Airworthiness Directives; Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-100, -200, -300, -400, and -500 series airplanes, that requires repetitive inspections to detect cracking of various areas of the forward pressure bulkhead, and repair, if necessary. This amendment also provides for certain optional preventive modifications, which, if accomplished, would terminate the repetitive inspections for the affected areas. This amendment is prompted by reports indicating that numerous fatigue cracks were found on critical areas of the forward pressure bulkhead. The actions specified by this AD are intended to prevent such fatigue cracking, which could result in rapid decompression of the airplane fuselage.