Regarding the fuel figures. We always enter the exact value displayed on ECAM (well, maximum +/- 50 kg) and still get the message...
So more or less back to square one.
Alas I don't have any specifics on this system right now.
Then your quest awaits, Sir!
Joking aside and rather off-topic, this reminds me a lot of the 'CG DISAG (FUEL)' message that one could get on the MD11. Similarly to the Airbuses, the setup here was that the loadsheet ZFW/ZFWCG values are entered in the WEIGHT INIT page (the MD11 equivalent of INIT B. Infact, the MD11 CDU interface is a lot like the Airbus MCDU one, albeit rather more basic, e.g. no colours) and are then used by the FSC (Fuel System Controller) to calculate and display the GW/GWCG on the SD.
The important difference, of course, is that in addition to the ZFW/ZFWCG, the loadsheet TOW/TOCG are also entered in the FMS. Now, if one entered wrong TOW/TOCG values, which were sufficiently different to the FSC-derived GW/GWCG (there is some tolerance; to account for taxi fuel, for one), after start-up, one would get the aforementioned 'CG DISAG (FUEL)' message, defined as:
CG DISAG (FUEL) - Disagreement between the aircraft CG displayed on the SD and the CG entered in the FMS. Confirm fuel load and entered data.
This would happen more often if doing a manual loadsheet (ours were drop-line type), as the 'CG change due to fuel' measurement on a manual loadsheet is, ofcourse, less precise than that of a computer loadsheet or the FSC calculation.
So in summary of the above, on the MD11, there is a clear opportunity for a weight/CG discrepancy. Where is discrepancy arising on the A330?
Perhaps it's just a case of a momentary lapse of communication between the FMGECs/FCMCs? Or a case of a GWCG based on an assumed/standard fuel distribution in the FMGECs vs actual/non-standard fuel distribution in the FCMCs?
Uplinker, I got your post in a notification email, but it seems that you've deleted it from the forum?