Summary
We propose to adopt a new airworthiness directive (AD) for the McDonnell Douglas airplanes listed above. This proposed AD would require modifying the fuel boost pumps for the center wing, and forward or aft auxiliary fuel tanks. This proposed AD results from fuel system reviews conducted by the manufacturer. We are proposing this AD to prevent possible sources of ignition in a fuel tank caused by an electrical fault or uncommanded dry operation of the fuel boost pumps. An ignition source in the fuel tank could result in a fire or an explosion and consequent loss of the airplane.