FUEL Panel (Rev. 5)

Question 1

Generally, what is the total fuel capacity?

Answer 1

42,000 lbs

Question 2

Why is it possible for there to be a value higher than 42,000 lbs indicated on the ECAM FOB?

Answer 2

The fuel can expand by 2% without venting overboard

Question 3

How many fuel pumps are on the aircraft and where are they located?

Answer 3

• There are seven total fuel pumps: two center tank pumps, four wing tank pumps, (two in each wing) and one APU fuel pump. On some aircraft, the center tank pumps are jet pumps, which transfer fuel from the center tank into the wing tanks.
• The APU pump is used when fuel feed pressure is low (due to loss of tank pumps or loss of normal AC electrical supply)

Question 4

Explain the flow of fuel from before engine start to climb (assume full tanks)

Answer 4

• At engine start the fuel is fed from the wing tanks
• After an engine is started, the center tank pumps turn on and continue to run for 2 minutes.
• If slats are selected within those 2 minutes, the center tank pumps will continue to run until the time has elapsed, then they will stop.
• If the slats are extended at any other time, the center pumps will shut off.
• At takeoff, the engines feed fuel from their respective wing tanks.
• When slats are retracted to zero, the fuel is fed from the center tank.
• When the center tank runs low, the pumps continue to run for 5 min.

Question 5

What is the difference between CTR TK Pump on a A319 and some older
A320’s (601 - 628) versus CTR TK XFR (transfer) on the A321 and newer
A320’s (629 – 656, 690 - 696, 901 - 915)?

Answer 5

• CTR TK Pumps are identical to the main tank fuel pumps

- CTR TK XFR are jet pumps that transfer center tank fuel to the main L (R) pumps

Question 6

What does a fault light in one of the L(R) TK PUMPS pushbuttons indicate?

Answer 6

Low delivery pressure

Question 7

What does a fault light in the MODE selector on the fuel panel indicate?

Answer 7

• Failure of the AUTO mode

- Center tank has more than 550 lbs and either wing tank has less than 11,000 lbs

Question 8

How would a pilot know that fueling is in progress?

Answer 8

• REFUELG message appears on the ECAM.

- This does not mean the fuel is entering the tanks, merely that the refueling door is open

Question 9

Describe IDG cooling and how it relates to the FADEC

Answer 9

• Some of the fuel supplied to each engine goes from the high-pressure fuel line in that engine, through the integrated drive generator (IDG) heat exchanger (where it absorbs heat), to the fuel return valve, and back to
  either the wing tank or outer tank, depending on the aircraft.
• This operation ensures IDG cooling when the oil temperature is high or when at low engine power
• The FADEC controls the fuel return depending on the temperature of the IDG – the higher the temperature, the higher the flow

Question 10

What happens if returned IDG cooling fuel fills the wing tanks while the center tanks are feeding?

Answer 10

The center tank pumps will cut off until the wing tank quantity is reduced by 1,100 lbs in the inner tanks.

Question 11

What is the approximate fuel capacity of each outer fuel tank, when installed?

Answer 11

Approx. 1,500 lbs

Question 12

When do the wing outer tanks drain into the inner tanks?

Answer 12

• When the inner tank quantity reaches approximately 1,650 lbs

Question 13

If only one inner tank reaches 1,650 lbs, what happens to the other transfer valve?

Answer 13

• All four transfer valves open

Question 14

Once opened to transfer fuel, how are the fuel transfer valves closed?

Answer 14

• Automatically at the next refueling operation as long as there is AC power on the aircraft.

Question 15

Describe the layout of the fuel tanks.

Answer 15

• The fuel tank layout depends on the specific aircraft.
• Fuel is stored in a center tank and wing tanks:
  
  • On A319s and A320s, the wing tanks are divided into inner tanks, outer tanks, and vent tanks
  • On A321s, the wing tanks are not divided into inner and outer tanks, but still have vent tanks.