Auxiliary Power Unit (APU)

Question 1

Max permissible load on the APU generator

Answer 1

40 KVA

Question 2

Max altitude for staring

Answer 2

37,000 ft

Question 3

Max altitude for APU operation

Answer 3

41,000 ft

Question 4

Max altitude for APU bleed air extraction

Answer 4

25,000 ft

Question 5

Max speed with APU door open

Answer 5

220 KIAS if APU not operating, no speed if operating

Question 6

What battery voltage is required before starting the APU?

Answer 6

22 volts on both batteries

Question 7

What does the main battery power during an APU start

Answer 7

APU ECU

Question 8

What does the APU battery power during an APU start

Answer 8

Cranking of the 28 VDC starter motor

Question 9

When will the AVAIL switch light illuminate

Answer 9

99% RPM plus 2 seconds

Question 10

APU Starts RPM and EGT

Answer 10

106% / EGT 806c

Question 11

APU takes over from engines on landing when?

Answer 11

When gear is retracted or flaps are greater than 20 degrees

Question 12

Engines take over bleeds from the APU on takeoff when?

Answer 12

When gear is up and flaps are 20 degrees or less and thrust levers out of the TOGA detent.