Question

The tires of airplanes (at least the big ones) are inflated by nitrogen (instead of air). Why is this done?

Asked by: Fernand Zwickl

Answer

Air has a certain moisture content and it is generally very hard to remove this moisture. If an airplane tires were filled with air, at the flight altitude ice would form inside the tires since the temp up there is about -30 degrees F. Landing with a chunk of ice in the tire would make it out of balance and change the tire pressure. Tires would probably burst.

On the other hand, nitrogen doesn't form a liquid till -173C and pure nitrogen has almost no moisture.

In addition, consider if the brakes overheat and cause a fire. The nitrogen will not burn, but air has oxygen which will feed the fire. Jet airline tires are fused. When the fuse is heated it deflates the tire so they don't explode.

Answered by: Scott Grasmick, B.A., Health Physicist, Bremerton, WA



The huge tires on aircraft are expensive, and difficult to mount and dismount. They are also subjected to tremendous forces on landing when they must accelerate very quickly. The friction on touch-down creates great heat within the tires and produces very high stresses in the walls of the carcass.

Therefore, every effort is made to reduce or eliminate the deterioration caused over time by oxidation.

Since normal atmospheric air is approximately 20% oxygen, the tires are inflated with 100% nitrogen - a relatively inert gas.

Answered by: Dick Brill, B.S.

Search

Loading


Support Discovery Capsule - Anton's new project on Kickstarter.



Science Quote

'The most precious things in life are not those one gets for money.'

Albert Einstein
(1879-1955)
Science Sidebar | Science Education Articles
Cool Summer Science Projects

Why not make science a part of your family’s summer? Perhaps you can set aside one day a week for outdoor projects—maybe Mad Scientist Monday or Scientific Saturday? Here are a few ideas to help get you started. Continue reading ...

10 Ways to Keep Your Kids Interested In Science

Young children are natural scientists: they ask questions, pick up sticks and bugs outside, and are curious about the world around them. But as they get a bit older, many kids gradually lose their interest in science. They might see it as just another task at school, something that doesn't apply to their lives. Of course nothing could be further from the truth, so here are ten ways you can remind your kids that science is everywhere. Most of these are fun for adults, too! Continue reading ...

Top Selling

Here are our physics & astronomy bestsellers:
Space Wonder Gyroscope
KonusScience 5 Way Microscope Kit
12 inch Galileo Thermometer
Solar Radiometer
Enviro Battery 4M Kit
Wood Grain Newtons Cradle
Brush Robot 4M Kit
Tin Can Robot 4M Kit
Electric Plane Launcher 4M Kit
Cherry Wood Levitron

Sponsors

USC University of Southern California Dornsife College Physics and Astronomy Department McMaster University Physics and Astronomy Department