Aircraft Landing Gear and Emergency Extension Systems
Landing gear is paramount to the operation of countless aircraft, allowing them to take-off, land, and move on runways and land-based surfaces. While permanently deployed landing gear systems are used on some aircraft, retractable systems are often the most desirable for their ability to minimize the amount of drag exerted on the plane when landing gear is not needed. In this blog, we will discuss the functionality of the retractable aircraft landing gear system, as well as emergency systems that ensure their deployment.
Depending on the aircraft and its implemented parts, landing gear systems may either be actuated and controlled through electricity or hydraulic fluid. For the operation of an electrical landing gear system, motors, gears, and jacks work together to raise and lower components as needed. A similar process can be done with hydraulic systems, albeit fluid pressure is used to overcome the forces needed for actuation instead of electricity. With both systems, deployment, retraction, and other movements are carried out by the pilot through the use of controls present on the flight deck. Located on a panel near pilots, a wheel-shaped gear switch allows for the adjustment of landing gear through various positions. To ensure that pilots know when it is safe to move landing gear and whether or not systems are already deployed, a variety of lights will be used for indication. Generally, lights will shine green when gears are down and amber lights will indicate gear being up or in transit. If the light is red, however, landing is unsafe and gear should not be deployed.
As the deployment of landing gear relies on a powering system, actuation may not be possible through normal means when there is a main power failure. As such, aircraft will implement a variety of systems that allow for the pilot to deploy landing gear through mechanical or hydraulic means for emergencies. In some aircraft, the emergency extension system will come in the form of a release handle that is located in the flight deck near the pilots. With mechanical linkages, the handle will force a gear unlock so that all systems free-fall into place through gravity. If there is more force needed to enact a gear unlock, pneumatic power may be implemented to assist the pilot.
For many smaller and lighter aircraft, hydraulic fluid may be used alongside a free-fall valve in order to achieve emergency gear extension. To achieve this, the pilots may actuate controls which results in the opening of a free-fall valve. As hydraulic fluids begin to adjust their positioning within the actuators, gear can be extended without the need of a power system. Additionally, the flow of air can also assist in the deployment of the landing gear during emergency situations once gear has been freed.
On larger aircraft, hydraulic systems are still used, though such systems are often redundant. As such, many high performance aircraft will not need to rely on emergency deployment systems as separate hydraulics may be used for deployment if the standard gears are not working. If there continues to be an issue that prevents the deployment of landing gear with a redundant hydraulic system, unlatching devices will be present to force a gear unlock for free-fall.
With the use of aircraft landing gear and emergency systems, the various procedures of land-based aircraft can be carried out with ease. When you are in need of landing gear components and other aircraft parts, ASAP NSN Hub is your sourcing solution with our unrivaled inventory and offerings. Explore our robust part catalogues today, and our team of industry experts are always on standby 24/7x365 to assist you through the purchasing process as needed. If you have any questions or would like to receive a quote on particular items, give us a call at +1-920-785-6790 or email sales@asapnsnhub.com today.
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