Airworthiness Directives; British Aerospace Model BAC 1-11 200 and 400 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to to all British Aerospace Model BAC 1-11 200 and 400 series airplanes, that requires replacing the thrust reverser control unit selector valve with a new or modified valve and inspecting for proper rigging of the thrust reverser cable drums and thrust reverser control unit selector valve detent, and corrective actions, if necessary. This amendment also requires revising the Airplane Flight Manual to provide the flight crew with procedures to address uncontrolled operation of the thrust reverser system. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to provide the flight crew with procedures in the event of uncommanded deployment of the thrust reverser, and to prevent uncommanded deployment of the thrust reverser in flight or on the ground, which could result in reduced controllability of the airplane.