In my case I was taking it straight from the FCOM PERF section and the QRH tables it tells you to use. It's not mentioned as optional anywhere, indeed overweight landing isn't mentioned in the FCOM PERF section at all for normal or failure.
The QRH tables for Conf Full and 3 Inflight Landing Dist with different braking actions have a overweight correction in addition to the weight adjustment +/- 190T. We are advised then to add 15% safety factor.
The QRH tables for inflight landing distance assessment with failure do not have the additional correction for overweight. We are advised to then add 15% safety factor but in an emergency the commander can ignore it if required.
These new graphs with all the different failures, braking actions and runway condition matrix all came out only around a year ago.
Multiple failures have been a particular pain in the rear and I believe Airbus is coming out with data for this and a methology soon? Particularly since QF 32 in SIN with all their multiple failures made it impossible for the crew to calculate!!
Last edited by nitpicker330; 24th May 2014 at 01:37.