APU

Question 1

What causes an automatic EMER. SHUTDOWN of the APU? When is this facility available?

Answer 1

• APU fire on the ground.

- Pressing the APU fire on the exterior panel.

Question 2

Why would the APU continue to run after being selected OFF?

Answer 2

If using APU bleed air, the APU keeps running for cooling period of 60sec.

Question 3

What happens if excessive EGT is sensed?

Answer 3

FAULT amber light, and a caution appears on ECAM. Followed by an automatic shutdown.

Question 4

AUTO SHUTDOWN is available during which phases of flight? And EMER SHUTDOWN (Fire)

Answer 4

1500’ – 800’

Question 5

What causes the FLAP to OPEN? What does the message FLAP OPEN mean exactly?

Answer 5

• When MASTER SW p/b is pressed.
• In green when APU air intake flap is fully open.
• In amber after 3min APU has been switched OFF.

Question 6

What happens if the START button is pressed immediately after the MASTER button is pressed?

Answer 6

• Green light comes on when N is >99.5% or 2sec after N reaches 95%
• APU can now be used for electrics and/or bleed

Question 7

What is the Maximum altitude for APU start?

Answer 7

• 41,000’ by electrical power
• 25,000’ by battery only
• 14,500’ on the ground

Question 8

What are the altitude limitations for the use of APU bleed & packs?

Answer 8

2 packs: 15,000’

1 pack: 22,500’

Question 9

What would you do if the SD showed LO OIL LVL?

Answer 9

• Refill the oil
• Low APU oil when the aircraft is on the ground, and the APU is not running.
• The APU may be started ad operated even if the LOW OIL LEVEL ECAM advisory is displayed.
• Maintenance action is required within next 10hrs of APU operation.

Question 10

What is the APU start limitation?

Answer 10

After 3 starter motor duty cycles, wait 60min before attempting 3 more cycles.