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What advantage does an aeroplane fitted with an electric-pneumatic system have compared to one fitted with an engine bleed air source?
  • A
    Shorter take-off distance with reduced climb gradient.
  • B
    Longer range due to increased efficiency.
  • C
    Better de-icing capabilities.
  • D
    Cheaper and easier to use solution.

There are two types of air conditioning systems commonly used on aircraft. Air cycle air conditioning is used on most turbine-powered aircraft. It makes use of engine bleed air or APU pneumatic air during the conditioning process. Another system is electrically powered air conditioning which can be found in Boeing 787.

Some advantages of electrically driven air conditioning system:

  • Reduced fuel consumption due to a more efficient secondary power extraction, transfer, and usage.
  • Reduced maintenance costs due to elimination of the maintenance-intensive bleed system.
  • Improved reliability due to the use of modern power electronics and fewer components in the engine installation.
  • Expanded range and reduced fuel consumption due to lower overall weight.

There is no guidance on whether the initial cost of the electric-pneumatic system is cheaper than similar bleed air systems, and any engine system that reduced the take off distance would increase (not reduce) the climb gradient. The change in de-icing capabilities depends on the system. Ease of use also depends on the system. Bleed air pneumatic systems are quite easy to use so the difference will be minimal if there is one.

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