Airworthiness Directives; McDonnell Douglas Model DC-8-11, DC-8-12, DC-8-21, DC-8-31, DC-8-32, DC-8-33, DC-8-41, DC-8-42, and DC-8-43 Airplanes; Model DC-8-50 Series Airplanes; Model DC-8F-54 and DC-8F-55 Airplanes; Model DC-8-60 Series Airplanes; Model DC-8-60F Series Airplanes; Model DC-8-70 Series Airplanes; and Model DC-8-70F Series Airplanes

We are adopting a new airworthiness directive (AD) for all McDonnell Douglas airplanes identified above. This AD requires repetitive inspections of the lower skin and stringers at stations Xw=408 and Xw=-408, and corrective actions if necessary. This AD results from reports of cracks in the skins and stringers at the end fasteners common to the stringer end fittings at stations Xw= 408 and Xw=-408 wing splice joints. We are issuing this AD to detect and correct fatigue cracking in the skins and stringers at the end fasteners common to the stringer end fittings at certain station and wing splice joints, which could result in wing structure that might not sustain limit load, and consequent loss of structural integrity of the wing.