Retractable Landing Gear Systems and Their Operation
Landing gear is paramount to any aircraft, allowing them to safely touchdown on a runway or surface for the means of finishing a flight operation. As landing gear can serve as a source of drag as equipment disrupts airflow, it can be very beneficial to minimize its effects for the most advantageous aerodynamic properties. With a retractable landing gear system, the landing gear of an aircraft may be deployed and retracted as needed to increase climb performance and cruise airspeeds. In this blog, we will discuss the retractable landing gear system and its benefits to flight operations.
In order to create the force needed to deploy or retract landing gear, such systems operate using hydraulic, electric, or electrohydraulic power. The hydraulic landing system relies on hydraulic fluids kept under pressure for the actuation of linkages that are charged with gear extension and retraction. The hydraulic pump may be engine driven or electrically powered for increasing fluid pressure, and limit switches and relief valve components are commonly implemented to mitigate excessive pressure conditions. When the hydraulic landing system utilizes electricity for the pump’s operation, it is considered an electrohydraulic system.
With an electrical retractable landing gear system, an electric motor may be used for gear operations. Through the actuation of a switch in the flight deck, an electric motor is activated for the means of raising or lowering equipment based on whether the switch is placed in the UP or DOWN position. When the switch is actuated, the electric gear motor will continuously operate until the up or down limit of the gear switch is tripped. In order to achieve the strength necessary for such operations, the electrical retractable landing gear system relies on shafts, adaptors, gears, and a torque tube which transmit force to drag strut linkages.
Whether a landing gear system is hydraulic, electric, or electrohydraulic, the means of controlling such equipment may be found in the flight deckin the form of a switch. To differentiate the switch, the component is often designed to be shaped like a wheel. While the landing gear switch may vary by aircraft, the most common designs will feature lighting groups for indications. Typically, these lights will be used to convey whether the landing gear is down and locked, retracted, or in another state. In some instances, a warning indicator in the flight deck will be used to notify pilots when gear is in motion or when it is unsafe to land.
To ensure the safe operation of landing gear systems, manufacturers implement a variety of safety devices. When the aircraft is prepared for a touchdown and the landing gear has not been deployed, many aircraft will have a warning horn that will audibly notify the pilots. It is also important that the landing gear is not accidentally retracted while on the ground, and safety switch components, ground locks, and down locks may all be used to prevent accidental operation. If the landing gear is unable to be deployed and is stuck due to the failure of a component, the emergency extension system will allow manual release of equipment so that the aircraft may land. The force needed for emergency deployment typically comes from an accumulator, auxiliary hand pump, or an electrically-powered hydraulic pump.
As retractable landing gear systems are complex, they should always be carefully inspected during the preflight stage of every flight to ensure that there are no issues warranting maintenance or replacement. It is important to look over the switching system and its functionality, and the indicator should display the correct states of equipment when powered. For the external inspection of the assembly, one should check for any debris, damage, or obstructions which could hinder operations. Shock struts should be properly inflated, and all cylinders, drive gears, linkages, sprockets, and other assembly parts should be checked over as well.
To ensure that your retractable landing gear system continues to operate efficiently, it is crucial that regular inspection and maintenance procedures are conducted so that aging or damaged components may quickly be replaced before they cause a major issue. Aviation Parts Online is a trusted distributor of aviation retractable landing gear, and we are your sourcing solution for the actuating cylinder parts, gear switch components, shock struts, bolts, and other various items that you require for your operations. To receive a competitive quote for your comparisons, send us a completed RFQ form as provided on our website and a dedicated account manager will reach out to you in 15 minutes or less to provide a personalized quote based on your individual needs. Experience the Aviation Parts Online difference today when you initiate the part procurement process.
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