Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for all McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes. This AD requires replacing the clamp bases for the fuel vent pipe with improved clamp bases. This 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 issuing 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.