shimmy dampers. As the ease of steering may be affected depending on the speed that the aircraft is moving, an input subsystem may be in place in order to ensure proper turning. If the aircraft faces a hydraulic failure, safety valves are also common to such assemblies and permit the swiveling of the nose wheel through pressure relief.

            To connect the nose steering wheel to the assembly, a shaft and steering drum are attached together and located within the flight deck control pedestal. By rotating the steering drum, steering signals can be transported to the control drum through cables and pulleys. Once the differential assembly is actuated, the movement is then transferred to a metering valve assembly to actuate the selector valve. Based on the selected position of the valve, hydraulic power can be sent to the nose gear for the means of turning. To ensure that hydraulic pressure does not extend the nose gear past an unsafe angle, various devices are in place to create a maximum limit.

            Shimmy dampers are important for the aircraft nose wheel steering system, ensuring that shuddering is avoided during slower turning speeds. Through the use of hydraulic dampening, the shimmy damper is often placed between the upper and lower shock struts as an external equipment piece. Due to its use for mitigating shuddering, they are relied on during all ground operations.

            In larger aircraft that utilize hydraulic power for steering, shimmy dampers are crucial for removing shuddering forces. For older aircraft that primarily serve for transportation, vane-type steering dampers were most often used. With such equipment, vibrational forces could be lessened while assisting in the steering of the nose wheel.

            For aircraft that are devoid of hydraulic actuator nose gear steering assemblies, external shimmy damper units are placed at the shock strut. To ensure that the lower strut cylinder is incapable of shimmying, hydraulic fluid is supplied to the piston through a bleed hole. By creating a restricted flow, the shimmying of the cylinder is reduced and controlled.

            Beyond such devices, a number of similar components may be used to accommodate varying aircraft and their needs. When you are in the market for premium actuator steering assy parts, steering rod components, and other such items, the experts at Sourcing Streamlined can help you secure everything you need for your operational requirements. As a leading online distributor of aviation parts, we leverage competitive pricing and rapid lead-times for the benefit of our customers. Get started on the purchasing process today and experience how Sourcing Streamlined is revolutionizing the part procurement process for our customers.

1. john jones
2. Posted on February 12, 2021
aviation

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