APU Flashcards
How is fuel fed to the APU with no AC power available on the aircraft?
The DC Fuel Pump located in the right main tank
What controls the operation of the APU Bleed Valve when the APU BLEED push button is
pushed in
Air Management System logic
What maximum altitude is the APU able to supply Electrical Power and Bleed Air?
33,000 ft for Electrical Power and 15,000 ft for Air Conditioning and Pressurization
The maximum altitude for APU start is?
30,000 ft
Rotating the APU MASTER switch from ON to OFF commands APU FADEC to begin the
shutdown sequence, initiating a one-minute cool down period. What is true concerning the
shutdown sequence?
Turning the APU selector back to ON during the shutdown sequence cancels the shutdown
What happens when the APU Emergency Stop Button is pushed?
The APU Fuel Shut Off Valve closes and the APU shuts down without a one-minute cool
down period
he FADEC will shut down the APU in flight for:
Overspeed
What occurs if the APU is running and the aircraft is at or above 33,500 ft?
The APU will automatically shut down
If the APU does not reach proper speed or acceleration rate within the starting cycle time, the
APU will:
Automatically shut down
On which display would the crew find information regarding the operational status of the APU?
The EICAS
The APU is automatically monitored and controlled through:
The FADEC
During pre-flight what must the crew ensure prior to starting the APU?
That a Fire Extinguisher check is accomplished
During pre-flight what caution must be adhered to by the flight crew while on the flight deck with
the APU running?
Do not leave the flight deck unattended except to perform required duties in the vicinity of
the aircraft
What is the first step in the flow for the APU start procedure if Conditioned Air is connected?
(The system fire test was previously conducted)?
BLEED APU …………………………………. Push Out
How long should a crew member wait after placing the APU CONTROL MASTER to ON before
placing the switch to START?
5 seconds
