Fuel System Flashcards Preview

CRJ900 Limitations, Systems > Fuel System > Flashcards

Flashcards in Fuel System Deck (25):
1

What path does a molecule take from the center tank to the engines?

1. Center tank
2. Transfer ejector
3. Wings
4. Gravity(primary), scavenger ejector(secondary)
5. Collector tank
6. Main ejector or boost pump
7. SOV
8. Filter
9. Engines

2

Scavenger ejectors

2 in each wing and they transfer off the lowest part of the wing to the collector tank

3

How do ejectors move fuel

Motive flow

4

What creates motive flow

Eng. driven fuel pump

5

Transfer ejectors

Moves fuel from center tanks to the wings

6

What send fuel to the collector tanks

Flapper check valves through gravity and through the scavenger ejectors

7

Main ejectors

Sends fuel from the collector tanks to the eng. driven fuel pumps

8

What must happen before the fuel system computer can transfer from center tank to the wing tank?

One engine must be running and fuel in the main tanks below 94%

9

When will boost pumps turn on automatically?

If the main ejectors fail

10

What creates positive pressure in the wing fuel tanks?

NACA scoops and vent lines

11

Why are pressure refueling limits higher than gravity limits?

Fuel cap is lower than highest point in tank

12

What happens when fuel pressure is low with both pumps armed?

Both pumps will come on

13

What tank can't be fueled using gravity?

Center tank

14

How would you manually cross flow if auto cross flow failed

Low side XFLOW switch

15

Why do you have to be especially careful during manual cross flow?

There are no protections until your imbalance is above 800 lbs

16

What indication would you receive if the Refuel/De-Fuel computer was left on?

"Auto XFLOW inhibit" status

17

How is the fuel kept above 5* C?

Oil/Fuel heat exchanger

18

What is the MLI?

Magnetic level indicator - to manually check fuel loads

19

Why might you see an increase in the center fuel tank after takeoff?

Fuel back flows through the vent lines

20

Where is the bulk temperature fuel probe and readout located?

EICAS right main tank

21

How do you reset FUEL USED value on the FUEL synoptic page

Fuel used reset through the EICAS menu page

22

What would it mean if the powered cross flow pump depiction on the EICAS synoptic page was Amber?
PSM 13-30-3

The pump failed

23

What are the functions of the fuel boost pumps?
PSM 13-40-1

1. Supplies fuel to the engines during start
2. Backup to the main ejectors if they fail

24

What bus is the AZpU fuel pump on?
PSM 13-40-7

Battery bus

25

What prevents overfilling of the fuel tanks?

High level sensors