Subtask 10.1.6 Operate APU

Question 1

Recite APU starter limitations.

Answer 1

Attempts 1 & 2…………60s OFF
Attempts 3,4,5………….5m OFF

Question 2

Recite MAX APU altitudes.

Answer 2

APU continuous use = 33,000’
APU electrical use = 33,000’
APU start= 30,000’
APU engine start= 21,000’
APU bleed use= 15,000

Question 3

According to the SOPM, when should the APU be turned on?

Answer 3

The APU is started approximately 10 minutes prior to pushback, unless required for passenger comfort

Question 4

On DC power only, what is required to start the APU?

Answer 4

The batteries.

Question 5

When ECS is configured to ON, what needs to be done to the APU during takeoff?

Answer 5

APU OFF

Question 6

When ECS is configured to OFF, what needs to be done to the APU during takeoff?

Answer 6

APU ON

Question 7

For what reasons will the APU automatically shut down on the ground? In-flight?

Answer 7

On-ground (UFOSHELF)

Underspeed
FADEC critical fault
Overspeed
Sensor fail
High oil temp (APU)
EGT Overtempt (APU)
Low oil pressure (APU)
Fire (APU)

In-flight (UFO)

Underspeed
FADEC critical fault
Overspeed

Question 8

Describe the APU shutdown process.

Answer 8

APU FADEC controls and monitors the normal shutdown sequence. During normal shutdown, the APU pneumatic power is removed immediately and the electrical power is removed at the end of a (1) minute cool down period. The cooldown period is followed by a spooldown period. The EICAS message APU SHUTTING DOWN disappears at the end of the spooldown period.
NOTE: Wait until APU indicates OFF on EICAS. Wait an additional 80 seconds until APU FUEL SOV CLOSED message is momentarily displayed on EICAS before turning batteries OFF.