Airplanes may be huge, but have you ever noticed how small their tires look in comparison?
If you’ve ever looked out an airport’s window as a plane lands or when it has landed, you may have been surprised at just how small the tires are compared to the plane.
The reason airplane tires are small is because they need to be small to be effective.
Smaller tires are better designed for landing and taking off because they can easily withstand the high temperatures and pressures involved during landing.
Smaller tires also reduce an aircraft’s weight.
Airplane Tires Vary in Size
Airplane tires are small relative to the size of aircraft, though generally the bigger the aircraft is, the bigger its tires will be.
A majority of commercial plane’s tires are only 27 inches in diameter.
Smaller aircraft have smaller tires at 15 inches in diameter.
The first types of airplane tires were titled the ‘Type 1’, and they had diameters of 27 inches.
Modern general airplane tires are known as the ‘Type 3’ and include more diverse sizes like the 5.00-5 and 6.00-6.
These numbers refer to the tire’s width and the diameter of the rim ledge. So a 5.00-5 has a width of 5 inches and is used for a wheel with 5 inches in diameter.
Private Planes Tire Size
- Beechcraft King Air 350
The King Air uses 8.50-10 size tires. This means that this plane’s tires have a 26 inch diameter when measured from the outside.
- Cessna Hawk XP
The Cessna Hawk XP uses 6.00-6 with 4 PLY tires. These tires have a diameter of 17.5 inches when measured from the outside.
Commercial Airliners Tire Size
- Boeing 747
The Boeing 747 uses H49x19.0–20 tires. These tires have a 49-inch diameter when measured from the outside.
- Airbus A320
The Airbus A320 uses 30×8.8R15 tires. These tires have a diameter of 29.5 inches when measured from the outside.
Military Planes Tire Size
The F-15 uses 34.5×9.75–18 tires. This means the F-15’s tires have a diameter of 34.5 inches when measured from outside.
The C-130 uses tires of a 56×20/24PR size. This means the C-130 tires have a diameter of 55.5 inches when measured from outside.
Why Airplane Tires Are So Small
An airplane tire’s footprint, which is the amount of surface area of the tire that touches the ground, times air pressure, must match an aircraft’s weight to support an aircraft.
Since air pressure is generally large, airplane tires need to be small.
Large tires would not benefit aircraft. Instead, having larger tires would result in airplanes not being able to land properly.
Larger tires increase an aircraft’s load and could damage runways. Additionally, larger tires would make a plane bounce more when landing.
In view of these considerations, it makes sense to keep airplane tires as small as possible.
The Biggest Tire Size on a Plane
The Airbus A380 has the largest commercial plane tire size in the world at 56 inches in diameter and 21 inches in width.
The largest aircraft tires ever made were for the B-36 Bomber in the 1950s.
These tires were over 5 feet in width and 10 feet in diameter.
4 Manufacturers Dominate the Airplane Tire Market
The airplane tire manufacturing industry is dominated by 4 firms that control 85% of the global market. These firms are:
- Goodyear (United States)
- Michelin (France)
- Dunlop Aircraft tires (United Kingdom)
- Bridgestone (Japan)
The remaining 15% of the global airplane tire market is mostly made up by small manufacturers in other countries like China.
Some of these other companies include Guilin lanyu Aircraft tire Development Co, which is a subsidiary of ChemChina.
Do Planes, Helicopters or Trucks Have Bigger Tires?
Many helicopters and planes have the same tire size. This is especially true for general aviation aircraft.
Helicopter tires are also designed similarly to airplane tires since helicopter tires face the same pressures and temperatures as airplane tires.
But, trucks have larger tires than both helicopters and airplanes.
Truck tire sizes vary widely, but the average truck will have a larger tire than the average airplane or helicopter.
Related: Do Helicopters Have Wheels?
Airplane Tires Eventually Need Replacing
The average airplane tires can withstand 500 landings before requiring repair.
Typically, after 500 landings, the tire’s top layer is peeled off and needs to be replaced with new treading.
Unless the rest of the tire also suffers damage, normally just the tread will be replaced.
Related: How Long Do Airplane Tires Last?
Why Plane Tires Don’t Explode on Landing
Airplane tires are made of proprietary rubber compounds, aluminum steel reinforcements and nylon and aramid fabrics.
These materials ensure that the tire has sufficient strength to support a plane.
Airplane tires are also inflated with nitrogen to prevent explosions during impact.
Nitrogen is an inert gas, so the high pressure and temperature changes during landing don’t affect it as much as they do regular air-filled tires.
Planes Need Their Tires Changed Too
Depending on numerous factors, a plane’s tires could be changed anywhere between 120 to 400 landings.
Airplane tires need to withstand both extreme temperatures and high pressures.
Long-range airplanes like the Boeing 747 also complete thousands of takeoffs and landing over their course of operations, so most aircraft will frequently need their tires changed.
Longer-range aircraft tend to have more tires changed over the course of their operation than shorter range aircraft.
In conclusion, airplane tires are relatively small compared to the planes they’re fitted on. Airplane tires are small because they need to be. Smaller tires have reduced surface area contact with the ground and reduce aircraft’s weight.