Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all of the McDonnell Douglas Corporation airplanes identified above. The existing AD currently requires revising the maintenance program to incorporate new airworthiness limitations for fuel tank systems to satisfy Special Federal Aviation Regulation No. 88 requirements. This proposed AD would add requirements to revise the maintenance program to incorporate specific Critical Design Configuration Control Limitations (CDCCL) information and install fuel tank float switch in-line fuses. This proposed AD would also add two Airworthiness Limitations inspections (ALIs). This proposed AD results from a design review of the fuel tank systems. We are proposing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.