Action
Final rule.
Summary
We are superseding Airworthiness Directive (AD) 2011-23-05 for all The Boeing Company Model 737-300, -400, and -500 series airplanes. AD 2011-23-05 required repetitive inspections for cracking of the 1.04- inch nominal diameter wire penetration hole, and applicable related investigative and corrective actions. This new AD adds new inspection areas, a modification that terminates certain inspections, post- modification inspections, and repair if necessary. This AD was prompted by an evaluation by the design approval holder (DAH) that indicates the fuselage frames and frame reinforcements are subject to widespread fatigue damage (WFD). We are issuing this AD to detect and correct fatigue cracking of the fuselage frames and frame reinforcements that could result in reduced structural integrity of the airplane.