What term describes the movement of a rotor blade relative to other blades in the plane of rotation, including leading and lagging?

• A. Hanging
• B. Hunting
• C. Spiraling
• D. Precession

Answer: (B)

The movement of a rotor blade relative to the other blades in the plane of rotation, including leading and lagging, is described as hunting. This describes the lead-lag motion of blades as they swing forward (lead) or backward (lag) around the hub due to aerodynamic forces and inertia, especially after a disturbance or control input. The rotor system tends to oscillate in this plane as it dampens toward equilibrium, so the term hunting captures that side-to-side, in-plane motion of individual blades relative to their neighbors. This is different from precession, which is a gyroscopic effect, or hanging, which refers to vertical flapping, or spiraling, which isn’t the standard term used for this blade-to-blade motion.