Abstract: An airfoil for an aircraft having a first surface extending between the leading edge and the trailing edge, and a second surface joined to the first along the leading edge and projecting rearwardly in the direction of said trailing edge. The second surface of the airfoil terminates materially in advance of the trailing edge to define a step-like discontinuity of the airfoil. One or more lift generating members are pivotally mounted on the second surface of the airfoil adjacent the step-like discontinuity. The lift generating members are selectively movable to various positions relative to the airstream to alter the aerodynamic forces on the airfoil during conditions of flight.