As I wrote earlier about the first flight of my KR2S. It took off and began to climb rapidly. I was able to control the roll ok with the ailerons, but I did not feel that I had comfortable control in pitch. I was concerned about getting into pilot induced oscillations. After climbing some, the nose settled down, then came back up. This happened about 3 times and I reduced power and was able to get it back on the runway. The landing was wild to say the least. We reweighed the airplane as flown to check the cg as it acted like a tail heavy condition. The cg was fine. Then one night it came to me. I now believe that I built in the problem when I made the bottom of the cowling. The engine cowling was long because of the lighter weight of the Jabiru 2200 engine. Ahead of the wing, the bottom of the fuselage slopes upward at about 9 deg until it ends at the firewall. I continued this flat area at the same slope to the rear of the engine and then added kind of a chin behind the nose bowl where the muffler is and then tapered this chin back in width and depth. The overall effect was a large flat area under the cowl that acts as a canard inclined upward and lifts the nose. The total flat area is 716 sq in and slopes upward at 9 deg. The lever arm of the centroid of this area is 29? from the center of the cg range. The amount of lift on the canard is be dependent upon angle of attack and the speed of the air hitting it (rpm). I now know why it was so important to develop wind tunnels and train test pilots. Looking back, I wonder why didn't I think about the effect of the cowl as now it seems obvious, but that's the way life goes. We have to be vary careful about what we think we know. Dan
