Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that lap splices for certain stringers are subject to widespread fatigue damage (WFD). This AD requires repetitive inspections for cracking in the lower fastener row of the lap splices of certain stringers, and repair if necessary. We are issuing this AD to address the unsafe condition on these products.