hmm i get it, but i would also like to mention that when i use pfpx,AS2016 and topcat to plan my flights i get values that doesnt match with the values i get when i enter the numbers in pmdg 777lr, For example i have topcat saying TO1 +54  resulting 87%N1 on fmc TO1 +54 gives 95%N1.(i compensate it by changing the assumed temperature)  Having a pmdg  calculator would eliminate the accuracy differences between other products.(i remember reading in t7 update topic that they ve changed the assumed takeoff algorithms to have more realistic result) However i cant say how much it cost in time or money but given the complexity and the price range of the product i say it is worth it.

FWIW in the airppane i fly, on occasion get performance numbers that are sometimes 3% N1 off. The limiting factor is that as long as the airplane gives you an N1 setting that is equal or greater to what N1 setting the Performance planning gives you, youre good to go. If not, lower the assumed temp until its equal or greater too what the planning gives you.

And we're currently modeling a 747, right?

 

Are you really!? Well um ...when is that happening?