Summary
We propose to supersede Airworthiness Directive (AD) 98-22-10, which applies to certain The Boeing Company Model 737-100, -200, -200C, and -300 series airplanes. AD 98-22-10 currently requires repetitive inspections for cracking of the aft frame and frame support structure of the forward service doorway, and repair if necessary. AD 98-22-10 also provides for an optional terminating action for the repetitive inspection requirements of that AD. Since we issued AD 98-22-10, we have determined that additional inspections are needed, and that additional airplanes may be subject to the identified unsafe condition. This proposed AD would add inspections and add airplanes to the applicability. For certain airplanes, this proposed AD provides a preventive modification, which would terminate the repetitive inspections. We are proposing this AD to detect and correct fatigue cracking of the aft frame and frame support structure of the forward service doorway around the six doorstop fittings, which could result in door deflection and loss of pressurization.