Definition
Rotation of the airplane about its vertical axis, causing the nose to move left or right. Yaw is controlled primarily by the rudder.
Plain English
Yaw is when the airplane's nose swings left or right, like turning your head from side to side without tilting it.
Context Anchor
You will see yaw when learning the airplane’s three basic motions, using the rudder, and keeping the airplane coordinated in flight.
Derivation
From an old nautical term meaning to deviate or wander off course. Originally used for ships swinging off heading, the word carried over to aircraft to describe the same kind of side-to-side movement of the nose.
Why Pilots Care
Uncontrolled yaw creates slipping or skidding, increases drag, and can lead to loss of directional control, especially during turns or engine power changes.
Analogy
Yaw is like turning your head left or right while your body keeps moving forward. The direction your nose points changes, even if your overall path has not fully changed yet.
Intuition Check
Yaw is not the same as a complete turn. Yaw is the nose moving left or right; a proper turn also involves the airplane changing its flight path.
Example Sentence 1
When the pilot pressed the right rudder pedal, the nose yawed to the right.
Example Sentence 2
In a coordinated turn the pilot keeps yaw to a minimum by matching rudder pressure to aileron input.