Aircraft Electrical System

As a cabin crew or air hostess you may receive questions on aircraft electrical system fitted on the aircraft. This can come out of curiosity or the needs of the travelling passengers. The passengers may need to charge up their hand phones or computers.

If you are a cabin crew for a jetliner, the main system is ac and the secondary system is DC. The data are as follows:

A. Primary system
-115/200 volts 400 hertz 3 phases
- provided by the generator in the engines and in the auxiliary power unit.

B. The secondary system
- 28 V direct current, derived from the AC system. It has a battery for emergency.


Currently the aircraft can be fitted with special outlet to give the standard home power, which can be 240 or 115 volt.


note: APU - or auxiliary power unit is a small jet engine installed to provide the electrical power and pneumatic for the ground operation. It can also be operated in flight below a specific height. The pneumatic is used for engine start or airconditioning.

The aircraft electrical system is complex for most passengers, unless they are engineers by background. The power of the aircraft is big enough to service a small town.