Summary
This document revises an earlier proposed airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 airplanes, that would have required a one-time detailed visual inspection of the wire bundle installation behind the first observer's station to detect damaged or chafed wires; and corrective action, if necessary. That earlier proposed AD also would have required an inspection of the wire bundle installation behind the first observer's station to detect damaged or chafed wires; repair if necessary; installation of a grommet around the lower edge of the feed-through; replacement of the support bracket with a new bracket; and relocation of the support clamp of the wire bundle; as applicable. That proposal was prompted by the FAA's determination that the existing support bracket and the location of the support clamp of the wire bundle may not adequately preclude the wire bundle contained in the feed-through behind the first observer's station from contactingthe bottom portion of the feed-through. This new action revises the proposed rule by specifying new corrective actions. The actions specified by this new proposed AD are intended to prevent such contact, which could cause cable chafing, electrical arcing, smoke, or fire in the cockpit.