Summary
We propose to adopt a new airworthiness directive (AD) for certain McDonnell Douglas Model MD-11 and MD-11F airplanes. This proposed AD would require a one-time inspection to determine if wires touch the upper surface of the center upper auxiliary fuel tank and marking the location, if necessary; a one-time inspection of all wire bundles above the center upper auxiliary fuel tank for splices and damage; a one-time inspection for damage to the fuel vapor barrier seal and upper surface of the center upper auxiliary fuel tank; and corrective actions, if necessary. This proposed AD would also require installation of nonmetallic barrier/shield sleeving, new clamps, new attaching hardware, and a new extruded channel. This proposed AD results from fuel system reviews conducted by the manufacturer. We are proposing this AD to reduce the potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in fuel tank explosions and consequentloss of the airplane.