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/B727/198 Lower Lobe Frames of Body Section 43 13/2005 Applicability: All 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 2005-20-13 Amdt 39-14307. Note: Boeing Alert Service Bulletin 727-53A0227 original issue, or later FAA revision, refers. Compliance: As specified in the Requirement document, with a revised effective date of 22 December 2005. This Airworthiness Directive becomes effective on 22 December 2005. Background: The FAA received the results from reports of cracks at open tooling holes in the lower lobe frames of body section 43. The actions required by this Directive are intended to detect and correct cracks in the frames, which could result in cracks in the skin panels and rapid decompression of the aircraft. David Villiers Delegate of the Civil Aviation Safety Authority 8 November 2005