Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that currently requires repetitive inspections for cracking in the inboard strut-to-diagonal brace attach fittings and repair or replacement, if necessary. This action would require an additional inspection of those attach fittings, and additional inspections in an area beyond that specified in the existing AD. This action also would provide an optional terminating action for the required inspections, and would expand the applicability of the existing AD to include additional airplanes. This proposal is prompted by reports of cracking and severing of the attach fittings. The actions specified by the proposed AD are intended to prevent failure of the strut and separation of an engine from the airplane due to cracking of the inboard strut-to-diagonal brace attach fittings.