hello guys,
thanks for your answers and explanations.
i have to say that datas are from boeing books (jar)...!!! so this is not the planning program...
no i dont know about aerodynamics but i think this is more the bleed system as i m talking in norm cruise not specific transport...
now i can say that is from a classic side (i just dig from others manuals) that boeing made a good design for -300 but the weight is worst (more metal is more to carry...)
742 GE 320/.82
climb 370T fl 310 27' 10150 kgs 167 nm
cruise 360T .84 14272 kgs/hr 492 tas tat -15
743 GE 330/.83
climb 370T FL 310 25' 9800 kgs 154 nm
cruise 360T .84 13508 kgs/hr 492 tas tat -15
so with same result but inverse we can extrapolate that this is ccertainly some engine extraction that can cause this difference as the speed is better for LRC on the -400 versus -400F ???!!!
thanks for your attention and more help
truly yours
phil