Abstract: A horizontal axis wind turbine assembly adapted for use atop a tower includes a frame, a yaw shaft assembly coupling the frame to the tower, an alternator secured to the frame, a shaft coupled to the alternator to produce electrical power, a rotor hub coupled to the shaft, a plurality of blades secured to the rotor hub, and a tail assembly rotatably coupled about a vertical axis to the frame. The tail assembly is operable to move to a first, straight position aligned with the horizontal axis, and a second position rotated an angle ? from the horizontal axis. An actuator is secured to the frame and is adapted to rotate the tail assembly the angle ? from the horizontal axis.