AD FAA-2013-0461

We are superseding Airworthiness Directive (AD) 2009-06-02, which applied to certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747SR, and 747SP series airplanes. AD 2009-06-02 required repetitive inspections for skin cracks at the shear tie end fastener locations of the fuselage frames, and repair of cracks if necessary. This new AD also requires repetitive inspections for skin cracks next to the shear tie on airplanes with certain existing repair doublers, and corrective actions if necessary. This AD also revises the applicability to include additional airplanes. This AD was prompted by additional cracking found on an airplane not affected by AD 2009-06-02. We are issuing this AD to detect and correct fatigue cracks in the fuselage skin that can propagate and grow, and result in reduced structural integrity and sudden decompression of the airplane in flight.