ORIGINAL: Balsawings
Cees,
You've got it backwards. Look at any good set of plans that shows incidence, you'll see negative is leading edge down.
The reason for the +.3 wing and -.3 on the stab is simple. A truly symmetrical wing will not fly at 0 degrees. It has to have a positive angle of attack before it will create lift. If you set a plane up 0 - 0 you will have to use up elevator trim to creat the positive angle of attack.
Bob
Ah, but you have missed an important, somewhat secret, point. If a model is set up trimmed for an initial zero-zero incidence between the wing and the horizontal stab and then balanced slightly tail heavy, the tail heaviness will provide enough positive incidence to the entire airframe for it to fly level both upright and inverted. Ever wonder how guys got their models to do that?
Ed Cregger