When will the APU Shut down autmatically on the ground?
On the ground for a MajorFault.
Example Fire within 10 sec, High temp, Low oil pressure.
in flight a critical fault
ex. overspeed underspeed
What controls the APU
a dedicated FADEC for controlling fuel for starting and shutdown.
Where does the APU get its Fuel from?
The right tank normally
left tank through crossfeed valve.
What battery does the APU use for start?
The #2 battery. and is connect to the central bus.
what happens when you move the APU selector to OFF
Deenergizes the FADEC, closes the APU fuel shutoff valve, turns off indications and alarms.
When will the APU shut down if the control system fails
At what point is the APU ready to take on electrics and pneumatics?
95% + 7 sec
Max altitude for starting APU is ?
Max altitidue for operation is ?
Minimun battery temp for APU start is ?
When does the Fule shutoff valve close?
APU Master knob positioned to OFF
Pressing the APU Fuel shutoff button pressing the APU fire extinguishing button
Automatically through the APU fire detection system in case of APU Fire on the ground.
When APU FIRE EXTG is pressed.