Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 and MD-11F airplanes, that currently requires replacing terminal strips and supports above the main cabin area and avionics compartment with new strips and supports, as applicable. That AD also requires performing an inspection to detect arcing damage of the surrounding structure of the terminal strips and electrical cables in the avionics compartment, and repairing or replacing any damaged component with a new component. This action would expand the applicability of the existing AD to include additional airplanes. For certain airplanes, this action also would require replacement of the terminal board for the applicable item numbers in the aft passenger compartment. The actions specified by the proposed AD are intended to prevent electrical arcing caused by power feeder cable terminal lugs grounding against terminal strip support brackets, which could result in smoke and fire in the main cabin or avionics compartment. This action is intended to address the identified unsafe condition.