| Airplane tires are a subject that I have never really | | | | strong rubber material is used. The high modus cords |
| thought about until just lately when my eight years | | | | are entwined into the rubber at a ratio of 6 for |
| old granddaughter asked what would happen if an | | | | every 28 per inch making it very dense and yet |
| airplane got a flat tire. I told her that I did not think | | | | pliable enough to give when it hits the runway at one |
| that they could. Until I looked into it, I did not know | | | | hundred and fifty miles per hour which is the speed |
| just how close to right I came. The airplane tire is an | | | | that a plane the size of a 747 must travel when it |
| amazing design of technology. It has to withstand | | | | touches down. |
| extreme centrifugal force; it must bear the weight of | | | | Since we have used the 747 as an example, we will |
| the aircraft and absorb the shock of that weight | | | | continue to describe how the landing gear plays its |
| when landing. The average Boeing 747 commercial | | | | part in protecting the wheels and placing them for |
| passenger jet weighs approximately 180 tons or | | | | landing. The landing gear is retractable on this type of |
| 360,000 lbs. That is a lot of weight to drop on a tire | | | | aircraft including the smaller wheels in the front of |
| moving over a hundred miles per hour. | | | | the plane making it a tri-touchdown point, wheeled |
| Aircraft tires have to have excellent traction while | | | | aircraft. The nose wheel assembly is exactly like the |
| maintaining support under extreme weight. However, | | | | four sets of shock absorbing main wheels except |
| unlike a car tire, an airplane tire will not experience a | | | | they are slightly smaller. There are a total of 18 |
| high volume of rotation in its lifetime. This adds to | | | | wheels counting the two nose-cone wheels, which |
| the longevity of the tire. An airplane tire will obviously | | | | are only used for weight bearing to keep the nose |
| have to have some flexibility however; the flex | | | | of the plane off the ground. They are positioned side |
| factor is not as great as on a regular vehicle tire. This | | | | by side and are separated by a small axel and cover. |
| is because airplane tires only flex on landing. | | | | There are four sets of four wheels. Two sets in a |
| Most standard airplane tires are a pneumatic tire, | | | | cluster of four each under the wings and two sets |
| which means that the tire uses air and inflates. | | | | again clustered in fours, side by side under the |
| Airplane tires use some measure or air although not | | | | fuselage. They all retract into the plane to reduce |
| for the same reason a car tire would. A car runs | | | | drag during flight. The front wheels also retract |
| pneumatic tires to help ensure a smooth ride and | | | | although they are positioned so that they do not |
| increase the mileage. Airplanes use it merely as an | | | | present themselves as drag. |
| shock absorption when touching down. They perform | | | | The majority of all landing gear work through |
| in conjunction with the systems shock absorbers. | | | | hydraulics but can be cranked up and down manually |
| The airplane tire is made up of bead cords that are | | | | in the unlikely event of hydraulic system failure. While |
| tightly wrapped with a carcass with its ends turned | | | | the smaller wheel can be physically turned left or |
| at an upwards angle that matches the body or | | | | right from the cockpit to steer the taxiing aircraft, |
| fuselage of the planes angle. There is another row of | | | | the actual "steering" is done by applying the brakes |
| corded beads that are wrapped in the opposite | | | | on one side or the other causing the plane to turn in |
| direction and these layers continue throughout the | | | | the opposite direction. |
| construction of the tire. An extremely durable and | | | | |