Airworthiness Directives; Boeing Model 777 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 777 series airplanes. This action requires repetitive corrosion/resistance inspections to measure the resistance of each wire bundle of the flight control system; and repair of the receptacle bond, repair of the bundle connector backshells, or replacement of the wire bundles with new components, if necessary. This amendment is prompted by reports of corroded connectors and numerous other discrepancies of the wire bundles, such as loose backshells and loose shield retention bands, due to the presence of moisture inside the wire bundles. The actions specified in this AD are intended to detect and correct such corrosion, which could reduce system protection against lightning strikes or high intensity radiated field (HIRF) events, and consequently could adversely affect wire bundles used for the flight control system. This situation could result in loss of function of certain flight control surface actuators in the event of a lightning strike.