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 747 Series Aeroplanes AD/B747/352 Overlapped Skin Panels in the 13/2006 Fuselage Skin Lap Joints Applicability: Model 747-100, -100B, -100B SUD, -200B, -200C, -200F, -300, -400, -400D, -400F, 747SR, and 747SP aircraft; as identified in Boeing Alert Service Bulletin 747-53A2501 original issue, dated 24 March 2005, or later FAA approved revision. Requirement: Action in accordance with the technical requirements of FAA AD 2006-22-09 Amdt 39-14806. Compliance: As specified in the Requirement document, with a revised effective date of 21 December 2006. This Airworthiness Directive becomes effective on 21 December 2006. Background: The FAA received a report indicating that an operator found multiple small cracks in the overlapped skin panels in the fuselage skin lap joints. Such cracking, unless detected and corrected, could join together and result in reduced structural capability in the skin and consequent rapid decompression of the aircraft. David Villiers Delegate of the Civil Aviation Safety Authority 8 November 2006