ok well then i am curious if he uses these calculations exclusively why would he care about the weight discrepancies you posted?
If you look at, for example, CFD simulation, you need to know the geometry of the body for which you're trying to get state variables. For example, you could map a pressure distribution on a body (in any state of control surface deflection) in a known flow using CFD. That particular map, however, would only tell you the flight behavior of the AC after you'd resolved it out and effected it to the vehicle (i.e. distributed-mass body in grav field). For that, i'd turn to a rigid or elastodynamic sim like ADAMS (what I used to do) or even classical analytic methods and you'd need additional properties of the a/c - like its mass distribution cited -to get the flight behavior. ADAMS, btw, was notoriously difficult for soing something like a flight vehicle because it didn't handle continuous things like a fluid flow well. It was another story if you had some sort of analytic representation of the forces that you could input as a user-defined force based on in-sim variables.
Here's the thing, though, Thor... it IS entirely possible to do virtual "testing" with the right level of analysis and specific input properties for the AC - and you might even get it right if you've done a couple of correlations with your method and know it's pitfalls. This stuff isn't the black box I think you might imagine it to be... i.e., HTC does do this crap for a living (lucky bastard) and, based on what I've seen, does it pretty well. I speak as an Aero Engineer who used to do tunnel tests at NASA Ames. While I haven't done Aero for something like 20 years (I went over to Automotive and used to do vehicle dynamics - sim, test, and correlating the two - there before crossing to the "dark side), I've been around engineering, its methods, and other technical crap long enough to have a pretty keen BS detector - and it ain't going off in response to HTC's posts.
All that said, that's why I want to see more. Until you understand his methodology, you're really unqualified to critique it in anything more than an uninformed way. Clearly, there are different degrees of "uninformed-ness". You might want to learn a little something about some of the methods to which this group of self-congratulatory, somewhat grating, but generally intelligent and oddly enjoyable arscheklownen have linked, then come back with better questions. That's what I'm going to do - because besides the CFD and FEM stuff, there were a couple of more specific items cited that should prove informative.
