Definition
Rotation of the aircraft about its vertical axis, causing the nose to move left or right. Yaw is controlled primarily by the rudder.
Plain English
Yaw is the side-to-side swing of the nose, like shaking your head 'no.' The aircraft pivots around an imaginary vertical line running from the top of the cabin down through the floor.
Context Anchor
Seen in discussions of aircraft control, stability, propeller effects, and directional control during takeoff, landing, and engine-power changes.
Derivation
From an old nautical term meaning to deviate from a straight course. Sailors used 'yaw' to describe a ship swinging off heading, and the word carried over to aviation for the same kind of side-to-side motion of the nose.
Why Pilots Care
Uncoordinated yaw degrades flight efficiency, can lead to a slip or skid, and in extreme cases contributes to spins. Proper rudder use to manage yaw is essential during takeoffs, landings, crosswinds, and any change in power or pitch.
Intuition Check
Yaw does not mean the aircraft is climbing, descending, or banking. It means the nose is rotating left or right around the aircraft’s vertical axis.
Example Sentence 1
When the pilot pressed the right rudder pedal, the nose yawed to the right.
Example Sentence 2
During the crosswind landing the airplane showed a slight yaw just before touchdown.