Aircraft Brake Wear and Temperature Indicators
Aircraft brakes work hard at stopping a landing aircraft. Over time, they wear. The rate of wear is dependent on several factors such as length of runway, aircraft speed, and current temperature. We all know the brakes are going to need replacement at some point, however determining when can sometimes be a guessing game.
Every tyre brake unit has the wear indicator pin and it is visually inspected before and after flight (Some airline companies note the length of these pins). Brake overhaul is required when the brake wears such that the pin is no longer protrudes from the bushing.
Brake temperature indicators are intended to give the pilots an indication of the temperature in each wheel assembly. While each aircraft type will have its own specific limitations for items such as maximum indicated temperature for initiating takeoff, comparison of the brake temperature indications can give an overall indication of the “health” of the braking system. For example, inappropriately high or low temperatures on a given wheel can indicate the potential of a dragging or an inoperative brake respectively. Similarly, increasing brake temperatures after takeoff could be indicative of a tyre failure which has resulted in a wheelwell fire.