Airworthiness Directives; Boeing Model 737-600, -700, -700C, -800, and -900 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes, that requires replacement of the existing fueling float switch and conduit assemblies in the main and center fuel tanks with new, improved assemblies. The actions specified by this AD are intended to prevent fluid contamination inside the fueling float switch or chafing of the wiring to the in-tank conduit, which could generate an ignition source and consequent fire and explosion in the fuel tank. This action is intended to address the identified unsafe condition.