Gapped trailing-edge control surface for an airfoil

The present invention relates to airfoil assemblies such as wings or stabilizers having movable control surfaces such as ailerons, flaps, elevators, and the like. The invention relates more particularly to such a control surface that is designed to create an air flow slot between the control surface and the fixed airfoil to which it is attached when the control surface is deflected away from a nominal position, so that air can flow through the air flow slot and thereby reduce the tendency for air to separate when flowing over the deflected control surface. An airfoil assembly, such as a wing or horizontal stabilizer, has a gapped trailing-edge control surface and a door connected to the control surface by a linkage such that deflection of the control surface in one direction causes the door to pivot, thus opening an air flow slot for air to flow through. The air flow slot begins to open immediately with deflection of the control surface from its nominal position, thus establishing a desirable level of air flow to suppress separation on the control surface. The linkage connecting the control surface to the door is free of rolling or sliding elements, consisting exclusively of members pivotally connected to one another.