Summary
The FAA proposes to adopt a new airworthiness directive (AD) for certain McDonnell Douglas Model DC-9-10, DC-9-20, DC-9-30, DC-9-40, and DC-9-50 series airplanes. This proposed AD would require repetitive inspections for stress corrosion cracks of the main fuselage frame, and corrective actions if necessary. This proposed AD also would provide an optional terminating action for the repetitive inspections. This proposed AD results from several reports of cracking of the main fuselage frame. We are proposing this AD to detect and correct stress corrosion cracking of the main fuselage frame, which could result in extensive damage to adjacent structure, and reduced structural integrity of the airplane.