Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to all Airbus Industrie Model A300-600 series airplanes, that currently requires inspections to detect cracks in the center spar sealing angles adjacent to the pylon rear attachment and in the adjacent butt strap and skin panel, and corrections of discrepancies. That AD was prompted by reports of cracking in the vertical web of the center spar sealing angles of the wing. This action would require that the initial inspections be accomplished at reduced thresholds. This action also would limit the applicability of the existing AD. The actions specified by the proposed AD are intended to prevent crack formation in the sealing angles; such cracks could rupture and lead to subsequent crack formation in the bottom skin of the wing, and resultant reduced structural integrity of the center spar section of the wing.