49 airbourne auxilary power Flashcards
1
Q
what is an APU
A
a turboshaft engine to provide secondary power sources.
2
Q
apu purpose
A
- ground power where no external connections available
- use its pneumatic power to start engines
3
Q
what loads can the APU power?
A
electrical (has a 110VAC generator)
pneumatic (from compressed air)
4
Q
what does nonessential APU do on ground?
A
- start engines
- aircon bleed air
- supply elec generator
5
Q
what does nonessential APU do in flight?
A
- aircon bleed ait
- supply elec generator
6
Q
how does the APU start
A
bat bus turns DC electrical starter motor.
to high enough rpm for self sustaining combustion
