Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes. This proposed AD would require replacing the clamp bases for the fuel vent pipe with improved clamp bases. This proposed AD results from reports that the foil wrapping on existing plastic clamp bases has migrated out of position, which compromises the bonding of the fuel vent lines to the airplane structure. We are proposing this AD to ensure that the fuel vent lines are properly bonded to the airplane structure. Improper bonding could prevent electrical energy from a lightning strike from dissipating to the airplane structure, and create an ignition source, which could result in a fuel tank explosion.