Definition
Automatic flight control devices that sense unwanted yawing motion and apply small, rapid rudder corrections to suppress it, particularly the combined yaw-and-roll oscillation known as Dutch roll. They are commonly fitted to swept-wing jets and many turboprops where natural directional stability is reduced.
Plain English
A small automatic system that nudges the rudder back and forth on its own to stop the airplane from wagging its tail or rocking side to side.
Context Anchor
Seen in discussions of Dutch roll, swept-wing airplane stability, autopilot systems, and flight-control checks.
Derivation
Yaw is the side-to-side rotation of the nose around the vertical axis. To damp something means to reduce or quiet a motion, in the same sense as a shock absorber damping a bounce. A yaw damper, then, is a device that quiets unwanted yawing.
Why Pilots Care
Yaw dampers maintain comfortable, stable flight by preventing Dutch roll, which can grow pronounced in swept-wing jets at altitude.
Grounding Statement
If the airplane’s nose starts wagging left and right after a disturbance, yaw dampers add small rudder corrections to settle it down.
Intuition Check
Yaw dampers do not stop the pilot from turning the airplane. They reduce unwanted yaw motion, not intentional control inputs.
Example Sentence 1
Before climbing into the flight levels, the crew engaged the yaw damper to suppress any tendency toward Dutch roll.
Example Sentence 2
During turbulence the yaw damper kept the aircraft on heading without noticeable side-to-side swinging.