AD FAA-2013-0539

We are superseding airworthiness directive (AD) 2000-12-11, for certain Model A300 B4-600 and Model A300 B4-600R series airplanes. AD 2000-12-11 required repetitive inspections to detect cracks in the bolt holes inboard and outboard of rib 9 on the bottom booms of the front and rear wing spars, and repair if necessary. This new AD reduces the initial inspection compliance time and repetitive inspection interval. This AD was prompted by a fleet survey and an updated fatigue and damage tolerance analysis indicating a high risk for fatigue cracking on the front and rear spar bottom booms. We are issuing this AD to detect and correct fatigue cracks in the bolt holes of the wing spars, which could result in reduced structural integrity of a wing spar.