Airworthiness Directives; Airbus Model A318, A319, A320, and A321 Airplanes

The FAA is superseding an existing airworthiness directive (AD), which applies to certain Airbus Model A318, A319, A320, and A321 airplanes. That AD currently requires inspecting to determine the part number and serial number of the fuel tank boost pumps and, for airplanes with affected pumps, revising the airplane flight manual (AFM) and the FAA-approved maintenance program. The existing AD also provides for optional terminating action for compliance with the revisions to the AFM and the maintenance program. This new AD requires modifying or replacing the fuel tank boost pumps, which would terminate the AFM limitations and the maintenance program revisions. This AD results from a report that a fuel tank boost pump failed in service, due to a detached screw of the boost pump housing that created a short circuit between the stator and rotor of the boost pump motor and tripped a circuit breaker. We are issuing this AD to prevent electrical arcing in the fuel tank boost pump motor, which, in the presence of a combustible air-fuel mixture in the pump, could result in an explosion and loss of the airplane.