What behavior indicates the balance condition of a control surface during static rebalancing?

When assessing the balance condition of a control surface during static rebalancing, observing the behavior of the trailing edge when the surface is suspended provides vital insights. In balance, as the control surface is moved, the trailing edge should remain stable and not flutter or deviate significantly. This indicates that the aerodynamic forces and gravitational forces are well-aligned, allowing for smooth and controlled movement.

A stable trailing edge means the control surface is correctly balanced about its hinge line, which is essential for maintaining effective control authority and responsiveness during flight. Any instability or movement of the trailing edge could suggest imbalance issues that may affect the aircraft's handling characteristics.

The position of the leading edge does not directly reflect the balance condition in the same way as the trailing edge's behavior, and the rigidity of the surface is more a measure of construction integrity rather than balance. Meanwhile, sounds produced during movement might indicate issues, but they do not provide a clear, visual understanding of balance status. Therefore, evaluating the trailing edge's behavior serves as the most accurate indicator of the control surface's static balance condition.