Which instrument measures lateral movement of the aircraft?

The turn coordinator is designed specifically to measure the rate of turn and the coordination between the aircraft's lateral movement and its banking angle. It provides vital information on how the aircraft is turning and whether the turn is balanced or uncoordinated. By displaying the rate of turn in degrees per second, it allows pilots to maintain a proper rate for maneuvering and can indicate when the aircraft is skidding or slipping during a turn.

While other instruments play significant roles in navigation and orientation, they do not specifically measure lateral movement. For example, the heading indicator indicates the aircraft's direction relative to magnetic north, but it does not provide direct information about lateral movement during a turn. The vertical speed indicator shows changes in altitude rather than lateral dynamics, and the attitude indicator reflects the aircraft's orientation in relation to the horizon but does not measure lateral movement or turn rate directly. Thus, the turn coordinator uniquely fulfills the requirement to assess lateral movement in flight dynamics.