APU Flashcards
1
Q
APU FAULT light indicates? (2)
A
APU shutdown due to a fault or
Shutoff valve not in commanded position
2
Q
Power to start the APU is supplied by?
A
Both the aircraft and APU batteries.
APU battery supplies power to the starter, the air inlet door and the APU control circuitry.
Aircraft battery supplies power for fire protection, APU fuel valve and DC fuel pump
3
Q
What is the time delay before APU shutdown?
A
If the APU bleed valve is closed for more than 60s, NO delay.
time delay is variable from 0 to 120s, nominally set to 60s.
4
Q
the FAULT light comes on briefly during APU start. What does it indicates?
A
The APU fuel valve is not in the commanded position.
5
Q
During APU start, when does the electric starter engage?
A
When the APU inlet door is fully open
