Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-600, -700, -700C, -800, and -900 series airplanes. This proposal would require replacement of the existing fueling float switch and conduit assemblies in the main and center fuel tanks with new, improved assemblies. This action is necessary 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.