I’m not a physics guru (although I did minor in physics in college). Did anyone who is working on this debate take into account that the wing of an SRX has to be modeled as 2 wings, each with differing lift and drag coefficients? Add in the complex airfoil issues of the rest of the curved composite structure and the wing cuff, and I’m willing to bet the problem is that best glide characteristics for the inboard wing section and best glide characteristics for the outboard section interact in some mathematically interesting ways. Has anyone asked Cirrus’ engineers for an answer?
Also, I had a talk with a flight test engineer from the FAA’s Atlanta Aircraft Certification Office last week. Seems he worked for NASA and the Air Force during the original development of stall-resistant wing shapes. His simplified answer to my question about wierd #s when dealing with Cirrus airspeeds (simple because I wasn’t following the math and this was a social setting) was that almost none of the “classic” formulae for aircraft performance can be appled directly to modern computer-designed complex “discontinuous” airfoils. (the old ways will get you into the ballpark, but won’t be better than 90-95% accurate.) There is math that will work, but since the engineering is complex, so is the math. He promised to send me the working papers that came out of the program, and left our conversation at …“trust the #s Cirrus provides. Feel free to interpolate, we allowed for that in the certification process, but whatever you do, don’t extrapolate…” One thing he did specifically mention was that the cuff changes the math significantly all by itself.
Again, I’m not the sharpest knife in the drawer when dealing with aerodynamics, but this is something those of you fretting about this concept perhaps should account for…
BTW, for those who think the CAPS is a far-out invention for airplanes, this guy had some interesting stories to tell about testing wing-tip parachutes and wing-tip rockets for spin recovery devices!