Airworthiness Directives; Boeing Model 757 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes, that currently requires an inspection of the engine fuel shutoff valves (spar valves) to detect leakage of fuel and to ensure that no leakage occurs when the valves are commanded to close. That amendment also requires an alignment procedure of the engine fuel shutoff valves, if necessary. This amendment expands the applicability of the existing AD. This amendment is prompted by additional reports that certain crossfeed valve assemblies and engine shutoff valve assemblies were improperly installed during manufacturing of the airplane. The actions specified in this AD are intended to prevent uncommanded fuel flow from the fuel tanks to the engine nacelle, which could result in reduced airplane fire protection in the event of a leak in the engine fuel line or a fire in the engine nacelle.