ATA 49 - APU

Question 1

During refuel/defuel operations, when must not be used APU ?

Answer 1

• 1st attempt to start APU has failed
• Auto shutdown has occurred
• Fuel spillage

Question 2

Which tank supplies APU ?

Answer 2

Left inner tank.
If no pressure, APU pump activates

Question 3

Function of APU Master SW ?

Answer 3

• ECB self test
• Opens flap
• Opens fuel line

Question 4

On which electrical bus APU starts ?

Answer 4

DC BAT bus

Question 5

LOW OIL QTY on APU. Can you operate APU ?

Answer 5

Yes, 10h max

Question 6

Low oil pressure on APU. Can you operate it ?

Answer 6

No

Question 7

Parameters when APU is AVAIL ?

Answer 7

N > 99 %
or
N =95% + 2s

Question 8

If APU bleed used, what time APU keeps running automatically after APU MASTER SW OFF?

Answer 8

1or 2 min for cooling purpose

Question 9

How many start attemps for APU ? Cooling period ?

Answer 9

3 attempts. 60 min cooling

Question 10

Can APU bleed be used for wings anti ice ?

Answer 10

No. Not powerful enough

Question 11

List bleed priority, APU vs Engines ?

Answer 11

1/ APU
2/ENGINES

Question 12

Can you start the APU using the aircraft BATTERIES ?

Answer 12

Yes

Question 13

APU N limit on ECAM for amber ? Red ?

Answer 13

Amber = 102 %
Red = 107 %

Question 14

What is the name of the computer that controls APU ?

Answer 14

Electronic Control Box (ECB)

Question 15

If APU is started on batteries only, how much time maximum between batteries selected on AUTO and APU start ?

Answer 15

30 min
After 35 min batteries are 25% of their capacities

Question 16

If you have an automatic shutdown of the APU or you fail to start the APU on 1st attempt, wht do you check before starting again APU ?

Answer 16

Refuelling operations. It is forbiden to start again APU while refueling