Abstract: In accordance with the present invention, there is provided an aerodynamic control surface apparatus for use with a wing assembly having a wing trailing edge. The control surface apparatus has an inboard section defined by a cordwise inboard side, a first trailing edge side, and a first tapering edge side disposed between the inboard and the fist trailing edge sides. The inboard section has an axis of rotation generally about the cordwise inboard side. The control surface apparatus further has an outboard section defined by a cordwise outboard side, a second trailing edge side, and a second tapering edge side disposed between the outboard and the second trailing edge sides. The outboard section has an axis of rotation generally about the cordwise outboard side. The control surface apparatus further has at least one adjustable spanwise member rotatably attached to the first and second tapering edge sides of the inboard and outboard sections.