Action
Final rule.
Summary
We are superseding an existing airworthiness directive (AD) for the products listed above. That AD currently requires an inspection to determine if a certain fuel pump housing electrical connector is installed. The existing AD also requires a revision to the FAA-approved airplane flight manual (AFM) to advise the flightcrew of the appropriate procedures for disabling certain fuel pump electrical circuits following failure of a fuel pump housing electrical connector if applicable. The existing AD also requires the deactivation of certain fuel tanks or fuel pumps and the installation of placards if applicable. The existing AD allows the optional replacement of the fuel pump housing electrical connectors with new, improved parts, which would terminate the AFM revisions, deactivation of certain fuel tanks and fuel pumps, and placard installation. This new AD instead requires replacing the fuel pump housing electrical connector assembly with a new part and doing repetitive inspections for continuity, resistance, and insulation resistance, and doing corrective actions if necessary. This AD was prompted by reports of failures of a certain fuel pump housing electrical connector. We are issuing this AD to detect and correct insulation resistance degradation and arcing in the potted backside of the electrical connector assembly of the fuel boost/ transfer pump housing, which could compromise its performance and cause an ignition source in the fuel tank, resulting in a fuel tank explosion and consequent loss of the airplane.