Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-100, 737-200, 737-200C, 737-300, 737-400, and 737-500 series airplanes. This AD was prompted by reports of cracking in the lower corners of the forward entry doorway and the upper corners of the airstairs cutout. This AD requires inspections for cracking of the forward entry doorway and airstairs cutout, and corrective actions if necessary. This AD also provides terminating action for the repetitive inspections. We are issuing this AD to detect and correct cracks in the lower corners of the forward entry door cutout and the upper corners of the airstairs cutout, which could progress and result in an inability to maintain cabin pressurization.