So does WAT limit come into this equation? Or is WAT limit used for performance on the ground only or through all phases of flight?
If we take various limitations of other traffic and ATC out of the equation for now..
My way of thinking was that an aircraft will climb to the altitude it gets its optimum fuel burn for that weight as calculated by the FMS taking into account various cost index inputs calculated for the day? To get the optimum SFC for the speed that it wants to fly at... So say for example an aircraft initially climbed upto FL290 because basically the FMS would have calculated that for the weight the aircraft was at that would get the speed it wanted with the most efficient SFC?
So it would not request a further climb to say FL330 until it had burned more fuel and lost more weight because if it just climbed straight up to FL330 due to the fact it is fairly heavy it would require more thrust in order to maintain straight and level than if it just stayed at FL290.. Therefore reducing the SFC? Am I understanding correctly so far?
But then considerations would have to be taken into account to the winds inthe upper atmosphere and also the temperature. So the height of the tropopause would have to be considered as to where the optimum temperature would be?
I'm not looking to get slated here just trying to learn to see if I am kind of in the right area with my way of thinking?
This is why I ask does WAT limit get considered in all phases of flight? I assume that yes it does but wasn't sure. As obviously it is very critical in take off performance if you are taking off on a shorter runway on a hot day with a high density altitude with a heavy aircraft.
I know various ATC limitations have to also be implemented but just asking from a pure performance point of view imagining there were no other aircraft in the sky.