APU

Question 1

The APU operates at a constant speed to meet the aircraft’s electrical demand. (T/F)

Answer 1

True

Question 2

While the APU is operating, what will happen if the Battery (BAT) switch is moved to OFF?

Answer 2

The APU will shut down because power is lost to the ECU.

Question 3

What happens as a result of selecting the APU switch to START?

Answer 3

1. The fuel shut off valve opens
2. The LOW OIL PRESSURE light illuminates.
3. The air inlet door opens.

Question 4

The normal method of shutting down the APU is?

Answer 4

Selecting the APU switch to OFF.

Question 5

The ___ controls and monitors the APU?

Answer 5

Electronic Control Unit (ECU)

Question 6

What does an amber FAULT light mean? Located under the APU GEN Switches?

Answer 6

The APU has auto shutdown due to a fault detected by the ECU.

Question 7

Air for the APU compartment cooling is drawn in from which area?

Answer 7

Inlet above APU exhaust. Low pressure area draws in air for cooling.

Question 8

Fuel can be supplied to the APU by which of 2 sources?

Answer 8

1. Suction feed from the No. 1 tank.
2. AC powered fuel pump.

Question 9

In the event of a fire, the APU can be immediately shut down by:

Answer 9

1. Pulling the APU Fire Warning switch.
2. Pulling the APU Fire Control Handle on the APU Ground Control Panel.