What is the term for the movement of a plane on the vertical axis?

The term for the movement of a plane on the vertical axis is known as "Yaw." This movement occurs when an aircraft rotates around its vertical axis, which runs perpendicular to the wings and to the ground. Yaw is controlled by the rudder, which is located on the vertical stabilizer (the fin) at the tail of the aircraft. When the rudder deflects to the left or right, it causes the airplane's nose to move left or right, allowing for coordinated turns and adjustments in direction during flight.

Understanding yaw is crucial for pilots as it directly relates to the aircraft's directional control and stability during maneuvers. For instance, during a turn, yaw needs to be coordinated with roll (the tilting of the wings) to maintain a balanced and effective flight path.