Summary
We propose to adopt 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 proposed 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 proposed AD would require inspections for cracking of the forward entry doorway and airstairs cutout, and corrective actions if necessary. This proposed AD also provides terminating action for the repetitive inspections. We are proposing 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.