Airworthiness Directives; Airbus Airplanes

We are superseding Airworthiness Directive (AD) 2004-14-09 for certain Airbus Model A320-211, -212, and -231 airplanes. AD 2004-14-09 required repetitive inspections for fatigue cracking of the lower surface panel on the wing center box, and repair if necessary; and modification of the lower surface panel on the wing center box, which constitutes terminating action for the repetitive inspections. This new AD retains the requirements of AD 2004-14-09, reduces the compliance times for the repetitive inspections, and requires an additional repair for certain airplanes. This AD was prompted by a determination that, based on the average flight duration, the average weight of fuel at landing is higher than that defined for the analysis of the fatigue-related tasks; and that shot peening might have been improperly done on the chromic acid anodizing (CAA) protection, which would adversely affect fatigue crack protection. We are issuing this AD to detect and correct fatigue cracking of the lower surface panel on the wing center box, which could result in reduced structural integrity of the airplane.