AIRWORTHINESS DIRECTIVE
On the effective date specified below, and for the reasons set out in the background section, the CASA delegate whose signature appears below revokes Airworthiness Directive (AD) AD/B737/270 and issues the following AD under subregulation 39.001(1) of CASR 1998.  The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
Boeing 737 Series Aeroplanes
AD/B737/270 Amdt 1
Aft Pressure Bulkhead Web - 2
12/2012
 
Applicability:
All Model 737-600, -700, -700C, -800, and -900 series aircraft.

Requirement:
Action in accordance with the technical requirements of FAA AD 2005-21-06 Amdt 39-14344.
Note:  Boeing Service Bulletin 737-53A1248 original issue, or later FAA approved revision refers.
The inspections required by paragraph (f) of referenced FAA AD 2005-21-06 are not required for production line number 1756 and subsequent line numbers.  Refer FAA AMOC letter 120S-05-566 dated Nov 18, 2005.

Compliance:
As specified in the requirement document.

 
This Amendment becomes effective on 8 June 2012.

Background:
The FAA received reports of fatigue cracks in the aft pressure bulkhead web.  The actions specified by this Directive are intended to detect and correct such fatigue cracks, which could result in a rapid decompression of the aircraft.

 
Boeing production changes have resulted in a thicker gauge web material for the rear pressure bulkhead web, with the result that the inspections required by paragraph (f) of FAA AD 2005-21-06 are no longer required for production line number 1756 and subsequent line numbers.

 
The original issue of this Airworthiness Directive became effective on
19 January 2006.

Mike Higgins
Delegate of the Civil Aviation Safety Authority
4 June 2012