An air winch is a pulling or lifting device that is powered by a pneumatic motor. There are several types of pneumatic motors, the most popular of which being vane or radial piston.
Both motors use compressed air that is directed to a set of two ports. The direction of the air on these ports causes the drums to rotate, which makes the winch move. A directional control valve commands the winch to operate in one of three positions: forward, neutral, or reverse.