Eurotraveller,
Going into AIDS, as
Bus Driver Man suggests, can be a bit inconvenient. There was a thread about Green Dot in October, which may be of interest:
http://www.pprune.org/tech-log/46643...ml#post6757000
For the A320, Green Dot = ([GW in tonnes] X 2) + 85 + (1kt/1000ft in excess of FL200)
So a discrepancy of 15kt would equate to 7.5 tonnes. That would be excessive, and suggest a gross error in the loadsheet. I never saw more than 10kt (5 tonnes). There is sometimes a discrepancy between the two FACs, but I never saw more than about 3kt. This suggests that the FACs (and AoA probes) are fairly consistent.