Airworthiness Directives; McDonnell Douglas Model DC-9-10, DC-9-20, DC-9-30, DC-9-40, and DC-9-50 Series Airplanes; Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) Airplanes; Model MD-88 Airplanes; Model MD-90-30 Airplanes; and Model 717-200 Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain McDonnell Douglas transport category airplanes. This AD requires an inspection to determine the part number of the upper and lower stop pad support fittings of all the lower cargo doors, repetitive inspections of all early configuration stop pad support fittings, and corrective action if necessary. This AD also provides an optional terminating action for the repetitive inspections. This AD results from a report of cracks found in the area of the upper and lower stop pad support fittings of the cargo door pan on numerous airplanes. We are issuing this AD to prevent cracks in the cargo door pan, which could result in the inability to fully pressurize an airplane, possible pressure loss, or possible rapid decompression of the airplane.