What is the primary function of trim tabs in an aircraft?

The primary function of trim tabs in an aircraft is to reduce control pressures. Trim tabs are small surfaces attached to the control surfaces of an aircraft, such as the ailerons, rudder, and elevator. Their purpose is to assist in maintaining the desired flight attitude without requiring constant input from the pilot on the control yoke or stick.

When trim tabs are adjusted, they create a small aerodynamic force that counteracts the control pressures needed to maintain a certain attitude. This allows the pilot to fly the aircraft with less effort and can enhance overall comfort during flight by reducing fatigue. The ability to relieve the pilot from holding pressure on the controls is especially valuable during long flights, as it helps maintain stable flight with minimal manual effort.

Other functions like increasing speed, changing altitude, or turning the aircraft are accomplished through primary flight controls and not through trim tabs, which are specifically designed for reducing the workload and improving control stability.