An airfoil body for an aircraft extending from an inner end to an outer end, between a leading edge and a trailing edge and having a pressure surface and a suction surface, the airfoil body having an outer surface and an inner support structure, the outer surface including a fixed skin section and a movable skin section, wherein the movable skin section comprises a first portion including an array of transducer elements, and the airfoil body including an actuator for moving the movable skin section to selectively position the transducer elements on the outer surface.