A340 fuel aft transfer fault
 

hi,

had a "fuel aft transfer" failure on the climb out on a 11 hour flight.

checked the FCOMS but there was nothing mentioned. the failure came on the inop coloumn on the status page. no ecam warning.

1. if we had reset the FCMC one at a time would it have helped? and you reset the FCMC in flight?

2. how do you calculate the optimum CG for the acft. we were ony able to transfer the fuel forward manually?

3. how much would the extra fuel burn be flying an acft not at the optimum CG?

thanx. any info is much appreciated.

Absolutely yes.
It is allowed from the QRH, so why not ?You should find the value in yor company MEL. Search for the xftr sys inop and you'll see limitation(s), if any, and fuel consumption penalization.

Ciao

actually we looked in our MEL but there was nothing mentioned.
maybe some some other airline MEL might have it.

This is from our MEL for the A343 and I think the A345 is the same.

28-27-02 Aft Transfer Valve
Fuel jettison from centre tank is still operative.
The CG control is no longer available.
The fuel consumption is increased by 1.5%.

Our software has an ECAM warning for this fault. The FCOM states that the fuel burn increases by roughly 1%, so I guess the MEL covers the worst case scenario. (dispatch reasoning) It does not recommend resetting the FCMC with this ECAM. It is a long procedure but essentially it says to manually XFR the fuel forward. It then goes on to state that if the man xfr doesn't work, then do the same procedure but only above 270kts and not in climb. (gravity does the work then)

thank you very much.
our 340's are much older.hence i guess no ecam warning.
but how would you know when to transfer the fuel? ( except at 5000kg when it anyway transfers )
i.e. the CG varies with the weight. is there any way of finding the optimum CG?

On FCOM 1.28.10 on chapter "CG Control - Trim tank transfer" there is a graph showing the CG target according different weights.
We don't have ECAM warning, so we consider the FCMC reset according the QRH part Abnormal Procedure, "reset of computer".
QRH says it is allowed and there are two cases, before and after eng start. Of course before I have to refer to MEL, after I'll proceed to the reset.
;)