Are Airplane Tires Solid? What Are They Filled With?

When it comes to airplane tires, a common misconception is that they are solid. However, the reality is quite different. Airplane tires are typically pneumatic, meaning they are filled with air, just like the tires on your car. These tires are designed to withstand the high pressures and loads experienced during takeoff, landing, and taxiing, ensuring safe and efficient operations.

The High-Pressured Reality

The air pressure in airplane tires is significantly higher than in regular car tires, usually ranging from about 30 to 50 psi (pounds per square inch) for commercial aircraft. This high pressure is crucial in supporting the weight of the aircraft and providing the necessary cushioning during landings.

Special Cases and Requirements

In some specialized applications, such as with certain military or cargo aircraft, tires may be filled with foam or other materials to prevent punctures and provide additional support. However, the vast majority of commercial aircraft tires are air-filled, with regular air being commonly used on smaller aircraft like single-engine Cessnas. For most commercial planes, however, nitrogen is the preferred gas for filling.

Nitrogen's Role - Nitrogen is used in many commercial aircraft because it resists shrinking and expanding from temperature changes. This maintains consistent pressure, reducing the risk of issues such as blowouts due to flexion or overinflation. The use of nitrogen is particularly beneficial in heavy aircraft weighing more than 300,000 lbs (136 tonnes) due to the increased risk of adverse effects from temperature-induced pressure fluctuations.

Effects of Inaccurate Inflation

Proper tire inflation is critical for safety and efficiency. Coming in with air pressure that is too low can cause a blowout from flexion upon landing. Similarly, air pressure that is too high may also cause a blowout, even under normal weight conditions. This can have a more significant impact on heavier aircraft. Overinflated tires can also reduce friction, which means that aircraft may not stop within regular distances, especially for heavier aircraft.

Stopping and Safety

Stopping is, in many ways, more critical than landing. While the speed and weight during landing are managed within safe limits for small aircraft, even under worst-case conditions, the aircraft takes far less runway to land. The tires used in small aircraft are rated to handle much higher speeds and loads than the aircraft can achieve during takeoff.

However, this does not mean that nitrogen use in small aircraft is not beneficial. Nitrogen or air should be regularly checked and frequently serviced to ensure optimal performance. The choice of filling gas and correct inflation are essential cues in ensuring the safety and reliability of an aircraft’s operations.

Conclusion

Airplane tires are not solid but are primarily pneumatic and filled with air (or nitrogen in many cases). The high-pressure design and use of suitable gases like nitrogen ensure that these tires can withstand the unique demands of aviation. Proper tire maintenance and inflation are crucial for the safe operation of any aircraft, making regular checks an essential part of the flight preparation routine.