Systems - Fuel

Question 1

Where are fuel quantities displayed?

Answer 1

• Total fuel quantity on primary EICAS
• Tank and total quantity on the FUEL synoptic display

Question 2

Where is the fuel temperature displayed?

Answer 2

• Displayed in white on the primary EICAS, turns amber when approaching max temp or fuel freeze temp entered in the FMS

Question 3

Do all the fuel pumps have the same pressure output?

Answer 3

• No, the Center tank pumps have a higher output pressure

Question 4

With all tanks full and pumps operating, which tank supplies the engines?

Answer 4

• Center tanks first
• Main tanks

Question 5

From which tank can fuel be jettisoned?

Answer 5

• From all fuel tanks

Question 6

Where can the jettison time be observed?

Answer 6

• On the Fuel synoptic page

Question 7

On ground with only 1 electric power source, how will the tank pumps operate during engine start?

Answer 7

• The fuel system automatically determines the best pump to operate depending on the eletric power available and sheds the rest until sufficient power is available.

Question 8

What is indicated if the cross-feed switch valve light remained illuminated after selection during manual operation?

Answer 8

• The valve is not in the selected position

Question 9

Where can the fuel freeze temperature be entered?

Answer 9

• In the FMS - PERF INIT page

Question 10

What will happen when the actual temperature approaches the preset fuel freeze temperature?

Answer 10

• An EICAS advisory FUEL TEMP LOW is displayed

Question 11

Where is the DC fuel pump located?

Answer 11

• In the L main tank

Question 12

When does the DC pump operate on ground?

Answer 12

• When there is no AC power, and the APU switch is selected ON

Question 13

What will cause the DC pump to automatically shut down?

Answer 13

• When AC power is available and the L aft fuel pump operating

Question 14

If a main fuel pump fails, will selecting the pump switch off remove the message and light?

Answer 14

• No, the pressure and message FUEL PUMP (L,R FWD or AFT) is displayed anytime the switch is selected off.

Question 15

Is the engine operation affected by a tank pump off?

Answer 15

• No, the engine will continue to be supplied with fuel by either the other pump, the other tank or suction feed

Question 16

To what quantity will fuel be automatically jettisoned?

Answer 16

• To the max landing weight

Question 17

Can all the fuel be jettisoned?

Answer 17

• No, at least 3900 kgs of fuel remains in each main tank after jettisoning

Question 18

Describe the fuel balance system.

Answer 18

• Fuel balancing can be achieved by selecting the fuel balance switch fuel from the higher quantity main tank is transferred to the lower quantity main tank through the defueling and refueling valves. The transfer stops when the tanks are balanced.

Question 19

When is fuel balance operation inhibited?

Answer 19

• Refueling,
• Defueling,
• Ground transfer of fuel (using the refueling control panel),
• Engines on suction feed
• Fuel balance system failure
• Center tank pump on
• On ground with one or both engines running
• In flight with jettison system active, and
• FUEL DISAGREE / FUEL QTY LOW message

Question 20

When will the FMC show a FUEL DISAGREE message?

Answer 20

• When the Totalizer fuel and the FMC calculated fuel disagree

FUEL DISAGREE advisory is displayed when a discrepancy between the FQIS totalizer fuel quantity and the FMC-calculated fuel quantity is equal to or more than 2,268 Kg or (5000 lb) continuously for 5 minutes.

WT787-14 - Page 4 (787 WingTIPs)

Question 21

What is the nitrogen generation system?

Answer 21

It generates nitrogen enriched air to displace fuel vapors in all fuel tanks. This air minimizes fuel flammability during normal flight and ground operations.

Question 22

If there is fuel in the centre tank, and centre tanks pumps fail, is the fuel unusable?

Answer 22

• The scavange system operates automatically to t ransfer any remainin center tank fuel to the main tanks, Fuel transfer beings when either main tank quantity is less than paroximately 16,000 kilograms and the center tank pumps are off. The system is inhibited if the engine is on suction feed.