a section of control surface which projects ahead of the pivot point

An arm fastened to a control surface to which is connected the control rod.

Control horns are used to give movable control surfaces movement. A push rod is used to connect a servo to a control horn (via a clevis or z-bend in a wire). The control horn is attached directly to the surface and can be made of nylon (best for combat sailplanes), or wood or metal. Store-bought control horns usually have several holes for connecting the push rod. Holes nearest to the control surface give the surface more movement.