APU

Question 1

APU START limitations

Answer 1

after 3 consecutive starts, must wait 60 min before new start

Question 2

APU MAX N SPEED (ROTOR SPEED)

Answer 2

107%

Question 3

MAX EGT FOR APU START 
1.  BELOW 25000”
2  ABOVE 25000”
3. 5s after APU shutdown 
4. For immediate shut down

Answer 3

1. BELOW 25000” = 900 degrees C
   2 ABOVE 25000” = 982
2. 5s after APU shutdown = 682
3. For immediate shut down = 700 - 742

Question 4

APU ENVIRONMENTAL ENVELOPE

BLEED AIR + ELEC / ELEC ONLY

Answer 4

BLEED AIR AND ELEC POWER:
ELEVATION = -2000 to 25000” (battery starter limit)

ELEC POWER ONLY:
25000-41000”

• EMER ELEC CONFIG UNTIL 25000” then can use APU

Question 5

APU BLEED MAX ALT

1. To assist ENG START
2. For ac and press (1 pack)
3. For ac and press (2 packs)

Answer 5

1. To assist ENG START = 20000”
2. For ac and press (1 pack) = 20000”
3. For ac and press (2 packs) = 15000”