Action
Final rule.
Summary
We are superseding Airworthiness Directive (AD) 2004-13-02, which applied to certain The Boeing Company Model 747-100, -200B, and - 200F series airplanes. AD 2004-13-02 required repetitive inspections to find discrepancies in the upper and lower skins of the fuselage lap joints, and repair if necessary. This new AD adds post-repair inspections for cracking and corrosion, and repair if necessary; structural modification at the lap joints; and post-modification inspections for cracking and corrosion, and repair if necessary. This AD was prompted by an evaluation by the design approval holder (DAH) that indicates the longitudinal lap joints are subject to widespread fatigue damage (WFD). The actions mandated by this AD are necessary to reach the limit of validity (LOV). We are issuing this AD to detect and correct fatigue cracking in the upper and lower skins of the fuselage lap joints, which could result in sudden fracture and failure of a lap joint and rapid in-flight decompression of the airplane fuselage.