Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 777-200 and -300 series airplanes. This proposed AD would require inspecting for the installation of the tie plate for the wire bundles routed from lower section 41 into the center control stand in the flight deck, and inspecting for any wire chafing or damage and repair if necessary, and installing a tie plate if necessary. This proposed AD is prompted by a report of missing tie plates for the wire bundles. We are proposing this AD to prevent wire chafing, which could result in the loss of flight control, communication, navigation, and engine fire control systems. Loss of these systems could consequently result in a significant reduction of safety margins, an increase in flight crew workload, and in the case where loss of engine fire control is combined with an engine fire, could result in an uncontrollable fire.