Fuel System

Question 1

How many pumps are there per tank and are they AC or DC?

Answer 1

x2 AC powered pumps. A single pump can supply sufficient fuel to operate one engine under all conditions.

Question 2

What is ‘different’ in terms of pumps in the Left tank?

Answer 2

It also contains a DC powered pump. There are no controls or indicators (other than fuel synoptic). It operates automatically to provide APU when AC power is not avail and the APU selector is ON.

Question 3

If fuel pump pressure is low can the engines suction feed?

Answer 3

Yes.

Question 4

Max fuel load -200/-300?

Answer 4

Approx 137.5T (29.1/79.3/29.1) so full wings 58T and 145.5T (31.3/82.9/31.3) so full wings 62T.

Question 5

How much fuel would remain in tanks following a complete jettison?

Answer 5

• 200 = 5.2T in EACH tank (10.4T)

- 300 = 3.8T in EACH tank (7.6T)

Question 6

What is the approximate jettison rate?

Answer 6

2500kg/min all tanks or 1400kg/min main tanks only.

Question 7

Approximately when might you receive a “Fuel Imbalance” EICAS? Is there a maximum fuel imbalance?

Answer 7

Depends on main tank fuel quantity but approx when the imbalance is around 1500kg. Max fuel imbalance - see Load and Balance 1.9.7. Depending on fuel load any imbalance above 1360kg will need to be ‘resolved’.

Question 8

Approximately when might you trigger the EICAS ‘FUEL QTY LOW”

Answer 8

Either main tank 2000kgs.