Airworthiness Directives; Boeing Model 757 Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 757 airplanes. This AD requires, for certain airplanes, reworking the spar bonding path and reapplying sealant; and, for certain other airplanes, testing the electrical bond between the engine fuel feed hose and the wing front spar and, if applicable, reworking the spar bonding path and reapplying sealant. This AD also requires, for all airplanes, an inspection to ensure the electrical bonding jumper is installed between the engine fuel feed tube and the adjacent wing station. This AD also requires operators that may have installed an incorrect O-ring to install the correct part and do a re- test. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent arcing or sparking at the interface between the bulkhead fittings of the engine fuel feed tube and the front spar during a lightning strike, which could provide a possible ignition source for the fuel vapor inside the fuel tank and result in a fuel tank explosion.