Airworthiness Directives; Boeing Model 747-100, -200, -300, -400, 747SP, and 747SR Series Airplanes

摘要

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747-100, -200, -300, -400, 747SP, and 747SR series airplanes, that requires a one-time visual inspection to determine the part number of the fuel shutoff valve installed in the outboard engines. The AD also requires replacement of certain valves with new valves, or modification of the spar valve body assembly, and various follow-on actions. This amendment is prompted by reports indicating that, due to high fuel pressure, certain fuel system components of the outboard engines have failed on in-service airplanes. The actions specified by this AD are intended to prevent such high fuel pressure, which could result in failure of the fuel system components; this situation could result in fuel leakage and, consequently, lead to an engine fire.