What is the motion called when an aircraft rotates around its longitudinal axis?

The motion when an aircraft rotates around its longitudinal axis is referred to as "roll." This movement involves tilting the aircraft from one wing to the other, which is crucial for executing turns and maintaining balance during flight. The longitudinal axis runs from the nose to the tail of the aircraft, and when an aircraft rolls, it alters the angle of its wings relative to the horizon, allowing the aircraft to maneuver more effectively.

Pitch and yaw, while also critical axes of motion, refer to different movements. Pitch involves rotation around the lateral axis (the wingtip to wingtip axis), resulting in the nose of the aircraft moving up or down. Yaw involves rotation around the vertical axis (the top to bottom axis), which dictates the aircraft’s left or right movement. Lift describes the aerodynamic force that opposes the weight of the aircraft and is not related to the rotation of the aircraft around any axis. Thus, roll is the correct terminology for the specific motion of rotation around the longitudinal axis.