Airworthiness Directives; Boeing Model 757 Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 757 airplanes. This AD requires inspections of certain wire bundles in the left and right engine-to-wing aft fairings for discrepancies; installation of back-to-back p-clamps between the wire and hydraulic supply tube at the aft end of the right-hand strut only; and associated re-routing of the wire bundles, if necessary. This AD results from a report indicating that a circuit breaker for the fuel shutoff valve tripped due to a wire that chafed against the structure in the flammable leakage zone of the aft fairing, causing a short circuit. We are issuing this AD to prevent chafing between the wire bundle and the structure of the aft fairing, which could result in electrical arcing and subsequent ignition of flammable vapors and possible uncontrollable fire.