What it is
Rotation is a change in orientation — the aircraft's attitude changes — without necessarily changing the position of its center of mass. Every point on the aircraft traces an arc around the axis of rotation.
This is the counterpart to translation. A pure rotation has no translational component; a pure translation has no rotational component. In practice, inputs produce both.
The three rotational axes
| Roll | Rotation about the longitudinal axis (nose-to-tail). Tilts the wings. |
| Pitch | Rotation about the lateral axis (wingtip-to-wingtip). Raises or lowers the nose. |
| Yaw | Rotation about the normal (vertical) axis. Swings the nose left or right. |
Body axes vs. fixed axes: An aircraft's rotational axes are attached to and rotate with the aircraft — they aren't fixed in space. That's why complex maneuvers like rolling during a climb can produce counterintuitive motion: the axes themselves are moving as the aircraft rotates.
Why pilots control rotation
Control surfaces — ailerons, elevator, and rudder — produce aerodynamic moments about the aircraft's axes. A moment is a rotational force. By commanding these surfaces, a pilot directly commands rotation about each axis, and the translational motion of the aircraft through space follows as a consequence.
Related terms
- Degrees of Freedom — the full framework of six DOF
- Translation — the other three DOF
- Axes — roll, pitch, and yaw as named axes of the aircraft