Yaw damper improves which stability?

• A. Directional stability
• B. Roll stability
• C. Longitudinal stability
• D. Vertical stability

Answer: (A)

Directional stability is what a yaw damper improves. It treats yaw motions about the vertical axis, damping them to keep the aircraft from skittering side to side or entering persistent yaw oscillations. A yaw damper senses yaw rate and automatically applies small rudder inputs to oppose that motion, which also helps suppress Dutch roll, a coupled roll-yaw oscillation common in swept-wing aircraft. Since roll stability concerns the roll axis and longitudinal stability concerns pitch, a yaw damper’s primary role is enhancing directional stability, making that choice the best fit.