Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 and -11F airplanes. This proposal would require an inspection to detect damage of the wiring/bundles routed to the wire support bar of the circuit breaker panel and to the circuit breakers, and an inspection of the wiring/bundles for correct routing. This proposal also would require installation of protective sleeving, spacers, and sta-straps; and corrective/follow-on actions, if necessary. This action is necessary to prevent chafing and consequent arcing or loss of electrical power to associated avionics buses in the upper avionics circuit breaker panel of the main observer's station, which could result in smoke and/or fire in the cockpit. This action is intended to address the identified unsafe condition.