AD FAA-2018-0302

We are superseding Airworthiness Directive (AD) 99-23-16, which applied to certain Airbus Model A330 and A340 series airplanes. AD 99-23-16 required repetitive detailed visual inspections to detect cracking of the vertical flange of the inboard Z-stiffeners of the centerline panel of the fuselage belly fairing; and corrective actions, if necessary. This AD was prompted by a new fatigue and damage tolerance evaluation that concluded that the current inspection thresholds and intervals had to be more restrictive. This AD requires contacting the FAA to obtain instructions for addressing the unsafe condition on these products, and doing the actions specified in those instructions. We are issuing this AD to address the unsafe condition on these products.