PNEUMATIC SYSTEM AS A SOURCE OF POWER

1.3 PNEUMATIC SYSTEM AS A SOURCE OF POWER

Pneumatic system, as a power source, is generally a backup to the hydraulic power system for the operation of many essential and non-essential services.

In modern jet airliner, pneumatic system furnishes many other services in addition to the back up service to the hydraulic powering. Some examples of those operations are:

v     Extension and retraction of landing gear

v     Application of wheel brakes

v     Actuation of flight control surfaces

v     Opening and closing of freight doors.

As a power source, pneumatic system has both advantages and as well as disadvantages as compared to hydraulic power system.

Advantages:

v     System is simple requiring no return lines as the return pressure is exhausted to the atmosphere.

v     It saves weight. Smaller cross-section pipes can be used. Hydraulic fluid is heavier than compressed air.

v     Cleanliness is achieved by the use of compressed air. 

v     Fire-hazards are completely eliminated.

v     It has high fluidity and low viscosity. 

v     Ease of maintenance and economical.

Disadvantages:

v     It is unsuitable for large capacity components.

v     Leakage cannot be easily detected.

v     Pipeline and component failure can be dangerous.