OW landing distance with failure. Airbus clarification below:
The reason is that with the first performance databases used to calculate the In Flight Landing Distances (IFLD) with failure, the conservatism linked to the in-flight failure was enough. Therefore, at that time, there was no need to apply any additional margin. But now, with the latest performance databases, the modeling of the in-flight failure impact has been reviewed, and for some failures, the conservatism linked to the failure may be lower than the conservatism linked to the Overweight Landing Procedure. In that case, an Overweight Landing Procedure correction should be added.
Please note that a study is already on-going to add the Overweight Landing Procedure corrections in the QRH for the IFLD tables with failure. The new tables and method are presented during Regional Seminars this year.
In the meantime, in the case of Overweight Landing Procedure, the flight crew can use the Overweight Landing Procedure correction published in the QRH (For the In-Flight Landing Distances without failure) to calculate the Landing Distance with an in-flight failure.