A320 outer tanks

[ulisse]

Hello airbus pilots.
I'm wondering to know if with the outer tank empty due to refueling without ac power the airplane is release to fly

It happens some time tath I found it empty and I believe Mr airbus daes it not even think to this possibility, in fact I had some report tath in this condition the warning "outer tank temp high" may come on (in very hot days)

Any info on tath?

Regards

[EGPFlyer]

Yes it's allowed. The minimum fuel for take off is just 1500KG which would mean the outer tanks must be empty.

[pilot-737]

If you want to be sure about the actual aircraft... Just check the Mel -> xfer valves fault (or failed) in open position .... If the dispatch is granted you have the official answer :) (which is YES you can ;) )
Outer tank high temp may be triggered On a very hot day... But if you look "through" the procedure(fuel l (r) outer tank high temp) the real problem exists while the outer tank is full and your temp is high ... The procedure is to disconnect the idg or to increase your fuel flow to try to cool down your idg and this applies at temps 65 or 57 degrees while the auto ignition temp Is around 210 degrees .... So the real concern is rather your idg overheat I think :) your ecam advisory MSG is triggered for fuel temp higher than 45 or 55 degrees and the recommended action is to switch your galley power off (reduce your idg loads )

[Meikleour]

ulisse: When you have a/c power on the aircraft why don't you just do a "ground transfer of fuel" to refill the outers? The old FCOM2 refers. Only takes about 5 minutes - same as the walkaround! I have frequently done this.

PS: remember to have the crossfeed open otherwise you will cock up the distribution! NB

[Roger Greendeck]

Without power the valves wont close when you refuel. There is a CofG correction in the FCOM so that you don't need to transfer the fuel once you have power on to be within limits.

[ulisse]

Thanks to every one wich give some highlights on this matter

My idea on tath is related on the principle tath if it has been designed in a way can not work in a different way or at leas you are exploring on your own a field where you can find some surprise (I.e. triggering unusual ecam warning)

But such as principle daes not work on airbus machines

[Natstrackalpha]

Yes it's allowed. The minimum fuel for take off is just 1500KG which would mean the outer tanks must be empty.

possibly true, however, there will still be fuel fed to the outers from the IDGs.
So you might takeoff with tips empty but they would not remain empty but of course would flow to the other tanks, eventually, there is no transfer per se in the air, as you know.

[WhyByFlier]

It's happened because you have refuelled on BATT only.

As soon as the engines are started the outer tanks fill up because of the IDG/Fuel heat exchanger which returns fuel to the outer tanks.

The transfer valves run off DC not AC.

[737Jock]

FCOM PER-LOD-FUL FUEL

GROUND FUEL TRANSFER
Applicable to: ALL
On cockpit overhead FUEL panel
PUMPS (of the tanks not to be defueled) OFF
MODE SEL MAN
PUMPS (of the tank to be defueled) ON
if left wing and/or center tanks is (are) to be defueled :
X FEED ON
OPEN light comes on.
On refueling control panel :
REFUEL VALVES (of tanks not to be filled) SHUT
REFUEL VALVES (of tanks to be filled) OPEN
MODE SELECT DEFUEL/XFR
OPEN light comes on.
FUEL QTY MONITOR
When the tank contents reach the required level :
Corresponding REFUEL VALVES SHUT
MODE SELECT OFF*and*GUARDED
OPEN light goes out.
REFUEL VALVES NORM*and*GUARDED
Set cockpit FUEL panel to normal configuration.

However operators operating with the LPC can simply enter the fuel loads per tank in the weight and balance module fuel tab.
There is no restriction on flying with the tip tanks empty, but obviously there is a weight and balance concern.

Also when the engines run the tip tanks will slowly fill, as the fuel that is used to cool the idg oil is recirculated into the tip tanks.