Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain McDonnell Douglas Model 717-200 airplanes. This proposed AD would require replacing the lightning critical clamp bases of the fuel tank vent system with improved clamp bases; and checking the electrical bond of the modified self-bonding mounting clamps. This proposed AD results from an investigation that revealed the aluminum foil strip on the nylon base of the ground clamps can fracture or separate from the base. We are proposing this AD to ensure that the fuel pipes are properly bonded to the airplane structure. Improper bonding could prevent electrical energy from a lightning strike from dissipating to the airplane structure, which could result in a fuel tank explosion.