Wednesday, November 24, 2010

How often do planes change tires? It seems like they waste their tires with every landing. Is it true?

When i see a plane landing, planes tires are always giving out a smoke like its all wasted. Do they change tires soon? How long does a set of tyre can hold up on a commercial jet plane?

And lastly, how much does it cost to buy a single plane tyre? :)How often do planes change tires? It seems like they waste their tires with every landing. Is it true?Smoke has little to do with it. There is always wear after any landing and alot of it has to do with weight, length of runway, and pilot skill. I worked on KC-10s and DC-10. Tires would sometime last 20-30 landings or more. But if there are heavy loads (cargo, passengers) then the wear is accelerated. Tires get changed long before they are ruined. There is a layer of ply approx: 9/32 under the tread groove. When you hit it, you change the tire. This allows the tire to be retreaded and you pay for a retreaded tire instead of a new one. Large tire such as those cost nearly 10,000 dollars. They a split wheels and very heavy. Testing of anything by the FAA jacks the price up. Actually, I changed more tires due to cuts than wear. Proper inflation, I should mention, is the best way to save tire, prolong the use, and save lives. Aircraft have crashed and people died due to under inflated tires!How often do planes change tires? It seems like they waste their tires with every landing. Is it true?Aircraft tires are designed to withstand extremely heavy loads for short durations. The number of tires required for aircraft increases with the weight of the plane (because the weight of the airplane is distributed better). Aircraft tire tread patterns are designed to facilitate stability in high crosswind conditions, to channel water away to prevent hydroplaning, and for braking effect. Aircraft tires are usually inflated with nitrogen or helium in order to minimize expansion and contraction from extreme changes in ambient temperature and pressure experienced during flight. Dry nitrogen expands at the same rate as other dry atmospheric gases, but common compressed air sources may contain moisture, which increases the expansion rate with temperature. Aircraft tires generally operate at high pressures, up to 200 psi (13.8 bar) for airliners, and even higher for business jets.



Aircraft tires also include heat fuses, designed to melt at a certain temperature. Tires often overheat if maximum braking is applied during a rejected takeoff or an emergency landing. The fuses provide a safer failure mode that prevents tire explosions by deflating in a controlled manner, thus minimizing damage to aircraft and objects in the surrounding environment.



The main purpose of requiring that an inert gas, such as nitrogen, be used instead of air, for inflation of tires on certain transport category airplanes is prompted by at least three cases in which the oxygen in air-filled tires combined with volatile gases given off by a severely overheated tire and exploded upon reaching autoignition temperature. The use of an inert gas for tire inflation will eliminate the possibility of a tire explosion

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The service life and price of aviation tires is depended upon the type and weight of an aircraft and the size of the tire.

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For what it's worth the space shuttle tires are each only used one time and cost $70,000.00 a piece.

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