The term “air brake” actually refers to two very different braking mechanisms. The first type is the one you likely associate with heavy transportation. It is used by railroad trains, trucks, and buses. The system operates using a piston. This piston is driven by compressed air. The air comes from reservoirs connected to brake cylinders. When pressure in the brake pipe drops, the system automatically admits air into the cylinder. This action engages the brakes. The first practical air brake for railroads was invented by George Westinghouse in the 1860s.
Aircraft and Race Car Braking Systems
The term is also used to describe the braking system used by aircraft and race cars. This specific type of brake is quite different from the train system. It consists of a flap or surface. This flap can be mechanically projected into the airstream. The goal is to increase the resistance of the vehicle to air. This added resistance helps lower the speed of the vehicle quickly.
