Abstract: A slat system in which the slats are supported on tracks and the slats are actuated by a simple bell crank linkage oriented so that its plane of motion is parallel to the wing chord reference plane. The mechanism retracts to a collapsed over-center position and extends to an over-center position so as to lock the slat into the retract or extend positions. Each slat segment is driven by two identical mechanisms tied together by a synchronization link which provides redundancy. Either actuator can drive the surface alone, as the second actuator is driven through the synchronization lever, in case of power loss to the second actuator.