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openings when inner wing tank fuel level reaches 1,650 lbs. When either wing
inner tank reaches the 1,650 lbs. level a signal is sent to latch open all the
transfer valves in both outer wing tanks. This is a total of 4 valves, 2 in each
outer wing tank. The transfer valves will remain open for the rest of the flight and
will close on the next refuel operation. If fuel is “sloshed” during climb or descent
it is possible for the transfer valves to be opened early due to a LO LEVEL alert.
An ECAM caution is given if during Auto mode the center tank has more than
550 lbs. of fuel while the left or right wing tank has less than 11,000 lbs. of fuel
per wing. This would indicate that the normal Auto schedule was not being
followed.
The Crossfeed pb is normally extinguished when the valve is closed. It will show
white ON when selected on and green OPEN when fully open. The Crossfeed
valve itself is powered by two electric motors. Opening the Crossfeed valve
enables one engine to be fed by both sides and/or the center or both engines to
be fed by one side and/or the center.
There are two full levels for the inner wing tanks, a fueling full and an operational
full. The fueling full is less than the operational full and that allows the extra IDG
fuel room to collect in normal circumstances without triggering the center tank
pump turn-off for IDG return fuel.
US Airways Airbus A319, A320, A321 Notes
16
Note: In Auto the center tank pumps run all the time if center tank fuel is present
so with all fuel pumps on if you are on the gate with APU running (slats up) you
will be using center tank fuel. If operating in Manual mode the crew must ensure
that the center tank pumps are off when the wing tanks are completely full or
when the center tank is empty.
Note: Unusable fuel is shown with a half amber box around the fuel quantity on
ECAM. If the fuel quantity is in a degraded mode the ECAM fuel quantity will
have amber dashes through the last two digits. Refuel is shown on upper ECAM
memo when refueling door is open.
A321 differences:
The A321 Center Tank does not have the same electric pumps as the A319/320
but uses jet pumps instead. Further, the jet pumps are “powered” by fuel
pressure from the fuel pumps in the main wing tanks and the jet pumps transfer
fuel from the Center tank to the respective wing tank. The A321 wing tanks do
not have an outer and inner tank and there are no transfer valves to latch open.
All the wing fuel is in one wing tank and total wing fuel remains the same as the
A319/320. Please understand that the pumps in the wing must be running in
order to power the center tank jet pumps and transfer fuel.
The center tanks pump pb’s have been replaced on the A321 with transfer valve
pb’s. Essentially these CTR TK L (R) XFR pb’s handle the same function as the
center tank pb’s on the A319 and A320. In Auto mode they will control the valves
that allow the jet pumps to operate once the wing fuel has been burned down
550 lbs. Once the wing fuel tank is again full the transfer will stop until the tank is
burned down 550 lbs. again. This will continue until all center fuel has been used.
If the FUEL MODE SEL pb is in MAN then the center tank transfer valves will
open and must be turned off to avoid overfilling the wing tanks. If in MAN they
should also be turned OFF once all center tank fuel is gone.
Note: IDG return fuel is added to the wing tank as there is no outer tank on the
A321.
Note: There is no ECAM OUTR TK FUEL XFRD memo on the A321 as there is
no outer or inner wing tank (all fuel in one wing tank). However, there is a memo
“FOB below 3T” and while rather cryptic I have been able to translate this as
Fuel On Board below three Tons (possibly Tonnes?). So you still have a sort of
low fuel message at around 6,000 lbs.
The A321 has two Additional Center Tanks that will automatically feed to the
Center tank when the Center tank burns down to a certain level defined as when
the high tank level sensor is dry for 10 mins. The Additional Center Tanks do not
have pumps but use cabin air pressure to feed the center tank through transfer
valves. The ACT 2 (aft tank) will transfer fuel first followed by the ACT1. All fuel
US Airways Airbus A319, A320, A321 Notes
17
transfer is done automatically in the normal mode of operation. The automatic
fuel transfer from ACT to Center Tank is noted on the ECAM as a green triangle
between the ACT fuel indicators.
An additional pb has been added to the FUEL panel to control the ACT fuel
transfer. Yes, you guessed it, the normal mode is AUTO (are we seeing a pattern
here?). In AUTO mode the ACT pb allows automatic control of the fuel transfer
　
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