Airworthiness Directives; Boeing Model 747 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This action requires disconnection of the electrical connector to the scavenge pump of the center wing tank. This AD also requires a one-time inspection to identify the part number of the electrical connector; and replacement of the pump with a new pump, if necessary. This amendment is prompted by findings from a design review and analysis of scavenge pumps installed on certain Boeing Model 747 series airplanes that was undertaken as part of an accident investigation. The actions specified in this AD are intended to prevent potential failures within the electrical motor assembly of the scavenge pump, which could result in leakage of fuel from the electrical connector into the main landing gear wheel well, or electrical arcing within the scavenge pump motor; these conditions could result in a fuel fire in the wheel well.