Airworthiness Directives; McDonnell Douglas Model MD-11 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain MD-11 series airplanes, that requires a one-time visual inspection to detect discrepancies of the seat tracks and adjacent structure underneath lavatories, and repair, if necessary. This amendment also requires installation of a non-metallic barrier on the bottom of each lavatory foot fitting, and replacement of existing seat track fittings with new seat track fittings. This amendment is prompted by reports of galvanic corrosion found on the seat tracks at attachment points under certain lavatories. The actions specified by this AD are intended to prevent corrosion of seat tracks and adjacent structure. Corrosion of the seat tracks and adjacent structure could result in shifting of lavatories, which could lead to injury of passengers and crew, as well as damage to aircraft structure and systems.