Definition
A short lever attached to the edge of a flight control surface (such as an aileron, elevator, or rudder) that provides the attachment point for the control cable, pushrod, or actuator. The horn converts the pulling or pushing force from the control system into rotational movement of the control surface around its hinge line.
Plain English
A small arm sticking out from a moving control surface that the cables or rods connect to. When the cable pulls on the arm, the surface swings up or down.
Context Anchor
Seen during flight-control inspections, rigging, and maintenance of ailerons, elevators, rudders, trim tabs, and similar movable parts.
Derivation
Called a 'horn' because the lever projects out from the surface like a small horn from an animal. The shape gives the control system leverage to move the surface.
Why Pilots Care
Secure, correctly rigged control horns deliver accurate response from control surfaces; damage or looseness can reduce control effectiveness or cause flutter.
Analogy
Like the handle on a door. The door swings on its hinges, but the handle gives you something to push or pull on to make it move.
Intuition Check
Do not read horn here as a sound-making horn. In this context, a horn is a projecting arm or bracket that transfers motion and force.
Example Sentence 1
During the preflight inspection, the pilot checked that the control horn on the rudder was secure and free of cracks.
Example Sentence 2
The aileron pushrod bolts directly to the control horn to convert cockpit stick movement into wing roll.