Question

Primary purpose of trim tab is to

• A. Ensure that the total moment about the center of gravity equals zero
• B. Increase lift
• C. Make the total drag equal to zero
• D. Decrease lift

Hint:

A trim tab is used to \[ \boxed{ \text{balance aerodynamic moments and reduce pilot effort.} } \] During trimmed flight, \[ \boxed{ \sum M_{CG}=0. } \]

Answer 1

The Correct Option is A

Step 1: Recall the purpose of a trim tab. A trim tab is a small adjustable control surface attached to the trailing edge of a primary control surface. Its purpose is to reduce the pilot's control force by balancing the aerodynamic moments.

Step 2: Identify its primary function. During trimmed flight, \[ \boxed{ \sum M_{CG}=0, } \] where \[ \sum M_{CG} \] is the total moment about the aircraft's center of gravity. Thus, the trim tab helps maintain equilibrium without continuous pilot input. Therefore, \[ \boxed{\text{Ensure that the total moment about the center of gravity equals zero}} \] is the correct answer. Thus, \[ \boxed{(A)} \] is the correct answer.