Fuel System

Question 1

How many fuel tanks does the a/c have?

Answer 1

1x C tank
2x Main tanks (L & R)
2x surge tanks

Question 2

What connects the L & R fuel manifolds?

Answer 2

A fuel cross feed system (through 2 cross feed valves)

Question 3

The L & R main fuel tanks contain ?

Answer 3

2x AC motor driven fuel pumps

Question 4

The C fuel tank contains how many pumps? What is significant about their output pressure? What are they used for?

Answer 4

2x AC motor driven override/jettison pumps

Higher output pressure than the main tank pumps

Used for normal fuel feed as well as jettisoning

Question 5

What feeds fuel to the APU until AC power is established?

Answer 5

A DC fuel pump, located in the L main tank

Question 6

What assists the C tank pumps in jettisoning fuel from all 3 tanks?

Answer 6

Jettison pumps located in each main tank (1 in each main tank)

Question 7

How do you know how much fuel you have in the tanks?

Answer 7

Each fuel tank contains sensors that input their data to the FQIS (Fuel Quantity Indicating System)

Question 8

Fuel quantity is calculated based on ?

Answer 8

Fuel height (in the tank) & the density

Question 9

When AC power is established & the APU is running, the L FWD fuel pump…..

Answer 9

Automatically operates regardless of switch position.

The pump pressure light is extinguished indicating L FWD fuel pump operation.

Question 10

When an AC power has not been established & the APU is running, what supplies fuel to the APU?

Answer 10

A DC fuel pump

Question 11

The C tank pumps have a higher output pressure than the main tank pumps, as a result…..

Answer 11

The L C pump overrides the L main tank pumps to feed fuel to the APU

Question 12

When the engines are started which valves open?

Answer 12

The spar & engine fuel valves open (feeding C tank fuel to the engines)

Question 13

Initially, fuel is burnt from the C tank because ?

Answer 13

Because of the higher output of its override pumps

Question 14

Whats the function of the scavenge pumps?

Answer 14

Automatic transfer of any residual C tank fuel into the main tanks

Question 15

Fuel jettisoning defaults to leave the a/c at ?

Answer 15

Max Landing Weight

Question 16

When the a/c is heavy and loaded near the forward CoG, fuel is jettisoned from the ?

Answer 16

C tank first (to keep within CoG limits).
Main tank jettison is delayed.

Question 17

CBT data - Standpipes ensure at least how much fuel remains in each main tank after fuel jettison is complete?

Answer 17

5,200 kgs FCOM says 3,800 kg in each main tank 12.20.6

Question 18

Can all C tank be jettisoned?

Answer 18

Yes

Question 19

With no AC power available, what supplies fuel to operate the APU?

Answer 19

The APU is fed by a DC pump in the L main tank