The tires hit the tarmac at 170 miles per hour and bear the weight of a modest office building. And they nail it—every time.

Aircraft tires are fantastic when you think about them. The typical airliner tire can handle a 38-ton load. It can meet the ground 500 times before needing a re-tread, a refresh it can take on seven times in its life. A Boeing 777 uses 14 tires, Airbus’ A380 carries 22, and the enormous Antonov An-225 demands 32. The key to their remarkable durability is maximizing the air pressure. The high-flying rubber is typically inflated to 200 psi, roughly six times what you put in an automobile tire, and the tires on an F-16 fighter are pumped to 320 psi. It’s pressurized air that’s so strong.

The tires themselves aren’t large— a Boeing 737 rides on 27×7.75 R15 rubber. In English, that means it is 27 inches in diameter, 7.75 inches wide, and wrapped around a 15-inch wheel. The sidewalls aren’t thick, and the tire’s strength lies in the cords embedded below the tread. They’re typically nylon, and more recently, a variety is known as aramid. Each layer of the casing contributes to its loadbearing and air pressure resisting capabilities. Of course, tires can fail, especially when under-inflated or overloaded. Treads can come off, and casings can blow out.

In the first moments after a plane touches down, the tires are skidding, not rolling. The aeroplane mainly drags them down the runway until their rotational velocity matches the velocity of the aircraft. That’s why they smoke upon landing and why Tires are manufactured with grooves instead of the block patterns are seen on the car’s rubber—blocks would break off. (Most tire wear comes from this moment of contact—where the rubber meets the runway.) The stoutest tires are rated for speeds of up to 288 mph.

Like everything in aviation, tires must meet specific and demanding rules—for example, a tire must withstand four times its rated pressure for at least three seconds. Each tire is carefully tested and must meet a significant safety standard before ever being put into use on a plane.