yaw

Yaw refers to the rotation of an object about its vertical axis. In most technical contexts, the vertical axis is the z-axis in a coordinate system that follows a right-handed convention, with yaw describing changes in heading relative to a reference direction. Yaw is one of the three principal Euler angles used to describe orientation, the others being pitch (rotation about the lateral axis) and roll (rotation about the longitudinal axis). The yaw angle is commonly denoted by ψ, and the instantaneous yaw rate by r, the angular velocity about the vertical axis.

In aviation, yaw is largely controlled by the rudder and interacts with roll and sideslip; sustained yaw changes alter the aircraft's course. Yaw stability and damping are important for coordinated flight, and aircraft employ yaw dampers to suppress oscillations. In ships and submarines, yaw is the turning about the vertical axis; rudders or thrusters produce yaw moments to change heading.

Measurement and dynamics: yaw angle is part of Euler angles; yaw rate r is measured by gyroscopes in inertial sensors and integrated to estimate heading. Sideslip angle beta describes sideways path relative to velocity and affects yaw dynamics. The yaw response depends on geometry, speed, air or water density, and external factors such as crosswinds or current.

Applications and context: yaw is important in navigation, vehicle dynamics, robotics, and stabilisation systems. Uncommanded yaw can arise from crosswinds, rudder misalignment, or hydrodynamic effects; appropriate control laws and dampers mitigate such effects. The term is also used in reference to animal movement and computer graphics, where yaw describes rotation about a vertical axis.