What does the turn indicator show when aileron and rudder movements are coordinated during a turn?

The turn indicator is an essential tool used by pilots to assess the coordination of a turn. When aileron and rudder movements are properly coordinated during a turn, the ball in the turn coordinator's curved tube stays centered. This indicates that the aircraft is in a balanced state, where the lateral and vertical components of the aircraft's movement are aligned, and there is no unnecessary slip or skid.

A centered ball suggests that the forces acting on the aircraft are balanced, allowing for a smooth and controlled turn. This is important for maintaining optimal performance, as any imbalance could lead to an inefficient turn or potential loss of control. Therefore, a centered ball reflects proper coordination, leading to a safer and more efficient flight.