Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This proposal would require modification of the nacelle strut and wing structure, inspections and checks to detect discrepancies, and correction of discrepancies. This proposal is prompted by the development of a modification of the strut and wing structure that improves the fail-safe capability and durability of the strut-to-wing attachments, and reduces reliance on inspections of those attachments. The actions specified by the proposed AD are intended to prevent failure of the strut and subsequent loss of the engine.