Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 Series Airplanes and C-9 Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes and C-9 airplanes. This AD requires an inspection to detect chafing or damage at the conduit and support bracket interface in the forward electrical power center (EPC); and repair or replacement of wires with new wires, if necessary. For certain airplanes, this AD also requires installation of grommets on the conduits of the forward EPC. These actions are necessary to prevent chafing of electrical cables in the forward EPC and a possible short within a conduit, which could result in smoke and fire in the cockpit. These actions are intended to address the identified unsafe condition.