What is the primary function of a series yaw damper?

The primary function of a series yaw damper is to stabilize yaw without moving the rudder pedals. A yaw damper is an automated system that helps to control the aircraft's yaw motion, particularly in response to various flight dynamics, such as turbulence or asymmetrical forces. By continuously assessing the aircraft's attitude and reacting appropriately, the yaw damper can minimize unwanted yawing motions, enhancing stability and reducing pilot workload.

This system is crucial for maintaining smooth flight and contributing to overall aircraft control, especially during cruise and in adverse conditions. Unlike manual inputs from the pilot (like rudder pedal movement), a yaw damper operates automatically and ensures that the aircraft remains coordinated and stable without requiring constant pilot intervention.