What is a spring tab?

• A. An auxiliary control designed to aid the movement of a primary control at high speeds when forces become too high.
• B. A device to dampen oscillations in the landing gear.
• C. A device to measure control surface travel.
• D. A type of trim tab used only on canards.

Answer: (A)

A spring tab is a small auxiliary tab mounted on the trailing edge of a primary control surface and biased by a spring to assist movement. When the pilot moves the primary control, the spring tab deflects in a way that, through the tab’s aerodynamic interaction, helps push the main surface through its range of motion. This reduces the force the pilot must apply, which is especially helpful at higher airspeeds when control loads are large. It’s not used for damping landing gear oscillations, not a device for measuring control travel, and not a trim tab limited to canards.