Fuel System

Question 1

How many tanks are in each wing and what are they?

Answer 1

The fuel system comprises two integral fuel tanks, with one tank located in each wing. Each wing tank incorporates a collector tank and a surge tank. (81214-10-10 Pg 1)

Question 2

In the right wing how many fuel pumps are there and what are they?

Answer 2

Each wing fuel tank contains the following pumps:

• Ejector fuel pump .
• Wing AC electric fuel pump .
• Three scavenge ejector pumps .
• DC electric fuel pump (right tank only) .

(812 14-10-10 Pg 5)

Question 3

What is the purpose of the AC pump?

Answer 3

The wing tanks AC electric fuel pump supplies fuel to the following components:

• Onside engine during engine starts .
• Cross side engine during crossfeed operations .
• APU, when engine is not running .

It is also a backup pump in the event of ejector pump failure. (812 14-10-10 Pg 5)

Question 4

How does the Ejector Fuel Pump work?

Answer 4

The primary wing fuel pump is a venturi ejector pump Oet pump) with no moving parts, and is powered by the respective engine motive flow. It is a self-sustained pump and does not require electrical power to operate. (812 14-10-10 Pg 5)

Question 5

Where is the fuel temperature sensed?

Answer 5

The digital information indicates the fuel temperature measured in the left fuel tank. (B12 14-10-05 Pg 3)

Question 6

When selecting the cross feed valve to LOW 1, what happens in the system?

Answer 6

Setting the crossfeed selector knob to LOW 1 position opens the crossfeed valve and activates the AC PUMP 2, feeding both engines from wing tank 2. (B12 14-10-10 Pg 6)

Question 7

What is the primary purpose of the DC fuel pump?

Answer 7

Provides pressurized fuel for normal APU operation and engine start, when AC power or the AC fuel pump is not available. (B12 14-10-10 Pg 5)

Question 8

If the total fuel quantity indication is replaced by amber dashes, what does it mean?

Answer 8

AMBER DASHED: invalid information. (B12 14-10-05 Pg 7)

Question 9

During an electrical emergency and the RAT in use, which fuel pump will be powered?

Answer 9

The right wing AC electric fuel pump (AC PUMP 2) is powered by AC ESS BUS and the DC electric fuel pump is powered by the DC ESS BUS 2. (B1214-10-10 Pg 5)

Question 10

How is the “total fuel used” reset to zero?

Answer 10

The FUEL USED indication is automatically reset by the FMS upon the first engine start. (MAU Load 21.2 and on) (B12 14-10-10 Pg 3)