Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all British Aerospace Model BAC 1- 11 200 and 400 series airplanes. This proposal would require 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 proposal also would require revising the Airplane Flight Manual to provide the flight crew with procedures to address uncontrolled operation of the thrust reverser system. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed 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.