APU

Question 1

How long do you need to wait after selecting the APU Master SW ON, before selecting START?

Answer 1

At least 3 seconds

Question 2

Required cooling time between each start attempt

Answer 2

1 minute

Question 3

Required cooling time after three consecutive start attempts

Answer 3

60 minutes

Question 4

The APU automatically shuts down at what percent N speed?

Answer 4

107%

Question 5

APU Start/Shutdown during Refueling/Defueling limitations

Answer 5

During refueling, APU start/shutdown is permitted with the following restrictions:

• If the APU failed to start, do not restart
• If the APU did an auto shutdown, do not restart
• If a fuel spill occurs, perform a shutdown

Question 6

Max altitude for APU start using battery power only (Elec Emergency Configuration)

Answer 6

25,000 feet MSL

Question 7

Max altitude for APU start using normal electrics

Answer 7

39,000 ft MSL

Question 8

Max altitude for APU use using one pack and electrical

Answer 8

22,500 ft MSL

Question 9

Max altitude for APU use using two packs and electrical

Answer 9

15,000 ft MSL

Question 10

Max altitude for Engine start using APU

Answer 10

20,000 ft MSL

Question 11

Can the APU bleed be turned on when the wing anti-ice is on?

Answer 11

No, it is prohibited