I have a Great Planes Cap 21. It is a great looking plane. It is powered by a ST45, Pitts muffler. I just flew it again this past weekend, and I'm amazed all over again, just as I am every time I fly it, at how badly it flys. I know it has earned the nickname, "Snap 21", but I can't figure out why it flys the way it does. I tinkered with installing the FMA auto pilot on it last week, and while it may tame it in the air, landings will still be fatal. It is almost required to land at 3/8 throttle to avoid cartwheeling. Unfortunately, my last landing was a little less than 3/8 throttle, and after cartwheeling, it hit the spinner so hard it broke the motor mount.
In the air trying to do loops without having it "snap" out on top takes a really light finger. I set low rates so low you had to look twice to see if the elevator was in fact moving. I also set exponential at 67%. One out of five loops will complete without snapping out and "hunting" the ground.
I'm not the best pilot in the world, but I have always been able to land anything. that is until I met up with this Cap. Anyone have any similar experiences?