APU Flashcards Preview

CL-65 (900) Study Guide > APU > Flashcards

Flashcards in APU Deck (22):
1

Max permissible load on the APU generator?

40 KVA

2

Max Altitude for starting?

37,000 ft

3

Max Altitude for APU operation?

41,000 ft

4

Max Altitude for APU bleed air extraction?

25,000 ft

5

Max speed with APU door open?

220 kias if APU not running, otherwise no restriction

6

What batter voltage is required before starting the APU?

22 volts on both batteries

7

What does the main battery power during an APU start?

APU ECU

8

What does the APU battery power during an APU start?

The 28v DC electric start motor

9

When will the AVAIL switchlight illuminate?

99% rpm + 2 seconds

10

What is the purpose of the internal bypass valve?

Allows APU to continue to run if APU pump fails

11

APU Bleed Air is controlled by modulating

APU LCV(Load Control Valve

12

APU bleed pressure readout can be monitored on?

EICAS "ECS" synoptic page

13

The APU gauges(RPM and EGT) appear on EICAS when:

APU POWER / FUEL switch light is pressed in

14

"APU OVERSPEED" warning message is displayed when RPM exceeds:

106%

15

When does APU ignition turn off during a start?

95% rpm

16

When does the APU starter motor disengage?

46% rpm when on ground

60% RPM when in flight

17

The battery master is ON and the PWR FUEL switchlight is pressed, what then occurs?

  • The ECU is powered
  • APU IN BITE
  • APU Fuel pump activates
  • APU RPM and EGT gauges appear
  • Fuel SOV opens
  • APU air inlet door opens

18

Can the APU be used for Anti Ice Bleed Air?

No

19

Can the APU bleed air and another source of bleed air be used at the same time?

no

20

What valve opens when the APU is providing electrical power above 17,000 ft?

The Surge Control Valve (SCV).  The opening of this valve helps to reduce the chance of APU surges when operating in an unloaded bleed air condition

21

How many squibs does the APU fire bottle have?

1

22

When will the APU ECU inhibit a start due to APU RPM?

The APU ECU will inhibit a start while on the ground if the RPM exceeds 5% or in flight if the RPM exceeds 12%