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A possible pneumatic source in a single engine piston aircraft is:
  • A
  • B
    Bleed air.
  • C
    Compressor pump.
  • D
    Ram air turbine.

Learning Objective Describe the following means of supplying air for the pneumatic systems for piston-engine aircraft: compressor; vacuum pump.

In piston engine aircraft, different sources of air supply can be used, such as compressors, blowers or vacuum pumps. Those devices are driven by small electrical motors or directly by the engine and provide air for some instruments, de-icing and cabin. Compressors are able to handle more air while blowers and vacuum systems are used for lower demands.

Ram air turbine may be used on larger aircraft as a backup hydraulic power source.
Bleed air provides air supply for a gas turbine engine.
Turbocharger is not necessarily running all the time and therefore would be of no use as air

Note: Superchargers can be used to provide pneumatic pressure, as they are effectively the same thing as an air compressor, just one that is usually used to provide extra Manifold Pressure to the engine intake air. This is why some textbooks and questions do refer to them as possible pneumatic pressure sources, but compressor pump is much more correct than turbocharger here, as turbochargers are not always working in an engine.

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