Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede Airworthiness Directive (AD) 2004-14- 09, for certain Airbus Model A320-211, -212, and -231 airplanes. AD 2004-14-09 currently requires 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. Since we issued AD 2004-14-09, we have determined 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. This proposed AD would reduce the compliance times for the repetitive inspections, and would require a repair for certain airplanes. We are proposing 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.