Summary
We propose to supersede Airworthiness Directive (AD) AD 2016- 20-11, 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 2016-20-11 requires repetitive inspections of the external area of the aft cargo door sill beam for cracking, repetitive inspections for fatigue cracking of the cargo door sill beam, lock fitting, and torsion box plate, and repair if necessary. Since we issued AD 2016-20-11, we have determined that reinforcement of the aft cargo door sill beam area is necessary to address the unsafe condition, which constitutes terminating action for the repetitive inspections. This proposed AD would retain the inspections for cracking, and repair if necessary; and require reinforcement of the aft cargo door sill beam area. We are proposing this AD to address the unsafe condition on these products.