Airworthiness Directives; Boeing Model 737-200, -200C, -300, and -400 Series Airplanes

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-200, -200C, -300, and -400 series airplanes. This action requires repetitive inspections to detect cracking of the corners of the door frame and the cross beams of the aft cargo door, and corrective actions, if necessary. This action also provides an optional terminating action for the repetitive inspection requirement of this AD. This amendment is prompted by reports indicating that fatigue cracks have been detected in the corners of the door frame and the cross beams of the aft cargo door on several in- service airplanes, and by another report indicating that rapid depressurization occurred during flight on one of those airplanes. The actions specified in this AD are intended to prevent fatigue cracking of the corners of the door frame and the cross beams of the aft cargo door, which could result in rapid depressurization of the airplane.