Aircraft control surface (1), in particular for an aircraft lifting surface (2), that comprises a primary control surface (6) that comprises a hinge axis (10), and a secondary control surface (7) that comprises a hinge axis (11), with the secondary control surface (7) rotating by means of its hinge axis (11) relative to the primary control surface (6), said secondary control surface (7) only partially occupying the span of the primary control surface (6), the length of the secondary control surface (7) along its hinge axis (11) being significantly less than the length of the primary control surface (6) along its hinge axis (10), and moreover the width or chord of said secondary control surface (7) along the direction of its hinge axis (11) narrows significantly towards the tip of the lifting surface (2) according to a law of narrowing designed expressly for adapting the distribution of torsional stiffness along the span of the lifting surface (2) to the distribution of aerodynamic load thereon, whereas the distribution of effective curvature due to the deflection of said control surface (1) is such that it increases the stalling angle of the lifting surface (2).