AD FAA-2017-0520

We are adopting a new airworthiness directive (AD) for certain Airbus Model A300 series airplanes; and Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300 C4-605R Variant F airplanes (collectively called Model A300-600 series airplanes). This AD was prompted by reports of cracks initiating at the upper radius of a certain frame and a determination that the current inspection procedure is not reliable in detecting certain cracking of the forward fitting of the frame. This AD requires repetitive inspections to detect cracking of the upper radius of the forward fitting of a certain frame, and related investigative actions and corrective actions if necessary. We are issuing this AD to address the unsafe condition on these products.