Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to certain Airbus Model 330-300 series airplanes. The existing AD currently requires reinforcement of the structure of the center fuselage by installing external stiffeners (butt straps) at frame (FR) 53.3 on the fuselage skin between left-hand (LH) and right-hand (RH) stringer (STR) 13, and related investigative and corrective actions. This proposed AD would require additional reinforcement of the structure of the center fuselage by installing external stiffeners (butt straps) at frame FR53.3 on the fuselage skin between LH and RH STR13, and related investigative and other specified actions. This proposed AD also adds airplanes to the applicability. This proposed AD results from cracking found at the circumferential joint of FR53.3. We are proposing this AD to prevent fatigue cracking of the fuselage, which could result in reduced structural integrity of the fuselage.