Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-200, -300, -400, and -500 series airplanes. This AD was prompted by reports of cracks in the frame web common to the stringer ties adjacent to the air-conditioning support brackets. This AD requires an inspection of the frame for any air- conditioning bracket assembly or intercostal, and, depending on the results, repetitive inspections of the frame web for cracking of certain locations, and applicable on-condition actions. We are issuing this AD to address the unsafe condition on these products.