Which trim tab is known as the anti-servo?

The anti-servo tab is known primarily for its function in relation to the elevator. It is designed to increase stability and prevent over-controlling in the pitch axis of an aircraft. When the pilot moves the elevator control, the anti-servo tab moves in the opposite direction, providing a resistance force that helps the pilot maintain better control, especially during maneuvers that could otherwise lead to excessive or abrupt pitch changes.

This tab enhances the aerodynamic stability of the elevator, making it harder to push the nose up or down too quickly, which is particularly useful during high-speed flight or when making sensitive adjustments. The additional aerodynamic forces from the anti-servo tab can also serve to warn the pilot that they are approaching the limits of control response.

Other control surfaces such as the rudder, ailerons, and flaps may have their own functions and tabs, but they do not perform the specific role of an anti-servo tab in the same way that the elevator does.