Summary
This document proposes the supersedure of two existing airworthiness directives (AD), applicable to all Boeing Model 747 series airplanes, which currently require that the FAA-approved maintenance inspection program be revised to include inspections that will give no less than the required damage tolerance rating for each structural significant item, and repair of cracked structure. Those ADs were prompted by a structural re-evaluation that identified additional structural elements where, if damage were to occur, supplemental inspections may be required for timely detection of fatigue cracking. This action would require additional and expanded inspections, and repair of cracked structure. This action also would expand the applicability of the existing ADs to include additional airplanes. The actions specified by the proposed AD are intended to ensure the continued structural integrity of the entire fleet of Model 747 series airplanes.