Summary
We propose to adopt 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 proposed AD was prompted by the determination that certain existing inspection thresholds and intervals must be reduced. This proposed AD would require repetitive detailed inspections for corrosion, and related investigative and corrective actions if necessary. We are proposing this AD to detect and correct corrosion and cracking on the lower wing root joint, which could reduce the structural integrity of the airframe.