APU(보조동력장치, Auxiliary Power Unit)

근거 : A321/320 FCOM GENERAL The Auxiliary Power Unit (APU) is a self-contained unit that supplies the aircraft with pneumatic and electrical power. On the ground ‐ It supplies bleed air for starting the engines and for the air conditioning system ‐ It supplies electrical power to the electrical system.

During takeoff ‐ It supplies bleed air for air conditioning (for example, when optimum aircraft performance is required). In flight ‐ It backs up the electrical system ‐ It backs up the air conditioning ‐ It can be used to start the engines.

The APU may obtain power for starting from the ..........