Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Airbus Industrie Model A300, A300-600, and A310 series airplanes, that currently requires inspections to detect cracks in the lower spar axis of the pylons between ribs 6 and 7, and repair, if necessary. For certain Model A310 series airplanes, this action would reduce the currently required inspection thresholds and intervals, and would remove an option for a terminating modification. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent such fatigue cracking, which could result in reduced structural integrity of the engine pylon's lower spar, and possible separation of the engine from the airplane.