Fuel System

Question 1

What are the four opening panels that must be inspected as a part of the pre flight security inspection?

Answer 1

Pressure refuelling port.
Battery compartment.
Forward hydraulics bay.
Air conditioning port.

Question 2

How is fuel fed to the Fuel Pump and Metering Unit (FPMU)?

Answer 2

In the main tanks, fuel flows from wingtip to the wing root collector box via gravity. The flap valves and the ejector pumps ensure the collection box remains full. One of three electric pumps ducts fuel to the FPMU.

Question 3

What is the normal operating supply of fuel to each engine?

Answer 3

The left tank supplies the left engine, the right tank supplies the right engine and the APU.

Question 4

What is the purpose of a flap valve?

Answer 4

To inhibit fuel flow to the wingtips.

Question 5

What is the fuel capacity of the ERJ-145?

Answer 5

LR
11 434 lb (1689.8 US gal) total.
5171 lb (844.9 US gal) in each tank - 39 lb (5.8 US gal) unusable.

XR
Ventral tank 1863 lb (275.3 US gal) - 21 lb (3.1 US gal) unusable.

Question 6

How does the collector box remain full?

Why is it important to keep the collector box full?

Answer 6

Gravity.
Flap valves.
Ejector pump.
To keep the fuel pumps submerged.

Question 7

How many fuel pumps are installed in each tank?

Answer 7

Three, however only one operates at a given time.

Question 8

What does the ejector pump do and how does it operate?

Answer 8

It serves to keep the collector box full.

It is a simple Venturi design driven by the positive pressure of the electric fuel pumps.

Question 9

If all electrical fuel pumps fail, are the engines able to obtain fuel? Are there any limitations?

Answer 9

The Fuel Pump and Metering Unit (FPMU) is able to draw fuel from the tanks.
Yes, only at operations below 25 000 ft.

Question 10

What powers the electrical fuel pumps?

Answer 10

Pump A - on side essential bus.
Pump B - cross side essential bus.
Pump C - on side DC bus.

Question 11

Can one pump (of the six) supply all of the fuel demands?

Answer 11

Yes, however during take-off, landing and go around it is not assured.

Question 12

Is it possible to cross feed tank to tank?

Answer 12

No, however it is possible to cross feed tank to engine.

Question 13

How does the pilot select which electric fuel pump is in operation?

Answer 13

By operation of the fuel pump selector switch on the overhead fuel panel.

Question 14

How does the pilot cross feed an engine?

Answer 14

By selection of the fuel cross feed switch on the overhead panel.
This opens the cross feed valve and turns the electric pump in the low tank off.

Question 15

What is the maximum fuel imbalance?

How does the pilot safeguard against this?

Answer 15

800 lb.

By rotating the fuel cross feed switch to the LOWER tank (i.e. selector switch tells which engine to cross feed TO).

Question 16

When do the standby fuel pumps automatically come on?

Answer 16

If the fuel pressure to the FPMUs falls to 6.5 PSI.
An EICAS message will appear and the standby pumps will cycle on and off.
The MFD will display which pump has failed.

Question 17

Where is the fuel tank temperature probe?

Answer 17

In the left tank.

Question 18

How are the fuel shutoff valves from each tank closed?

Answer 18

By action of the fire T handles.

This is the only way.

Question 19

How is the aircraft refuelled?

Answer 19

Two ways.

Through either the pressure refuelling port or the over wing fuel ports.

Question 20

Can fuelling operations occur with the engine(s) running?

Answer 20

Yes, a single engine turn and with airport permission.

Only flight crew may be on board.
Only the left engine may be operating.
No over-wing refuelling is permitted.
Aircraft must face into the wind with the main cabin door open.
A fire guard must be posted with a 20-BC rated extinguisher.
No baggage or other loading may be conducted.

Question 21

Can fuelling operations occur with passengers on board?

Answer 21

Yes.
Single Point Operations.
The fuel panel OPEN and CLOSED will determine the start and end of the fuelling operation.
Seat belt signs must remain OFF.

Over-Wing Fuelling Operations
The FA must be briefed.
Can not occur on the left side while passengers are deplaned or emplaned unless a jetbridge is in use. If passengers are on board, only stairs must be in position.
Seatbelt signs OFF.

Question 22

What powers the external pressure refuelling panel?

Answer 22

Normal - DC bus 1.

Battery - Hot bus 1.

Question 23

How is the APU fuel shutoff valve (wing root) closed?

Answer 23

APU master switch in ‘off’ position.
APU fuel shutoff button is pressed.
APU fire extinguishing button is pressed.
Automatically with an APU fire detection on the ground.

Question 24

How can fuel quantity be measured when the MFD display is inoperative?

Answer 24

By use of the direct measuring sticks.
There are three each side.
Ensure the aircraft is level (between 0 and -2° pitch and roll - consult MEL).
After refuelling, begin at the outer most stick.
Consult the fuel tables in ***.

Question 25

What is residual fuel?

Answer 25

The fuel in the collector box and the untrainable quantity.

Question 26

Can the APU be operated during fuelling operations?

Answer 26

Yes.

However it cannot be started or shutdown during the fuelling operation.