AIRWORTHINESS DIRECTIVE For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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 727 Series Aeroplanes AD/B727/207 Aft Pressure Bulkhead Web 13/2007 DM Applicability: All Boeing Model 727, 727C, 727-100, 727-100C, 727-200, and 727-200F series aircraft. Requirement: Action in accordance with the technical requirements of FAA AD 2007-21-04. Note: Boeing Special Attention Service Bulletin 727-53-0230, dated 8 January 2007, refers. Compliance: In accordance with Requirement document, with a revised effective date of 16 November 2007. This Airworthiness Directive becomes effective on 16 November 2007. Background: This Airworthiness Directive results from reports of cracking in the aft pressure bulkhead web. Cracking of this type may result in rapid decompression of the aircraft. This Airworthiness Directive requires an initial inspection for cracks in the aft pressure bulkhead web, as well as rectification action if cracks are found. David Villiers Delegate of the Civil Aviation Safety Authority 15 October 2007