Originally Posted by
Starbear
I recommend downloading “Getting to Grips with Performance” an Airbus publication and start at section C 7 Flexible and Derated Takeoff and careful study should answer all of your queries.
You may then be tempted to explore this document further for more gems.
SB
I'm familiar with that document, and it doesn't explain what I'm asking. It just states that this is the case, but not why this is the case.