AD/B747/143 Amdt 1 - Fuselage Section 41 Skin Stringer Joints (Cth)

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/B747/143 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 747 Series Aeroplanes AD/B747/143 Amdt 1 Fuselage Section 41 Skin Stringer Joints 2/2007

Applicability: Model 747-100, -100B, -200B, -200C, -200F, 747SR, and 747SP series aircraft; line numbers 001 through 430. Requirement: Action in accordance with the technical requirements of FAA AD 2006-24-02 Amdt 39-14831. Compliance: As specified in the Requirement document, with a revised effective date of 15 February 2007. This Amendment becomes effective on 15 February 2007. Background: A number of operators reported skin cracks at skin-stringer fastener locations. Some cracks were up to 0.5" long. Skin cracks that reach critical length can cause an in flight de-pressurization.

Amendment 1 is issued in response to a new FAA AD, which requires an additional inspection of areas that may have Alodine-coated rivets installed. The FAA received a report of cracking that was detected in a skin lap joint previously inspected using the eddy current method.

David Villiers Delegate of the Civil Aviation Safety Authority