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

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD requires repetitive internal eddy current and detailed inspections to detect cracked stringer tie clips; measuring the fastener spacing and the edge margin if applicable, and doing applicable corrective and related investigative actions. As a temporary alternative to doing the actions described previously, this AD requires repetitive external general visual inspections of the skin and lap joints and repetitive external eddy current sliding probe inspections, as applicable, of the lap joints for cracks and evidence of overload resulting from cracked stringer tie clips, and applicable corrective actions if necessary. This AD results from a report of several cracked stringer tie clips. We are issuing this AD to detect and correct multiple adjacent 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.