Summary
We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model DC-8-55, 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. This proposed AD was prompted by multiple reports of cracking of the upper aft skin panel of the fuselage. An evaluation by the design approval holder (DAH) indicates that the upper aft skin panel of the fuselage is subject to widespread fatigue damage (WFD). This proposed AD would require removing any previously installed local repairs; installing a full-length improvement modification with finger doublers or a full-length repair with finger doublers; and repetitive inspections for cracking of the doublers, and repair if necessary. We are proposing this AD to detect and correct fatigue cracking of the upper aft skin panel of the fuselage, which could result in loss of structural integrity and consequent rapid decompression of the airplane.