Definition
A coupled lateral-directional oscillation in which an airplane simultaneously rolls and yaws in opposing directions, producing a rhythmic, side-to-side wagging motion combined with a rocking of the wings. It occurs when an airplane's directional stability is weak relative to its lateral (roll) stability, and is most common in swept-wing aircraft.
Plain English
A repeating wobble where the airplane's nose swings side to side while the wings rock back and forth at the same time. The two motions feed each other, producing a steady, uncomfortable weaving.
Context Anchor
Seen in discussions of yaw dampers, especially in larger or swept-wing airplanes where automatic damping helps keep the airplane stable and comfortable.
Derivation
Named after the motion of Dutch ice skaters, who shift weight side to side in a smooth, rhythmic pattern as they skate. The airplane's combined rolling and yawing motion looks similar.
Why Pilots Care
Left undamped, Dutch roll can grow into larger oscillations that reduce passenger comfort and, in extreme cases, affect controllability.
Analogy
It is like a shopping cart with a wobbly front wheel: the cart may still move forward, but it wiggles left and right instead of tracking smoothly.
Grounding Statement
Picture the nose gently wagging left and right while the wings rock from side to side; that combined motion is Dutch roll.
Intuition Check
Dutch roll does not mean the airplane is doing a normal roll maneuver. Here, roll means wing-rocking that is coupled with side-to-side yaw.
Example Sentence 1
When the yaw damper failed, the crew noticed the airplane beginning to Dutch roll and reduced speed while requesting a lower altitude.
Example Sentence 2
With the yaw damper inoperative, the test pilot noted increasing Dutch roll amplitude during high-speed cruise.