Chapter 49 APU Flashcards
What is the function of the blue MAINT light?
APU oil level low, or shorting diode.
Control of the oil flow to the oil cooler, is controlled by what?
APU oil temperature control valve.
What would be an indication that the APU generator filter is clogged?
An amber fault light and protective shutdown.
What would be an indication that the APU lubrication module filter is clogged?
No indication, no shut down, just a pop out on the module.
What does the SPU (Start Power Unit) need to start the APU?
Either 28VDC or 115VAC from TX BUS 1
(Later converted to 270VDC)
At which percentage does the ECU open the APU solenoid valve open during APU start?
7%
At what percentage does the ignition unit de-energise during start?
60%
At what percentage does the starter unit de-couple?
70%
Where do you carry out an APU BITE?
Maint on the FMC
What will happen if an EGT signal is lost from one of the two EGT probes?
The APU will operate.
What is the function of the fuel flow divider?
It diverts fuel to the secondary manifold after 30% and up to 25,000ft.
The APU IGV controls the air for the?
Load compressor.
A single air inlet is shared by the load compressor and?
The power compressor (ENG COMP)
Which flight deck light will indicate an APU automatic shutdown?
Amber OVERSPEED, FAULT or LOW OIL PRESSURE
APU oil level check for quantity is done how?
By checking the sight glass on the APU or FMC
