AD/B747/341 Fuselage Lap Joints at sections 41, 42, and 46 (Cth)

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/B747/341 Fuselage Lap Joints at Sections 41, 42, and 46 6/2006

Applicability:	Model 747-200C, -200F, -400, -400D, and -400F series aircraft; as identified in Boeing Alert Service Bulletin 747-53A2499, or later FAA approved revision.
Requirement:	Action in accordance with the technical requirements of FAA AD 2006-05-09 Amdt 39-14506.
Compliance:	As specified in the Requirement document, with a revised effective date of 8 June 2006.
This Airworthiness Directive becomes effective on 8 June 2006.
Background:	This Directive requires repetitive inspections for cracks in the overlapping skin upper fastener row of the lap joints of certain areas of the fuselage skin.  The inspection requirements result from fatigue tests, and an analysis that identified areas of the lap joints where fatigue cracks can occur.

Richard Castles
Delegate of the Civil Aviation Safety Authority

18 April 2006