Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing 777 series airplanes. This proposal would require a one-time inspection to detect cracking of the fastener holes common to the upper wing skins and trailing edge panels of both wings, and corrective actions, if necessary. This proposal also would require coldwork of the fastener holes and installation of new or serviceable fasteners. This proposal is prompted by a report indicating that fatigue cracks have been found in the upper wing skin of both wings. The actions specified by the proposed AD are intended to prevent fatigue cracking of the upper wing skin, which could result in reduced structural integrity of the wing.