AD FAA-2015-5809

We are superseding Airworthiness Directive (AD) 2006-19-12 for certain The Boeing Company Model 777-200 and -300 series airplanes. AD 2006-19-12 required inspecting the lower web of the aft fairing of the engine struts for any discoloration, and doing related investigative and corrective actions if necessary; inspecting the heat shield castings for any damage and doing corrective action if necessary; installing gap cover strips; and replacing insulation blankets with new insulation blankets. This new AD retains those requirements and also requires, depending on airplane configuration, one-time or repetitive detailed inspections for cracking and deformation, as applicable, of the aft fairing lower structure, and one-time or repetitive conductivity inspections of the aft fairing lower structure, and related investigative and corrective actions if necessary. This new AD also adds airplanes to the applicability. This AD was prompted by a report that an aft fairing lower spar web exceeded the allowable conductivity limits. We are issuing this AD to address the unsafe condition on these products.