Air Brake Practice Test

Fanning the brakes in and out during long downgrades is not advisable primarily because it does not allow the brakes to effectively cool down. Continuous application of the brakes leads to heat buildup due to friction, and if fanning is performed, it limits the time the brake components have to cool between applications. When brakes overheat, it can result in brake fade, where the braking power is significantly reduced, ultimately jeopardizing safety. Proper braking technique on long downgrades involves using a consistent, moderate application of the brakes to maintain safe speeds while also allowing adequate time for the brakes to cool down, thus ensuring optimal performance and longevity of the braking system. This direct relationship between heat management and brake effectiveness emphasizes the importance of avoiding fanning in such scenarios.