E190 - Auxiliary power unit Flashcards
What power does the APU generator supply ?
115 V, 40 kVA
How is fuel supplied to the APU:
- When only DC power is available ?
- If AC power is available ?
- If the engines are running ?
- DC fuel pump
- AC fuel pump
- Ejector fuel pumps
Until which altitude is the APU able to supply:- Bleed air for airconditioning en pressurization ?- Bleed air for engine starting ?- Electrical AC power ?
- 15,000 ft- 21,000 ft- 33,000 ft
What is the maximum altitude for an APU start ?
30,000 ft
What happens when you rotate the APU master switch to ON ?
- The FADEC is powered
- APU fuel shutoff valve opens
To avoid an unsuccessful APU attempt start, how long should you wait (recommended) after EICAS is on ?
30 seconds
After an APU start, when is electrical and pneumatic loading available ?
3 sec after 95% APU speed
What is the sequence of an APU start ?
- Ignition: at 6% RPM (7-17% in flight)
- Fuel: after 0,5 s
- Starter cutout : at 50% RPM
What happens when you rotate the APU master switch to OFF ?
A normal APU shutdown is initiated (monitored by the FADEC). APU SHUTTING DOWN message is displayed.Pneumatic power is removed immediately, AC power is removed at the end of the 2 min cooldown cycle.
What happens if you rotate the APU master switch from OFF to ON during an APU shutdown ?
The shutdown is cancelled.
What happens if you press the APU EMER STOP pushbutton ?
The APU fuel shutoff valve is closed.The APU is shutdown without a cooling period.
Against which conditions is the APU protected by the FADEC in flight ? (and an automatic shutdown is initiated)
- Overspeed- Underspeed- FADEC critical fault
Against which conditions is the APU protected by the FADEC on ground ? (and an automatic shutdown is initiated)
- Overspeed- Underspeed- FADEC critical fault- APU fire- APU high EGT- APU high oil temperature- APU low oil pressure- Sensor fail
When is the APU ALTITUDE EXCEED msg displayed ?
If the airplane is flying above 33,500 ft with the APU running.
