ORIGINAL: Lowlevlflyer
Yup, flying a full scale V-tail Bonanza is a bit interesting the first time you do it, especially if it's windy! That little side to side oscillation, although slight, takes a couple of flights to get used to. Once you get past that, they're great performers, especially if you're flying one that 's been injected and turbocharged!
I think that that's called "dutch roll", the plane's yaw-roll coupling causes yaw to roll the plane but then the roll creates adverse yaw which then rolls the plane the other way and repeats. Conventional tailed airplanes will do this also if the verticle fin area is too small, or so I have read in free flight trimming articles. Too much verticle stabilizer area and the plane becomes spirally unstable. The key to free flight planes is just enough verticle stabilizer area to damp out dutch roll but not enough to cause the plane to go into a spiral.