In reference to the elevator, in which direction does a servo trim tab move?

• A. The same direction.
• B. The opposite direction.
• C. Upward for up elevator, downward for down elevator.
• D. It does not move.

Answer: (B)

Servo trim tabs move opposite to the elevator to generate the aerodynamic moment that helps hold the elevator in a desired position with less pilot effort. When you command the elevator to move up (trailing edge up), the trim tab deflects downward; this creates a force on the elevator that assists the upward movement and helps maintain the attitude. Conversely, when you command the elevator to move down, the trim tab moves upward. This opposite deflection is how trim tabs reduce the force required to control pitch and keep the aircraft trimmed.