Engine, APU

Question 1

When is the APU in the UNATTENDED mode?

Answer 1

When neither engine is running or starting

Question 2

While in the unattended mode the APU will shut down for which faults?

F.O.C.S. H.E.L. G.I.N.N.

Answer 2

*Fire/inlet over temperature
*Overspeed/loss of overspeed protection
*Controller failure
*Speed droop
*High oil temperature
*EGT high
*High oil pressure
*Generator oil filter approaching bypass
*intake door failure
*No combustion on start *No acceleration on start

Question 3

When is the APU in ATTENDED mode?

Answer 3

When either engine is running or starting, or when the airplane is in flight

Question 4

Which faults cause the APU to shut down while in the ATTENDED mode (with no cool down period) and the EICAS message APU SHUTDOWN displayed?

F.O.C.S.

Answer 4

*Fire/inlet over temperature
*Overspeed/loss of overspeed protection
*Controller failure
“Speed droop

Question 5

While in the ATTENDED mode, what failure are indicated but the APU will not shut down automatically?

EICAS message: APU LIMIT

H.E.L. (I have to shut it down myself)

Answer 5

*High oil tempature
*EGT high
*Low oil pressure