Airworthiness Directives; McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), and MD-88 Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas airplane models, that requires a one-time inspection for chafing or signs of arcing of the wire bundle for the auxiliary hydraulic pump, and other specified and corrective actions, as applicable. This AD also requires that, for certain airplanes, installation of additional protective sleeving on the upper portion of the auxiliary hydraulic pump wire assembly. This AD results from reports of shorted wires and evidence of arcing on the power cables of the auxiliary hydraulic pump, as well a fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent shorted wires or arcing at the auxiliary hydraulic pump, which could result in loss of auxiliary hydraulic power, or a fire in the wheel well of the airplane. The actions specified by this AD are also intended to reduce the potential of an ignition source adjacent to the fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.