Boeing B777 – APU - SmartCockpit - Airline training guides, Aviation, Operations, Safety

Cooldown period when the APU is shut down after the APU LIMIT message is displayed.

60 seconds.

90 seconds

120 seconds.

There is no cool down period.

Correct! Wrong!

When the APU air inlet door reaches the full open position the starter engages. After the APU reaches the proper speed, ignition and fuel are provided. When the APU reaches approximately ______, the starter disengages and ignition is turned off.

70 percent.

50 percent.

300°C.

400°C.

Correct! Wrong!

For the following faults, the APU continues to operate and the EICAS message APU LIMIT displays:

High EGT, overspeed, high oil temperature and low oil pressure.

High EGT and low oil pressure.

High EGT, overspeed, underspeed, high oil temperature and low oil pressure.

High EGT, high oil temperature and low oil pressure.

Correct! Wrong!

If AC power is not available or no AC pump pressurizes the left fuel manifold, the DC pump in the right main tank provides APU fuel.

True.

False.

Correct! Wrong!

The DC pump in the left main tank provides APU fuel.

Rotating the APU selector to OFF begins the shutdown cycle by closing the APU bleed air valve. The APU continues running for a cooldown period. The EICAS memo message APU COOLDOWN is displayed during the cooldown period. When the cooldown period finishes, the APU shuts down.

True.

False.

Correct! Wrong!

The electric starter is powered by the APU battery. The main airplane battery powers:

Only the inlet door.

the inlet door and the fire detection system.

The inlet door, fuel valve, overspeed detection system and fire detection system.

The inlet door, fuel valve, and fire detection system.

Correct! Wrong!

What are the operating limits for the APU Electrical Power and Bleed Air?

Electrical Power: Whole airplane operating envelope, Bleed Air: 22000ft and below.

Electrical Power: 22000ft, Bleed Air: 22000ft and below.

Electrical Power: 35000ft, Bleed Air: 22000ft and below.

Electrical Power: Whole airplane operating envelope, Bleed Air: 25000ft and below.

Correct! Wrong!

If the APU is in the attended mode, what fault causes an immediate automatic shutdown?

High oil temperature.

High EGT.

APU controller failure.

Low oil pressure.

Correct! Wrong!

In the attended mode, any of the following faults cause the APU to shut down immediately:

APU fire/inlet overtemperature, overspeed/loss of overspeed protection, and APU controller failure

APU fire/inlet overtemperature and overspeed/loss of overspeed protection

APU fire/inlet overtemperature, APU overspeed, and APU controller failure.

APU fire/inlet overtemperature, overspeed/loss of overspeed protection, APU controller failure and speed droop.

Correct! Wrong!

How long is the cool-down period for the APU attended and unattended modes automatic shutdown?

120 seconds.

60 seconds.

There is no cool-down period.

90 seconds.

Correct! Wrong!

What are the conditions for an APU automatic start?

Both backup generators fail.

RAT is deployed.

1 engine is shutdown.

Both AC transfer busses lose power.

Correct! Wrong!

If AC power is not available or no AC pump pressurizes the left fuel manifold, the DC pump in the left main tank provides APU fuel. On the ground, the APU can be started with no pumps operating.

True.

False.

Correct! Wrong!

The APU has attended and unattended operating modes. The attended mode operates when either engine is running or starting, or when the airplane is in flight. The unattended mode operates at all other times on the ground.

True.

False.

Correct! Wrong!

Boeing B777 – APU