semi-symmetrical airfoil
The airfoil is the shape of the wing’s “thick” axis. It is the “depth” dimension of the wing. There are three types of airfoils used along this axis. The Flat Bottom airfoil has a straight bottom with a curved top. The Symmetrical airfoil has the same curve top and bottom. The Semi-Symmetrical airfoil has a fully curved top and a partially curved bottom that is a mix of a straight flat bottom with some curvature.
