Takeoff Performance Question

[HERC]

Hi,

I have a question regarding calculating takeoff performance where the TOGW is calculated to be more than its design MTOW.

If the calculated Max TOW is greater than the Design Structural Takeoff Weight, to which weight should one apply performance penalties (if applicable)?

Like Design Structural Weight is say 220 tonnes for A3xx but for the day at temperature & QNH its over 256 tonnes. Now if a performance penalty is to be applied owing to MEL item(s), should it be applied to 220 tonnes or 256 tonnes?

Thanks!

[felixthecat]

Apply to the calculated RTOW, unless the MEL says it should be applied somewhere else i.e. climb limit weight or the like. Obviously the TOW cannot be greater than the lowest of either the Calculated RTOW minus the performance reduction or the Max structural.

[mutt]

The reason that they publish values higher than the Structural Weight is so that you can apply penalties to this weight without actually affecting your takeoff weight.

[HERC]

Thanks felixthecat and mutt for your replies.