Summary
We propose to supersede Airworthiness Directive (AD) 2014-12- 06, for certain Airbus 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); and Airbus Model A310 series airplanes. AD 2014-12-06 currently requires inspections of the external area of the aft cargo door sill beam for cracking, and repair if necessary. Since we issued AD 2014-12-06, we have determined it is necessary to require that high frequency eddy current (HFEC) inspections be performed repetitively. This proposed AD would mandate the previously optional terminating HFEC inspection, and require that it be done repetitively. We are proposing this AD to detect and correct fatigue cracking of the cargo door sill beam, lock fitting, and torsion box plate. Failure of one or more of these components could result in the loss of the door locking function and, subsequently, complete loss of the cargo door in flight with the risk of rapid decompression.