Action
Final rule.
Summary
We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes, Model 757 airplanes, Model 767 airplanes, and Model 777 airplanes. This AD results from fuel system reviews conducted by the manufacturer. This AD requires an inspection to determine if certain motor-operated valve (MOV) actuators for the fuel valves are installed, and replacement of any affected actuators. Previous ADs addressed this Special Federal Aviation Regulation No. 88 (SFAR 88) issue for the majority of the airplanes delivered with these actuators. Since those ADs did not cover all of the airplanes, and for some airplanes delivered with improved actuators, there was no restriction on installation of replacement actuators with the unsafe condition, this additional rulemaking action is required. As with the related ADs, we are issuing this AD to prevent electrical energy from lightning, hot shorts, or fault current from entering the fuel tank through the fuel valve actuator shaft, which could result in fuel tank explosions and consequent loss of the airplane.