There are variations but this is the basic procedure. The wing is molded complete with the ailerons. After removal from the mold the aileron ends and the bottom skin hinge line is cut. The top skin is not cut and acts as the aileron hinge. There is usually a sub spar in front of and behind the hinge line, far enough away to allow the top skin to flex. These spars and torque rods if required, are molded in before the wing halves (Top and bottom) are joined.

Ed S