On Sun, Feb 22, 2015 at 1:29 AM, Flesner via KRnet <krnet at list.krnet.org> wrote: > >> >> The Spreadsheet says we should be using aluminum spars to make more >> than 2G load factors. > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > It's been a long held belief that the WAF's were the weak point in the KR > spars. I've had the opportunity to inspect 3 crashed KR's, unfortunately
both front and rear spars together can easily take 3.8G at 1200 lbs mtow. but thats a rough calculation. i'm actually overestimating the stresses because tapered wings have more or less 10% lower bending moments than rectangular wings overall. I was assuming a rectangular wing. a more accurate computation will require more accurate load distributions with flap and aileron deflections considered. only shrenk's approximation and similar procedures can do that.
