APU

Question 1

Max altitude for start

Answer 1

30000’

Question 2

Max alt for operation

Answer 2

37000’

Question 3

Max tailwind for start

Answer 3

34kts

Question 4

Max rotor speed

Answer 4

108%

Question 5

Max EGT for start

Answer 5

884C

Question 6

During APU start above 25000’ what may the EGT reach?

Answer 6

925C for 10 seconds

Question 7

Max EGT continuous

Answer 7

680C

Question 8

Min battery temp for start

Answer 8

-20C

Question 9

Min battery voltage for start

Answer 9

23.5V

Question 10

APU starter limits between 3 consecutive attempts

Answer 10

1 min OFF

Question 11

APU starter limits third cycle

Answer 11

30 min OFF

Question 12

What is the automatic start sequence? 4 points

Answer 12

The APU is energised by BATT 2
At 3% (ground) or 0% (air) it commands power to the ignition
It de-energised at 50% and becomes self sustaining
7 secs after reaching 95% it can sustain elec loads *Allow 3 minutes warm up before pneumatic loads

Question 13

How long must you wait before applying pneumatic loads on the APU after start?

Answer 13

3 minutes