What is the purpose of trim tabs?

The purpose of trim tabs is to maintain the desired flight attitude of an aircraft. These small movable surfaces are attached to the trailing edges of control surfaces like ailerons, elevators, and rudders. When a pilot makes adjustments to maintain level flight or a specific angle of attack, they can experience a constant need for control inputs due to various factors like wind changes or weight shifts. Trim tabs alleviate this by allowing the pilot to set and hold a desired flight attitude without continuous control input.

By adjusting these tabs, the pilot can create a small aerodynamic force that counteracts any unbalanced aerodynamic moments acting on the aircraft. This results in a more stable and comfortable flying experience, as the pilot doesn't have to exert constant effort on the control yoke or stick. The correct functioning of trim tabs thus enhances the overall aerodynamic efficiency and responsiveness of the aircraft.