Airworthiness Directives; McDonnell Douglas Model MD-10-10F and MD-10-30F Airplanes and Model MD-11 and MD-11F Airplanes

The FAA is superseding an existing airworthiness directive (AD), which applies to certain McDonnell Douglas Model MD-11 series airplanes. That AD currently requires a revision of the airplane flight manual (AFM) to alert the flightcrew that both flight management computers (FMCs) must be installed and operational. That AD also requires an inspection to determine the serial number of the FMCs; and follow- on corrective actions, if necessary, which terminate the AFM revision. That AD also requires an inspection to verify if a certain modification is on the identification plates of the FMCs; and applicable follow-on and corrective actions. This new AD requires installation of upgraded FMC software, which would terminate the existing AD. This new AD also adds airplanes to the applicability, including adding Model MD-10-10F and MD-10-30F airplanes. This AD results from a report that the FMC does not acknowledge the pre-set glareshield control panel (GCP) altitude when profile (PROF) mode is engaged in descent mode. We are issuing this AD to prevent the un-commanded descent of an airplane below the selected level-off altitude, which could result in an unacceptable reduction in the separation between the airplane and nearby air traffic or terrain.