Airworthiness Directives; Airbus Model A300 B4-600, B4-600R, and F4-600R Series Airplanes, and Model A300 C4-605R Variant F Airplanes (Collectively Called A300-600 Series Airplanes)

The FAA is superseding an existing airworthiness directive (AD), which applies to certain Airbus Model A300-600 series airplanes. That AD currently requires repetitive eddy current inspections to detect cracks of the outer skin of the fuselage at certain frames, and repair or reinforcement of the structure at the frames, if necessary. That AD also requires eventual reinforcement of the structure at certain frames, which, when accomplished, terminates the repetitive inspections. This new AD requires, for airplanes that were previously reinforced but not repaired in accordance with the existing AD, a one- time inspection for cracking of the fuselage outer skin at frames 28A and 30A above stringer 30, and repair if necessary. This AD results from a report that the previously required actions were not sufficient to correct cracking before the structural reinforcement was installed. We are issuing this AD to prevent such fatigue cracking, which could result in reduced structural integrity, and consequent rapid decompression of the airplane.