Pneumatics (from Greek πνεῦμα pneuma "wind, breath") is the branch of engineering that uses gas or compressed air.Pneumatic systems used in industry are usually powered by compressed air or compressed inert gas. A centrally located electric compressor powers cylinders, air motors, pneumatic actuator

As the design and manufacturing process of aircraft accessories become more and more mature, the system failures of a certain type of aircraft air-conditioning system due to component failures have decreased year by year.

With the gradual increase in the age of the aircraft, and the damage to the air-conditioning system caused by catkins and air pollution in certain seasons, the performance of the air-conditioning system will be attenuated or even deteriorated when the new aircraft is put into use for about two years.