AD FAA-2012-0678

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-400 and -400F series airplanes. This AD was prompted by multiple reports of integrated display unit (IDU) malfunctions and mode control panel (MCP) malfunctions. This AD requires installing new software, replacing the duct assembly with a new duct assembly, making wiring changes, and routing certain wire bundles. We are issuing this AD to prevent IDU malfunctions, which could affect the ability of the flightcrew to read primary displays for airplane attitude, altitude, or airspeed, and consequently reduce the ability of the flightcrew to maintain control of the airplane.