Alright, I see, the problem was I'm an idiot. In my defense, it's a little odd that airwrench works backwards from a few of its parameters while developing others procedurally, but I guess it makes sense given what the program can and can't reasonably know. Got it figured out. Once I'm through with the FSX version of this I think I'll make an X-plane version as well; I'm curious to see how closely a blade element model resembles the .air I came up with, and will post results when I get to that. In the interest of helping out googlers from the future, my issue had to do with inadvertently forcing airwrench to create dynamics for an unreasonably slow airplane because I was under the impression that the top speed variables were procedural like the stall speed variables. They are in fact static targets that airwrench adjusts induced drag (and possibly other things) to meet.