Auxilary Rotor

A small rotor on the tail of a single-main-rotor helicopter which produces a force to counteract the torque of the main rotor. The pitch of the blades of an auxiliary rotor may be controlled by the pilot to rotate the helicopter about its vertical axis.

A rotor that serves either to counteract the effect of the main rotor torque on a rotorcraft or to maneuver the rotorcraft about one or more of its three principal axes.