Airworthiness Directives; the Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for all the Boeing Company Model 767 airplanes. This AD was prompted by a report of a rotary actuator for the trailing edge (TE) flap that had slipped relative to its mating reaction ring, which is attached to the flap support rib. This AD requires repetitive inspections for corrosion of the fixed ring gear and reaction ring splines of the rotary actuator assembly for each support position, and related investigative and corrective actions if necessary. We are issuing this AD to detect and correct flap rotary actuator gear disengagement from its mating reaction ring. This disengagement with flaps extended could cause an uncommanded roll due to flap blowback, overload, or flap departure from the airplane, which could compromise safe flight and landing of the airplane.