Powerplant - Auxiliary Power Units Flashcards
1
Q
An APU on modern transport aircraft performs what functions?
A
To supply ground electrical and pneumatic power
2
Q
What are the major components of an APU?
A
A small turbine powered powerplant generator and provisions for providing pneumatic power
3
Q
What is used to start an APU?
A
Electrical (battery) or hydraulic power
4
Q
Does the APU use the same fuel supply as the main engines?
A
Normally, Yes
5
Q
What controls the speed of an APU?
A
The governor on the speed control
6
Q
What is APU pneumatic power used for?
A
Air conditioning, engine starting, troubleshooting and anti-icing
7
Q
Abrupt shutdown of an APU, without a cooldown period, could cause what?
A
Thermal shock
8
Q
How long is a typical cool down period?
A
3 minutes
