I don't think my earlier response was posted so here it is again...plus a graphic of how the cg limit shrinks with wingspan on the KR2S. Something that is worth considering is the washout. The graphic shows the cg range in steady flight...as you approach a stall, the washout allows the inboard part of the wing to stall first and the outboard part of the wing is still flying. This moves the MAC further outboard and further shrinks the c.g. range. If you are on the ragged edge of the aft c.g. before the stall, you might be completely unstable in the stall. This could be part of the reason why the aft 2 inches is a danger zone.
I agree with that assessment...the point I was trying to make is that it doesn't appear that the mac was ever recalculated for the kr2s. The mac in the plans are for the kr2....not the kr2s. What makes matters worse is I tried to recreate the mac in the plans and couldn't get it to correlate so I suspect it is just a carryover from the kr1 plans. This is essentially a tapered forward swept wing....the longer the span the smaller and more forward the mac and the corresponding cg range. The forward limit is only limited by the amount of elevator...a bigger elevator and you can move the forward limit. The aft limit is the death zone...the aircraft becomes unstable. It is essential that you keep forward of the aft limit...but does anyone really know what that aft limit is? On Aug 16, 2013 5:33 AM, "Mark Langford" <ml at n56ml.com> wrote: > The aft two inches of the CG range for KR2 or KR2S is a danger zone. > Early fliers realized this and sent out the warning via the Newsletter, > but Richard Mole, English Aeronautical Engineer, studied it in detail and I > believe his comment was something like "I hope nobody's tried to fly it > like that". There have been several folks who didn't live to spread the > word. I accidently flew with an aft CG, and detailed the experience at > http://www.n56ml.com/wb/index.**html <http://www.n56ml.com/wb/index.html>. > It's not something you want to repeat! Err on the side of a more forward > CG, especially during initial flights. The speed difference is not > noticeable. > > Mark Langford > ML at N56ML.com > website at http://www.N56ML.com > ------------------------------**-------------------------- > > > ______________________________**_________________ > Search the KRnet Archives at > http://tugantek.com/**archmailv2-kr/search<http://tugantek.com/archmailv2-kr/search> > . > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see > http://list.krnet.org/mailman/**listinfo/krnet_list.krnet.org<http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org>to > change options > -------------- next part -------------- A non-text attachment was scrubbed... Name: cg vs planform.jpg Type: image/jpeg Size: 71423 bytes Desc: not available URL: <http://list.krnet.org/mailman/private/krnet_list.krnet.org/attachments/20130816/57a24931/attachment.jpg>
