Thanks for that Tony,
Have you tried any other vertical surface increasing devices on the rear of the plane? I'm thinking winglets or small additional mid span fins that have been added to some full size aircraft with yaw stability problems. Float equipped DH Beaver and Fairey Gannet contra equipped spring to mind. Trying to decide best way of improving the yaw stability of my Contra equipped Asyuler. Temporary fences seem to have helped but was just wondering if there is a better way?
Malcolm