When the elevator moves down, what direction does the trim tab move to help achieve this?

When the elevator moves down, the trim tab is designed to move up. This action assists in balancing the control forces required to maintain a desired pitch attitude.

The elevator controls the pitch of the aircraft, and when it is deflected downward to pitch the nose down, it creates a moment that must be counteracted to maintain control with reduced pilot effort. By having the trim tab move up, it generates an aerodynamic force that acts in opposition to the elevator's downward movement, reducing the pilot's workload.

This design is key for improving the aircraft's stability and overall control, ensuring that the pilot can maintain comfort and safety without needing to exert continuous force on the controls.