yaw dampers usually consist of a yaw rate sensor (either a gyroscope or angular accelerometer), a computer/amplifier and a servo actuator. the yaw damper uses yaw rate sensor to sense when the aircraft begins a dutch roll. a computer processes the signals from the yaw rate sensor to determine the amount of rudder movement that is required to dampen out the dutch roll. the computer then commands the servo actuator to move the rudder that amount. the dutch roll is dampened out and the aircraft becomes stable about the yaw axis. because dutch roll is an instability that is inherent to all swept-wing aircraft, most swept-wing aircraft have some sort of yaw damper system installed.