June 2009 Issue

Tire Tech

Your tires are the only contact you have with the ground. Heat is their enemy, and maintaining proper pressure can help prevent wear and failures.

Few pilots pay much attention to their tires. They kick them a couple of times before lighting the fire, or put air in them when they look really low, but that’s about it. That’s a little cavalier to us, considering those three (or more, if you’re lucky) small, round, rubber donuts not only support the airplane’s weight, but also supply the friction necessary to follow the yellow brick road and stop when you get to its end. As part of a project for sister publication Aviation Consumer, we recently had the opportunity to speak with industry executives about tires and tire failures, as well as a myriad of other related topics, while researching why aircraft tires fail. We found that, short of suffering a puncture, paying close attention to the airframe manufacturer’s recommended inflation pressure is your best bet to prevent tire failures. We also found that, to understand why proper inflation is key, we need to understand how these tires are made. The basic light-plane tire isn’t that much different from the ones your grandparents used on their Model T. The current standards for aircraft tires are embodied in the FAA’s Technical Standard Order (TSO) C62e, last revised in 2006 (that TSO only addresses tires; inner tube standards are set by the Society of Automotive Engineers). Instead of the radial-ply tires common on modern automobiles, your light airplane’s tires likely are a bias-ply design, where the internal fabric cords are sandwiched between two layers of rubber and laid diagonally—at 30- and 60-degree angles to the tire’s centerline—and extend from bead to bead. Additional plies are laid opposite to each other. This contrasts with a radial-ply tire, a technology widely used by larger, faster aircraft. It’s based on plies laid from bead to bead but at right angles to the tread.

To continue reading this entire article you must be a paid subscriber.

Subscribe to Aviation Safety

The monthly journal of risk management and accident prevention, is packed with useful, timely information on basic and advanced technique, accident analysis and, most important, practical articles on how you can develop the judgment that will keep you in the air and out of the NTSB's files.

Already subscribe but haven't registered for all the benefits of the website? Click here.

Subscriber Log In

Forgot your password? Click Here.