Is this the next method and the only remaining method? In this method, how did you create 6 surfaces on the upper and lower surface of the wing? Did you cut the facets of the wing by creating three planes and then create a surface on the cut facets with the skin surface tool?
Unfortunately, the end part of the wing did not become the surface. What is the solution? In this video, what shape is the wing supposed to turn into at the end?