APU Limitations

Question 1

Maximum altitude for APU start:

Answer 1

35,000 ft

Question 2

Maximum altitude for APU operation:

Answer 2

40,000 ft

Question 3

Maximum altitude for APU bleed air use:

Answer 3

20,000 ft

Question 4

Maximum altitude for APU assisted Engine Starting:

Answer 4

15,000 ft

Question 5

APU Generator on ground and in flight:

Answer 5

100%

Question 6

Maximum rotor speed:

Answer 6

108%

Question 7

Maximum Permissible EGT:

Answer 7

° During start below 50%: 974°C
° During start between 50%-90%: 974°C decreasing linearly to 718°C
° Running: 718°C
° Bleed air in use: 666°C

Question 8

Battery voltage required for APU start:

Answer 8

22 volts min.

Question 9

Do not operate ___ if ___ has been activated.

Answer 9

APU & Right Fire extinguisher

Question 10

APU is approved for ___ operations.

Answer 10

Unattended

Question 11

Allow ___ minutes cooldown periods between APU starts or between shutdown and next
APU start.

Answer 11

2

Question 12

Allow ___ minutes cool down period after ___ consecutive start attempts.

Answer 12

30 & 3

Question 13

Operate APU only if ___ standby fuel pump is operative or ___ engine is operative.

Answer 13

Right & Right

Question 14

When ground aircraft de-icing is in progress, ___ must be off with door closed.

Answer 14

APU