Hi all, this question is from a legal perspective, so please avoid "but that's airmanship comments". If you do your take-off performance with say 10 kts headwind on the EFB, are we allowed to depart if the wind drops to 6 kts head when we reach the holding point. I know it's taking into account just 50 pct of the headwind but can we "eat" that margin before we even press TOGA, or is a new calc required ? Same regarding temperature. We did the performance with for example 22 deg C. At the time we get to the holding point temperature is now 23 deg C. Are we legally allowed to depart without a new calculation. And QNH changes? What are the legal limits to when to perform a new TO call? If there are no limits, it doesn't make sense to always do the performance with actual condition from the ATIS (like it my current airline). Would be wiser to add a bit of margin to be able to accept small changes without the need for another calculation. I'm asking what's legally correct here, any not what common sense tells you. Looking for documentation preferably. Hoping for some positive inputs
