AD 2004-13-06 required repetitive detailed inspections to detect cracks in the keel beam side panels, and repair if necessary. This new AD requires repetitive eddy current inspections for cracking in the keel beam side panels, and corrective actions if necessary.
This AD was prompted by reports of cracks on the side panels of the keel beams. We are issuing this AD to detect and correct fatigue cracks on the side panels of the keel beams, which could result in reduced structural integrity of the airplane.
This AD becomes effective September 24, 2013.