Airworthiness Directives; The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

摘要

We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires, depending on airplane configuration, doing certain wiring changes, replacing the fuel pump power control relays for the main, center, and auxiliary tanks, as applicable, with new relays having a ground fault interrupter (GFI) feature, performing certain bonding resistance measurements, and modifying relay module assemblies. This AD also requires revising the maintenance program to incorporate certain Airworthiness Limitations. This AD was prompted by fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent damage to the fuel pumps caused by electrical arcing that could introduce an ignition source in the fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.