Airworthiness Directives; Lockheed Model L-1011-385 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to all Lockheed Model L-1011-385 series airplanes, that currently requires visual inspections to detect cracking of the fittings that attach the aft pressure bulkhead to the fuselage stringers. That AD also currently requires replacement of cracked fittings, and repair of adjacent structure if found to be cracked. This amendment requires new repetitive inspections to detect cracking of the fittings and of the splice tab of the aft pressure bulkhead, and corrective actions, if necessary. This amendment is prompted by the results of the visual inspections performed in accordance with the existing AD, which indicate that the visual inspection is inadequate to detect fatigue cracking. The actions specified in this AD are intended to prevent fatigue cracking of the aft pressure bulkhead, which could lead to failure of the end fittings and splice tabs, and subsequent rapid decompression of the airplane during flight.