Summary
This document revises an earlier proposed airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 and -11F airplanes, that would have required an inspection to detect chafed wires in the avionics equipment compartment, and repair, if necessary. That proposed AD also would have required replacement of the existing cover of the avionics cooling fan with a new cover, and [[Page 55363]] installation of a new placard on the cover. This new action revises the proposed rule by revising which previously accomplished actions are acceptable for compliance with certain requirements of this proposed AD; and clarifying the applicability, a part number, and the inspection definition. This action is necessary to ensure that the cover of the avionics cooling fans is removed only for fan maintenance, and to prevent smoke and/or fire in the avionics equipment compartment due to chafing and arcing as a result of maintenance personnel lying against the removed cover and/or insulation blankets that cover wire harnesses. This action is intended to address the identified unsafe condition.