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

The FAA is adopting 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 AD requires repetitive inspections for stress corrosion cracks of the main fuselage frame, and corrective actions if necessary. This AD also provides an optional terminating action for the repetitive inspections. This AD results from several reports of cracking of the main fuselage frame. We are issuing 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.