Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series Airplanes Equipped With Heath Tecna Aerospace Extended Spacial Concept Interior III Installed in Accordance With Supplemental Type Certificate SA4744NM

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas DC-9-80 series airplanes, that requires an inspection to detect discrepancies of electrical plugs and receptacles of the sidewall lighting system in the passenger cabin, and to verify that the ends of all pins and sockets are even and that they are seated and locked into place. This amendment also requires replacement of any discrepant part with a new part, and modification of the electrical wiring and connectors of the sidewall lighting system in the passenger cabin. This amendment is prompted by reports of failures of the electrical connectors in the sidewall fluorescent lighting, which resulted in smoke or lighting interruption in the passenger cabin. The actions specified by this AD are intended to prevent failures of the electrical connectors, which could result in poor socket/pin contact, excessive heat, electrical arcing, and consequently, connector burnthrough and smoke in the passenger cabin.