Netters Couple of points to remember about the flight attitude of any aircraft. The angle of incidence is one of the factors effecting the fuselage orientation to the relative wind, BUT not the only one. In the little KR it possible for the incidence to be correct, but with an aft CG as is so common with them, you are already applying alot of down stick to hold the nose down, which is producing supplemental lift at the tail, which makes for even lower angle of attack or even more nose down. Even in larger aircraft like the Piper Seminole, the flight attitude is very different when we have people in the back seat, over when we fly with just 2 up front. Commercial aircraft use these principles to their advantage to fly faster and farther, but limits must be respected. We have less area to play and still stay safe. You could set you incidence angle to 0 degrees and if you have a rearward CG may still find yourself cruising nose down due to the other factors of aerodynamics present. Just as building a successful engine for a particular application is a coordinated package, so is the design of an aircraft. The whole package needs to coordinated for best results.
Also be careful of changing the amount of washout on the wings. This determines among other things where the stall begins first on the wing. If you have a KR2 without flaps, and full span ailerons, it is not as big a deal, but if you move the ailerons outboard as Mark L did to make room for flaps and such, then it will make a difference. If the stall begins equally out and inboard, or more out then in, the stall can be more abrupt by the time you really feel it, and loss of aileron authority will happen sooner. This can make control very sticky at the stall. More importantly it will make the control just prior to the stall more difficult, since the aileron relative wind is now more turbulent than the inboard wing root. Changing the diehedral will cause an associated loss in stability laterally. The diehedral has a way of making the CG sit lower between the wings causing the stabilizing effect of a pendulum hanging below the wing, used very successfully by the high wing crowd. It will also reduce the wing clearance available during cross wind landings, bringing the tip closer to the ground when banked into the wind. With the shorter geared KRs out there this is a big deal, especially the retracts. Just some thoughts while waiting on the FAA...... Colin & Bev Rainey KR2(td) N96TA Sanford, FL crain...@cfl.rr.com http://kr-builder.org/Colin/index.html
