The forces of the wind on the airplane can also be treated as one force acting through a point called the "center of lift."

Get a large fan. Hold the body of the plane loosely between two fingers with the nose of the plane pointing toward the floor. Then move the plane into the blast of air from the fan. There is only one place that you can hold the plane so that it will balance against the wind.

Move your fingers along the body of the plane until you find the point at which the plane remains exactly vertical. (That is, pointing up and down).

Mark this point, which is the center of lift. No matter how thick the airplane is, the air only pushes on the bottom layer, so the shape of the plane controls the center of lift.