Action
Notice of proposed rulemaking (NPRM).
Summary
We propose to supersede airworthiness directive (AD) 2002-10- 11, which applies to certain the Boeing Company Model 737-100, -200, - 200C, -300, -400, and -500 series airplanes. AD 2002-10-11 currently requires repetitive inspections for cracking and corrosion of the aft pressure bulkhead, and corrective actions if necessary; and, for certain airplanes, enlargement of frame chord drain holes, and repetitive inspections of the frame chord drain path for debris, and corrective actions if necessary. Since we issued AD 2002-10-11, we have received three reports of severe corrosion in the area affected by that AD. This proposed AD would, for certain airplanes, reduce the repetitive inspection interval, and add repetitive inspections of the frame chord drain path for obstructions and debris, and corrective actions if necessary. This proposed AD would also limit corrosion and cracking repairs of the aft pressure bulkhead accomplished after the effective date of this AD to those approved by the FAA in a manner described therein. In reviewing AD 2002-10-11, we noted that the drain path inspection was not required for certain airplanes, and could be eliminated for all airplanes if operators accomplished certain actions required by AD 2002-10-11. This proposed AD would add a drain path inspection for all airplanes. We are proposing this AD to detect and correct corrosion or cracking of the aft pressure bulkhead, which could result in loss of the aft pressure bulkhead web and stiffeners, and consequent rapid decompression of the airplane.