Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all British Aerospace Model BAC 1-11 200 and 400 series airplanes, that currently requires visual inspections to detect cracks in the flight deck canopy area, and repair, if necessary. This action would reduce the inspection threshold and repetitive inspection interval, and would identify specific structural members to be inspected. This action also would require eddy current inspections to detect cracks of the top sill members at station 82.5, and replacement of cracked parts with new parts, or repair of the top sill members. This proposal is prompted by reports of additional cracking found in the structural members in the flight deck canopy area of the affected airplanes. The actions specified by the proposed AD are intended to ensure that cracking in the flight deck canopy area is detected and corrected in a timely manner; such cracking could result in reduced structural integrity of the cockpit frame and the adjacent fuselage structure.