Scale a wing by editing the xml code. Enter back into game designer and add a control surface to wing. This control surface is not scaled correctly to the wing in the designer. Enter into level and it will automatically fix itself.
Note reloading the designer also fixes the problem.
I'm not sure if this is what you're already doing but try to change only one axis (I think it was y axis for wings). You can make them thin without changing the profile of the wing by typing something like "1,0,1" in the tinker scale xml attribute. That would make it so thin it will be invisible if viewed from the front. You can use values over 0 to play with the desired thickness.