A wind turbine includes a quartet of pivot shafts in paired parallel relationship and transversely mounted on a central drive shaft, each pivot shaft supporting a pair of wings at opposed ends thereof, the wings offset by 90°. Each pivot shaft rotates cyclically through 90° to move each wing from a wind-engaging orientation (drive position) in which the wing presents a flat surface approximately transverse to the incident wind, to a minimum drag position (glide position). The wings of each pair of pivot shafts open into the drive position at the same time and rotational angle of the turbine. A backstop at the site of each drive position transfers force from each wing to the central drive shaft.