Understanding an Aircraft's Landing Gear System (Part 1): The Shock Absorber!

hello and welcome to jxj aviation this video would be part one on my discussion of the landing gear system here we will look at the shock absorbers on the landing gear if we look at the landing gear system on an airplane it consists of different subsystems or components which are used for different functions such as the extension and the retraction of the landing gear the brakes and the anti-skid system the steering system on the nose wheel and the one which we will focus on today would be the shock absorbers now let's see what our shock absorbers on the aircraft the shock absorbers are installed on the landing gear of the aircraft they are especially helpful during the landing of an aircraft because they will cushion the aircraft's weight when the landing gear touches the ground they are also helpful during maneuvers on the ground such as taxiing there are different types of shock absorbers installed on different aircraft we have rigid struts which were installed on some old aircraft they do not absorb any load but they directly transfer the load to the fuselage then we have steel struts which are installed on some small aircraft as shown here they can absorb some of the forces the remaining forces get transferred to the fuselage and finally we have the olymatic shock absorber which is installed in all the modern aircraft this is because they are able to absorb almost all the forces that are acting on it let's see the only pneumatic shock absorber in more detail the oleo pneumatic shock absorber installed on a landing gear consists of an outer cylinder and an inner cylinder the outer cylinder is filled with air such as nitrogen and the inner cylinder is filled with a hydraulic fluid such as oil if we take a look inside the cylinders we have an orifice which separates the air from the hydraulic fluid and we have a flow metering pin which regulates the flow of hydraulic fluid into the outer cylinder let's see what happens inside an old pneumatic shock absorber during landing to understand how it cushions the aircraft weight when it touches the ground when the landing gear touches the ground the inner cylinder moves into the outer cylinder at the same time the hydraulic fluid from the inner cylinder moves into the outer cylinder through the orifice the air inside the outer cylinder gets compressed the movement of hydraulic fluid through the orifice and the compression of air inside the outer cylinder tends to absorb the weight force of the aircraft as the speed of the aircraft reduces the compressed air starts to expand this will push the hydraulic fluid back into the inner cylinder through the orifice this tends to move the outer cylinder upward after the aircraft has landed the passengers will start boarding the cargo will be loaded and the fuel will be filled in the fuel tanks this will cause the outer cylinder to move a little downward because of the increase in weight of the aircraft when the aircraft takes off the weight force is not acting on the landing gear anymore the hydraulic fluid from the outer cylinder will move into the inner cylinder through the orifice and the air inside the outer cylinder will expand this will cause the inner cylinder to move downwards this is crucial because when the gears are retracted the shock absorber has to be extended fully on an aircraft the information from the shock absorber is sent to different systems through different detectors if the shock absorber is compressed it means that the aircraft is on the ground if the shock absorber is extended fully it means that the aircraft is in flight that's all about the shock absorber on the landing gear i'll be making different videos regarding the different subsystems of the landing gear till then thank you for watching and if you like the video please subscribe you

Channel: JxJ AVIATION

Views: 127,079

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Id: E3dtIjMEmHI

Length: 6min 26sec (386 seconds)

Published: Tue Aug 11 2020