Dene Collett wrote: > I am using the AS5048/5045 combination . I know these airfoils > were designed to be a direct replacement for the RAF48 but I am not sure if > the CG limits are the same.
Since you mention 4130 tubing, I'm assuming you're thinking about nose gear. I don't know that anybody has done a "real" analysis of the KR2S (and exactly which variation, since they're just about all different), especially with the new airfoil. But for the purposes of KR gear construction and location, I personally would (and have), considered the difference between the RAF48 and the AS504x to be minimal, with respect to almost anything but drag. I don't claim to be an aerodynamicist, however...so somebody that IS and wants to take a look at this and be more specific is certainly welcome to it. It should be mentioned though that in my mind, there are just too many variables for anybody to come up with a good solid answer to your question, at least with enough accuracy to hang your hat on. If you build it like what everybody else has built (using the RAF), you won't be any farther off than they are, I'll bet. Don't forget that both analysis AND experience have proven the aft 2" of the published CG range is an unstable area that is best avoided, so I'd build it to keep the range centered in a 6" range, rather than the 8" range. But I've probably said that before, which is why you asked the question again, so I'll just wait for that "more educated" reply to your question (if it ever comes). And if yours is a basic question about tri-gear location, I'm clueless anyway, having never paid much attention to it, using either airfoil... Mark Langford, Huntsville, Alabama see homebuilt airplane at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net
