@ Mike
Sorry, my mistake, it's a OS.60 SF 2-stroke, the one before the FX-types came out.
well, what you wrote about knife edge performance is what I expect from seeing the plans. But on this forum I read several times that a kaos can do every pattern figure without any problem (for me this includes knife edge and other figures where the rudder must be used). So this is not. Maybe I have to look for something different. The Kaos just got my attention because it's such a simple design so it would be easy to build.

@8178
I have also a plan of a kwik fli,... but it seems to me that a Kaos has a tapered wing and a Kwik fli not. correct me if I'm wrong.