Hi, After getting the brakes to work smoothly and completing my biannual flight check the day before, I tried the first flight test of my KR2S conventional gear with Jabiru 2200. It was a good day with a steady headwind of about 10 mph right down the 6000? runway. The plan was to take off and fly along at 20 to 30 feet and then land. I got off the ground quickly at about 75% throttle. I expected that I would have had to apply some back pressure to the stick to lift off and climb but did not.
The plane nosed up and climbed to 30 feet or so, then slowly nosed down some to about 20 feet then the nose started back up. This happened like 3 cycles. All the time I am holding the stick as steady as I could in pitch, not wanting to aggravate the situation and get into PIO. I felt no feedback stick pressure either forward or backward. I reduced power slowly and lost altitude until it felt safe to flare. Then I reduced power and slowly applied back pressure. The pitch oscillations continued. I could not hold a steady pitch angle as I flared. The landing was in a word wild, but successful. I can attest that the gear is rugged. The plane never felt like it was going to stall. It just settled. With no feedback pressure, it basically felt as if I had no control. The safety person watching is a pilot and said it looked just like one of his radio controlled models he flew that was tail heavy. The next day, we did a weight and balance with 6 gal of fuel in the header tank and myself in the plane just as it was during the flight. The cg was 12? aft of the wing leading edge, the center of the range. The empty weight is 640 lbs. I can add 20 lbs of weight right behind the engine but it will only move the cg to 10.93? aft of the L.E. As fuel burns off, some of that gain would be lost. If I add 40 lbs to the front, the plane will probably fall on its nose when I get out. The control cables from the bellcrank behind the rear spar to the elevator are tight. There is a small amount of play where the control stick mounts in the cross tube which connects to the bellcrank via a push pull tube. Because of the looseness at the bottom of the stick, the top of the stick can move at the most 1/8? for/aft before the elevator moves. I have a feeling that I am overlooking something and I hope to receive some comments that will help explain what happened and some ideas for a reasonable remedy. At this point, it appears that it is a cg problem. I am 5? 10 ½ ? and weigh 190 dressed for the flight. Losing 40 lbs would be good, but probably not realistic. If the plane is that sensitive to cg location, it looks like carrying fuel in the wing tanks or any luggage would be out the question. Dan
