A rotary hydraulic actuator may be configured to output rotary motion to control a hinged surface of an aircraft. The actuator includes a nested ballscrew, ballnut, and output assembly that form concentric ball races for converting the linear motion and force of the linear actuator to rotary motion and torque of the output assembly that is connected to the hinged surface. One of the ball races is helically inclined and the other of the ball races is linear. The rotary hydraulic actuator may include a ball return structure that returns the balls from a loaded path of a ball race to an unloaded path of the ball race. The ball return structure may define a ball return path that is located at the same radial distance from the actuator centerline as the loaded path for minimizing the overall diameter of the actuator.