AD FAA-2012-1316

We are revising an existing airworthiness directive (AD) for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That AD currently requires repetitive inspections to detect cracking in the web of the aft pressure bulkhead at body station 1016 at the aft fastener row attachment to the "Y" chord, various inspections for discrepancies at the aft pressure bulkhead, and related investigative and corrective actions if necessary. This new AD requires clarifying certain actions specified in the existing AD. This AD was prompted by several reports of fatigue cracks in the aft pressure bulkhead. We are issuing this AD to detect and correct such fatigue cracking, which could result in rapid decompression of the fuselage.