You’ve already had the chance to see many interesting facts about tires on FreeGameGuide, including the amount of work it takes to manufacture a compound. In addition, he learned that there are tires for cars equipped with 5G technology, compounds that do not puncture and even made with rice husks. Now, it’s time to learn some fun facts about another type of tire: the airplane tire.
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To start the conversation, let’s say that, as in the case of tires for more traditional vehicles, such as cars, motorcycles and trucks, aircraft tires can be found in two different models: with or without an inner tube. In the second case, they are coated with a thicker, less permeable rubber that replaces the chamber’s function.
In addition, the aircraft tire is also composed of several layers, all with functions similar to those found in the compounds of other vehicles. Are they:
- Wall (or side)
How long does an airplane tire last?
The differences between car and airplane tires are becoming evident when the subject in question is durability. If in traditional vehicles composites can run safely for up to 60,000 kilometers (or 500,000, as promised by those made from rice husks), in airplanes the scenario is quite different.
While a car owner can go up to 5 years without having to change the compounds, anyone who needs to keep an airplane always in order is obliged to change the tire, on average, every 20 days. That’s what Fabio Pinto, manager of Gol Aerotech’s component workshops, revealed in a recent interview with CNN Brasil.
According to the person responsible for maintaining the compounds used in the aircraft of one of the main airlines in Brazil, the measurement of the durability of the plane tire is carried out by the number of landings. He revealed that the compounds are reassessed after each landing, and that the tire usually performs, on average, 200 for those positioned on the main landing gear and 120 for those below the ‘nose’.
Retreading a tire is a valid option
The prices of the tires that equip the main commercial jets in the world are quite high, and can reach US$ 2,500 (more than R$ 12,500, in the current conversion). There is, however, a much more affordable option that is adopted by airlines to save money, without neglecting safety.
According to Fabio Pinto, a retreaded tire costs about 30% of a new compound for aircraft. Because of this, the company has the habit of carrying out the retreading process at least 5 times on the tires used in the main landing gear and 11 times on the compounds that are in the landing gear below the nose.
How many tires does an airplane have?
Now that you know the average price of an airplane tire, it’s easy to find out how much each company spends just on these compounds to always leave the aircraft in ideal safety conditions. And the cost varies, as each plane has a different number of wheels and tires.
The number of wheels and tires on an airplane is determined by the weight and size of the aircraft. The Antonov An-225, destroyed in the war between Russia and Ukraine, was equipped with 32 tires. An Airbus A380, considered the largest passenger plane in the world, needs 22 tires to support its weight of almost 580 tons. With each game exchange, therefore, approximately US$ 55,000 is spent.
Planes such as the Boeing 747 have four sets of landing gear, two on each side of the aircraft, each with four wheels, in addition to one with two wheels under the nose. In total, the Boeing 747s have 18 wheels and tires each.
Check below other planes and how many tires they have:
Boeing 712,727 or 737:6
Boeing 777: 14
Gulfstream G650: 6
Learjet 70/75: 5
Embraer Phenom 100: 3
Airplane tire size
As with other vehicles, the plane tire also has different sizes and measurements, and the use depends precisely on the dimensions of the aircraft it will wear.
The size of each tire is marked on the sides of the compound and is measured in inches by default. The larger the plane, the more inches the tires will need to support the total gross weight and distribute correctly. Tires for smaller planes start at 5 or 6 inches, but the so-called ‘Type 1’, used on most commercial aircraft, that is, large ones, are 27 inches.
A Boeing 747, in turn, uses H49x19.0-20 tires. This ‘equation’ means that the tires on this type of plane have a diameter of 49 inches. An Airbus A320, on the other hand, has 30 x 8.8R15 tires, which indicate a size of 29 inches. The Airbus A380 uses the largest commercial airliner tire in the world, measuring 56 inches in diameter and 21 inches wide.
What gas is inside an airplane tire?
Have you ever stopped to think what’s inside an airplane tire? If you answered “air, of course”, know that you were right… at least in parts. An airplane tire cannot be inflated with the traditional compressed air used in cars, motorcycles and other vehicles. Why? For security.
The gas used to calibrate an airplane tire is nitrogen. After all, it is an inert gas, that is, it maintains its composition regardless of the temperature or pressure to which it is subjected. And as planes face extreme temperatures, both hot and cold, the use of ‘normal’ compressed air is not indicated, as it could overheat and explode on landing, for example.
The opposite, that is, exposing a tire inflated with traditional compressed air to a very low temperature (it reaches -30ºC at high altitudes), would also be problematic, as the tire could compress and, with that, even fall of the wheels during flight.
How to change a tire on a commercial plane?
Now that you already know a lot of fun facts about an airplane tire, how about one last one, just to complete the material? Do you know how to change tires on a commercial plane? Not? In an interview for the Superinteressante website, Renato Gengo, an aircraft mechanic, explained.
According to the specialist, the process is very similar to changing the tire of a common car, but it demands a much more complex care. According to him, it is necessary to isolate the area, chock the wheels and close the doors to prevent the fuselage from bending when the plane is lifted.
Fabio Pinto, components manager at Gol Aerotech, also addressed the subject to CNN Brasil, and added an explanation of what it’s like to change a tire on a commercial plane. The key point of the process is the hydraulic jack, which, for obvious reasons, needs to be extremely resistant.
Pinto explained that the jack is placed under the main landing gear and, after the aircraft is raised, a single nut, centered on the axle, is removed so that the tire can be removed. Next, the other one is installed, the nut tightened and the hydraulic jack removed. The entire procedure takes around 20 minutes.