I haven't seen any replies to this question, so I'll give my opinion and reference the testing I've done. Please refer to http://jscott.comlu.com and follow the link to the KR page. There's a lot more detail there.
I flew my KR with the stock 72" tail for 500 hrs. Then I cut the tail off and built a 96" span tail using the 0009 airfoil provided on Mark's web site. I've flown the plane another 300 hours since then. I can't think of any other KR that has flown with both tails. In short, the additional tail horizontal stab adds significantly to the pitch stability of the plane. It is a rock solid hands off flyer when properly trimmed. Map folding or shifting around in the seat is no longer an aerobatic experience. It also added significantly to the control pressures, (also refered to as control or pilot feedback). No more super light stick that is easily over controlled. It is still very light and quick as compared to a certificated aircraft, but has a significant feel to the stick. It has a good feel to it at slow and cruise speeds, and the elevator is actually a bit heavy when the speeds get up around 200+ mph, which, in my opinion, is a desirable feature. I've been told that I wasted my time, was ruining the "sporty" feel of my KR, and that I had no idea what I was doing. But I don't know of anyone else that has done the same testing and can discuss or demonstrate the results. FWIW, I also added to the cord of the rudder, which also made a significant improvement to the ability to slip the plane and made a big improvement to the crosswind landing capability of the aircraft. Jeff Scott Los Alamos, NM On Thu, 15 Oct 2009 18:00:27 EDT bdazzca...@aol.com writes: > Hey netters, > > I was just curious on how long people are making their > elevators. > I think I made mine 84" and that's including 5" each side for the > balance > tabs. Is this too excessive or about right for stability? > > > > David Swanson > _______________________________________ > Search the KRnet Archives at > http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html > > ____________________________________________________________ Best Weight Loss Program - Click Here! http://thirdpartyoffers.juno.com/TGL2141/fc/BLSrjpTFoYeqghmZGvLlr9rXyjTgGoDI5xvzT2NPFF8SK9xnQJFs5PFamKc/