APU Flashcards
What is the ECB?
Electronic Control Box- computer that monitors and controls all APU operations
What does the green AVAIL light on the START pb mean?
APU RPM is on speed
What are some conditions that will cause the APU to perform an automatic shutdown?
- fire is detected
- low oil pressure
- high oil temp
- overspeed
- EGT overtemp
- loss of overspeed protection
- inlet overheat
- DC power lost (only source is aircraft batteries and BAT OFF)
What controls an APU automatic shut down?
The ECB
Which fuel tank does the APU normally feed from?
Left fuel feed line
When would the APU fuel pump run?
Automatically when the left fuel feed line is not already pressurized
Can the APU be ran on the ground without cockpit crew supervision?
Yes, the APU is automatically self monitored and protected
What do you see when you press the APU MASTER SW pb?
- Blue ON light in pb
- APU ECAM page appears and when fully open, FLAP OPEN appears
Will the APU conduct an auto shut down due to fire in the air?
No, ground only
What is the difference between the blue ON light in the start switch and the green AVAIL light?
The blue ON light appears during the start sequence, the green AVAIL light means the APU is on speed and start sequence is complete, APU avail for electrics and air
With the APU running and supplying bleed air, how do you shut it down?
- APU BLEED pb off
- APU MASTER SW pb off
- APU will cool down (60-120 secs) and then shut down
With the APU green AVAIL light on and the EXT PWR green AVAIL light on, which system is powering the aircraft?
APU
An amber FAULT light in the APU MASTER SW pb indicates?
An APU auto shutdown has occurred
What does an amber FAULT light in the APU BLEED pb mean?
An APU bleed leak
Can you use APU bleed air inflight?
Yes
*use of APU bleed with WING anti-ice is prohibited
