Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 and MD-11F series airplanes. This proposal would require replacement of the existing terminal strips and supports above the main cabin area; and installation of spacers between terminal strips and mounting brackets in the avionics compartment; as applicable. This proposal is prompted by a report indicating that, during flight, an incident of electrical arcing occurred at a terminal strip located overhead in the main cabin. 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.