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RJET E170 Study Guide 12B > APU > Flashcards

Flashcards in APU Deck (44):
1

What kind of APU is on the aircraft?

Sundstrand APS 2300

2

Describe the APU

- Constant speed
- Single-stage smeller with a 2-stage axial-flow turbine

3

What is the voltage and kVA of the APU?

115VAC, 40 kVA

4

What monitors and controls the APU?

Its own dedicated FADEC

5

What battery is used for the APU start?

- BATT 2 powers the starter
- BATT 1 powers the FADEC and EICAS for monitoring

6

What is the fuel source for the APU when the engines are running?

Right fuel tank (ejector pump)

7

What fuel pump is used for APU start?

- When BATTs on only: DC fuel pump
- AC power on: AC fuel pump
- DC power only: DC fuel pump

8

What normally provides fuel to the APU when the engine is not running?

- #2 fuel tank
- AC power: AC fuel pump
- DC power only: DC fuel pump

9

When does APU electrical and pneumatic loading become available?

3 seconds after the APU speed has reached 95%

10

Describe the APU start sequence during a ground start

Starter engagement, ignition at 6%, fuel after 0.5 secs and starter cutout at 50%

11

Describe the APU start sequence during an in-flight start

Starter engagement, ignition at 7-17%, fuel after 0.5 secs and starter cutout at 50%

12

Will the APU shutdown automatically if speed and acceleration rate isn't reached in starting cycle time?

Yes

13

What indication would you have of an APU auto-shutdown?

An APU FAIL EICAS message

14

What does moving the APU start switch to OFF do?

- Initiates normal shutdown
- 1 min cool down
- Pneumatics removed immediately and electrical power is removed after the 1 minute cool down

15

What happens when you rotate the APU master switch to ON?

Powers the FADEC and opens the APU shutoff valve

16

Can the APU shutdown be cancelled?

Yes, by moving the START switch back to ON before the 1 min cool down is over

17

Can the APU pneumatics be used during the cool down period?

No

18

Can the APU electrical power be used during the cool down period?

Yes

19

How is the APU shutdown immediately?

- APU EMER STOP button
- No 1 min cool down

20

What is indicated by an illuminated red bar in the upper half of the EMER STOP button?

An APU fire

21

What BUS provides APU fire protection>

DC ESS BUS 2

22

What BUS provides APU fire detection?

DC ESS 1 and 2 (Using MAU 1 and 2). I think it may just be DC ESS BUS 1

23

What happens when the APU EMERGENCY STOP button is pushed?

The APU fuel shutoff valve closes and the APU still shut down with no cooling period. A white stripe displays on the switch

24

Selecting the APU control MASTER selector knob from On to OFF initiates a normal APU shutdown, monitored and controlled by?

FADEC

25

How is the APU monitored and controlled?

FADEC

26

What will happen if batteries are turned OFF during the 1-minute cool down period?

APU will shut down immediately

27

When will automatic shutdown of the APU occur?

-Ground: overspeed, underspeed, FADEC critical fault, fire, EGT overtime, sensor failure, high oil temp, low oil pressure
- Flight: Overspeed, underspeed, FADEC critical fault

28

The APU can be used for pneumatics to a max of what altitude?

15,000 feet

29

What is the max altitude for operation of the APU electrical?

33,000 feet

30

What is the max altitude for APU start?

30,000 feet

31

Up to what altitude may the APU assist in engine start?

21,000 feet

32

On which display would the crew find info regarding the operational status of the APU?

EICAS

33

Where would you find the APU RPM and EGT indications?

On EICAS

34

If both engine bleed and APU bleed is available which one has priority?

Engine bleed

35

During APU start where does the fuel come from and what pump does it use when only DC power is available?

Right fuel pump and DC pump until AC power is available, then AC pump takes over

36

With the right engine running and the APU running where does the fuel come from?

Engine ejector pump?

37

The AMS controls the APU and engine bleeds. During an engine start what happens to the bleed valves?

The APU bleed valve opens which supplies the bleed air for the start. After the start the engine bleed valve opens and the APU bleed valve closes

38

Do you get the APU cool down period when you press the APU emergency stop button?

No

39

If you need the APU 50 secs into shutdown is there a way to get it back?

Yes, turn the APU master switch back to ON

40

How would you operate the APU while using from from Tank 1?

Select XFEED selector to LOW 2

41

In normal operations on the ground with APU running it would be normal to see the fuel imbalanced with less fuel in which tank?

Right tank

42

Can the APU be started after a critical fault?

No

43

Will the APU auto-shutdown inflight for an APU fire?

No

44

What is the APU starter duty cycle?

-1st and 2nd attempt: 60 secs on/60 seconds off
3rd: 60 secs ON/5 mins off