Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for certain Model 777-200, -300, and -300ER series airplanes. This AD requires installing Teflon sleeving under the clamps of certain wire bundles routed along the fuel tank boundary structure, and cap sealing certain penetrating fasteners of the main and center fuel tanks. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent electrical arcing on the fuel tank boundary structure or inside the fuel tanks, which could result in a fire or explosion.