B757 Fuel System

Question 1

FUEL CONFIG and/or

LOW FUEL light

Answer 1

Left or right main tank > 2200 lbs

Question 2

Fuel Temp

Answer 2

Sensor in the right main tank

Question 3

How many pumps per tank?

Answer 3

Two AC powered pumps

One pump is sufficient to operate one engine

Question 4

What’s the pump priority?

Answer 4

Center tanks are more powerful than main tanks

Question 5

Low pump output what happens?

Answer 5

Affiliated Switch PRESS light

EICAS message

Question 6

What happens below 50% N3?

Answer 6

The Center tank pumps are inhibited to reduce electrical loads.

Both CTR tank pumps inhibited when engines shut down

Question 7

How is APU FUEL feed controlled?

Answer 7

• APU is supplied by the left fuel manifold.
• When the APU - on, It is automatically provided via a DC powered Fuel Pump to ensure fuel is supplied when AC Power is unavailable.
• AC PWR AVAILABLE - left forward AC FUEL PUMP operated automatically, regardless of pump switch position

Question 8

Total Fuel Capacity

Answer 8

75,549 lbs

11,276 gallons

Question 9

Center Tank Fuel Capacity

Answer 9

46,391 lbs

6,924 gallons

Question 10

L and R Main Tank Capacities

Answer 10

14,579 lbs

Question 11

Minimum Fuel Temperature

Answer 11

-45 C

Question 12

Emergency Fuel

Answer 12

5,000 lbs

Question 13

FUEL CONFIG light

Answer 13

1. L and R main tanks differ by 1800 lbs
2. CTR Fuel pump switches are OFF w/>1200 lbs in the CTR tank
3. Low fuel qty - LOW FUEL EICAS displays

Question 14

FMS CDU FUEL messages?

Answer 14

INSUFFICIENT FUEL
- predicted FUEL at the destination is less than FMC reserves

FUEL DISAGREE-PROG 2
Fuel totalizer and calculated fuel quantity disagree

Question 15

How many FUEL EICAS msgs are there?

Answer 15

13

Question 16

How is unusable fuel in the center tank handled?

Answer 16

CTR tank fuel scavenge system operates - transfers fuel to the left main tank.

Begins when left main tank is approx half empty.

Question 17

CTR Tank Pumps power removal?

Answer 17

Seconds after CTR L or R FUEL PUMP msg on EICAS, power automatically removed from respective pump.

Respect pump to on resets the pump

Question 18

When is L or R SYS PRESS msg inhibited?

Answer 18

When either fuel cross feed valves are open

Question 19

What is another automatic providing fuel measure?

Answer 19

Suction feed
• Low fuel pump pressure
• line that bypasses pump feeds direct to corresponding Engine.