AD FAA-2013-0668

We are adopting a new airworthiness directive (AD) for certain Airbus Model A300 B4-600 and A300 B4-600R series airplanes. This AD was prompted by reports of cracks found in certain bottom wing skin stringers during full-scale fatigue testing and in service. This AD requires modifying the profile of stringer run-outs of both wings, including a high frequency eddy current inspection of the fastener holes for defects and, if necessary, repairs. We are issuing this AD to prevent cracking in the bottom wing skin stringers, which could result in reduced structural integrity of the wings.