A lifting airfoil (10) includes a landing flap (20) movably connected to a main airfoil body (10') so as to form at least a portion of the trailing edge of the airfoil. The landing flap (20) includes a leading edge nose (21) and a trailing edge body (22), which are each bounded by an upper cover skin (23) and a lower cover skin (24). The trailing edge body (22) is connected to the leading edge (21) by the continuous upper cover skin (23), while a gap (25) interrupts the lower cover skin (24) between the leading edge nose (21) and the trailing edge body (22). The flap (20) is mounted on a carriage (31) that moves along a guide rail (30) so as to be slidably and pivotably extendable during take-off and landing phases of a flight. Furthermore, the trailing edge body (22) is elastically flexible and can be deflected as needed for adjusting the camber thereof during cruise flight by operating an actuating device (29) that is pivotably connected between a trailing edge area of the trailing edge body (22) and the guide rail (30).