Way back in the stone age (70's) when I first started flying pattern Jim Kirkland published an
article in Model Airplane News about designing and flight trimming a pattern plane. It was the
best article I ever read. I wish I could find a copy now. One of the things he was specific about was
the difference between flat and airfoiled stabs. He stated and I agree that an airfoiled stab has more
control around neutral. With a flat stab there is a dead spot around neutral where small inputs have
no effect. His experiments also showed the shape of the airfoil was not that important so he used a
diamond shape which could be built on a flat building board - no warps ! I lost my #1 plane and built
the replacement with the airfoil stab and the difference was very noticeable especially during landing.
I think most people use the flat stab just because it is easier to build.

tommy s