AD FAA-2017-0330

We propose to adopt a new airworthiness directive (AD) for certain The Boeing Company Model 737-300, -400, and -500 series airplanes. This proposed AD would require repetitive inspections for cracking in the skin lap splice at the lower fastener row, and repair if necessary. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the lower skin at the skin lap splice lower fastener row is subject to widespread fatigue damage (WFD). We are proposing this AD to address the unsafe condition on these products.