APU Flashcards
If more than 1000 lb of fuel have been loaded in the center tank and you need to run the apu, which fuel pump should you turn on so you dont get an imbalance prior to takeoff?
Left center
If no fuel have been loaded in the center tank and you need to run the apu, which fuel pump should you turn on?
Left forward fuel pump
Run the APU for how many minute before using it bleed air source?
2 minutes
If APU MAINT Light is illuminated, what should you do?
If APU MAINT Light is illuminated, only operate the APU if
needed. Make AML entry.
How many minutes should you wait after apu shutdown and apu gen bus off light extinguishes before turning the battery switch off?
2 or 3 minutes depending on aircraft
What happens to the apu if you turn off the battery?
Apu shuts down
What control module controls apu operation?
ECU - Electronic Control Unit
Where does the apu get fuel from?
Left fuel manifold
With no power on the airplane, how does fuel get to the apu for the initial start?
Suction feeds from the left fuel tank
Does the apu have auto shutdown features?
Yes
On the ground, what all does the apu auto shutdown for?
EGT exceedance High oil temprature Low oil pressure Failure to start Failure to accelerate APU fire
The APU door has how many positions?
3
Closed
Open ground
Open air
What happens if you turn the battery switch off while the apu is running?
Apu shuts down
Where do we get electrical power to start the apu if AC power is not available?
Airplane battery
Where do we get electrical power to start the apu if AC power is available?
No 1 Transfer bus