pneumatics Flashcards
What systems are generally powered by pneumatics?
Air conditioning, pressurisation, hydraulic reservoir pressure, and de-icing.
At what stage is the bleed air extracted from the engine?
Dependent on the RPM. At medium to high RPM, air is usually extracted from the low pressure (LP) or Intermediate Pressure (IP) stages, but at low RPM where the pressure may not be sufficient, it may come from the high pressure (HP).
How does the pneumatic system know which stage of the compressor to extract the air?
Pressure regulator, check valves, and if pressure insufficient, a butterfly (selector) valve rotates.
In a pneumatic system, what is the purpose of an isolating valve?
Each engine will supply pneumatic power for it’s own aircon pack, engine/wing deicing etc… however it is all shared through a manifold. The isolating valve will stop this being shared.
What should the crew do in the event of a bleed air leak?
Isolate the system, and turn it off to prevent structural damage (rupturing the lines).
