APU Flashcards
What does the ECB do to shut down the APU when the APU
Master Switch is selected OFF?
It generates two false signals (EGT Overheat and N overspeed)
What does the blue AVAIL light on the APU panel indicate?
The AVAIL light only indicates “APU rpm > 95%”
What can the APU supply bleed air for?
Engine start to 20,000’
What happens if the APU master switch is turned OFF prior to
turning the APU bleed switch off?
APU will run for up to 60 seconds before shutting down
APU bleed air is available up to:
20,000’
What happens if the APU ECB detects an APU fire while the
aircraft is on the ground?
APU will auto shutdown and after 10 seconds will discharge
the fire extinguisher
An APU fire is detected, when will the APU automatically
shutdown?
On the ground only
When does the APU shutdown automatically if a fire is
detected?
On the ground only
APU bleed air can be used for which of the following?
Wing Anti-ice
What does the amber FAULT light on the APU panel indicate?
APU auto shutdown occurred that was not initiated by the
APU Master Switch
Where does the APU normally get its fuel supply?
From the left fuel manifold
What can be used to start the APU on the ground, with
engines not running?
The 3 aircraft batteries
What does the APU fire detection loop arrangement consist
of?
Two loops of one element each
When is the APU capable of supplying pneumatic air to
operate both air conditioning packs?
To an altitude of 20,000 feet
When is the APU capable of supplying pneumatic air to
operate both air conditioning packs?
To an altitude of 20,000 feet
