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/B727/200 Forward Cargo Door Cutout Frames 1/2006 Applicability: Model 727, 727C, 727-100, and 727-100C series aircraft, line numbers 1 through 694. Requirement: Action in accordance with the technical requirements of FAA AD 2005-20-33 Amdt 39-14330. Note: Boeing Alert Service Bulletin 727-53A0229 original issue, or later FAA approved revision, refers. Compliance: As specified in the Requirement document, with a revised effective date of 19 January 2005. This Airworthiness Directive becomes effective on 19 January 2006. Background: The manufacturer received 42 reports of cracked frames by 20 operators on 29 aircraft. Of the 42 cracks found, 20 were located on the forward frame and 22 on the aft frame of the forward cargo door cutout. Undetected fatigue cracking on the frames of the forward cargo door cutout could result in loss of the door and rapid decompression of the aircraft. David Villiers Delegate of the Civil Aviation Safety Authority 28 November 2005