APU

Question 1

Can the right battery start the APU if the left is unavailable?

Answer 1

Yes

Question 2

What must be done before starting the APU in flight?

Answer 2

Perform a fire test and cycle the master switch.

Question 3

What are the cool down programs for the APU shutdown?

Answer 3

Dependent upon A/C altitude 20,000’. Above 20,000’ loads are shed, the APU runs at 100% for 60 seconds. Below loads are shed, RPM decreases 1/2% per second to 70% runs here for 60 seconds and shuts down.

Question 4

Can the APU be started with the right engine cowl open or indicating open?

Answer 4

No on the ground, yes in flight.

Question 5

Why is the APU generator switch amber?

Answer 5

It represents a non-normal situation when selected in and the APU is operating.