APU Flashcards
(16 cards)
What services does the APU provide and
what are they used for?
Generator supplies 28V DC. The pneumatic power is used for engine starting and to supply bleed air to the air conditioning pack of the (ECS).
How is the APU controlled and monitored?
Through a dedicated FADEC
What does pressing the APU ON/OFF button do?
It starts the ECU power-up sequence and
initiates the APU Built-In Test (BIT)
When does the START button on the APU
CONTROL panel flash green?
During the ECU BIT test
If the START button on the APU control panel illuminates amber, what does that indicate?
The APU start is inhibited
What does the START button on the APU
control panel illuminating steady green indicate?
Ready to Start
What MFW page can APU information be
seen on?
STATUS synoptic page
Which tank normally supplies fuel to the
APU?
Right tank
Is it possible to feed the APU from the left
wing tank? If so, how?
Yes, cross-feed
Can the APU supply bleed air on the ground or in flight?
Yes
On the ground, what is the primary source of pneumatic air?
APU
If the APU is the only source of electrical
power in flight, what buses can the APU
power?
All electrical loads (except for the SHED
BUSES) and also charging both batteries
Where does the APU get it’s power for starting?
BATT 2
What should be displayed on the STATUS
synoptic page if the APU oil quantity is sufficient?
Green “OK”
List the 4 conditions that will cause the APU to automatically shut down either in flight or on the ground:
Overspeed, Underspeed, ECU Internal failure, APU Bleed leak
List the conditions that will cause the APU to automatically shut down on the ground only:
APU Fire, APU EGT over temperature, APU
high oil temperature, APU low oil pressure,
APU starter not disengaged, APU fuel SOV
failure
