Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

Résumé

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This proposed AD would require doing repetitive internal eddy current and detailed inspections to detect cracked stringer tie clips; doing applicable corrective and related investigative actions, if necessary; and measuring the fastener spacing and the edge margin; as applicable. As a temporary alternative to doing the actions described previously, this proposed AD would require repetitive external general visual inspections of the skin and lap joints for cracks and evidence of overload resulting from cracked stringer tie clips, and applicable corrective actions if necessary. This proposed AD results from a report of several cracked stringer tie clips. We are proposing this AD to prevent multiple cracked stringer tie clips and damaged skin and frames, which could lead to the skin and frame structure developing cracks and consequent decompression of the airplane.