AD/B747/365 Centre and Outer Wing Fuel Tanks (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/B747/365 Centre and Outer Wing Fuel Tanks 12/2007

Applicability:	Model 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F and 747SP series aeroplanes, as identified in Boeing Special Attention Service Bulletin (SB) 747-57-2327, Revision 1, dated 10 July 2006 and Boeing Special Attention SB 747-57-2326, dated 4 January 2007.
Requirement:	1.    Reconfigure the wire bundle clamps and seal the ends of certain fasteners inside the auxiliary fuel tank, main fuel tanks and surge fuel tanks, in accordance with the Accomplishment Instructions of Special Attention SB 747-57-2327, Revision 1.
2.    Seal the ends of certain fasteners inside the main fuel tanks, in accordance with the Accomplishment Instructions of Special Attention SB 747-57-2326.
Later revisions of the above SBs, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2007-20-01, are considered acceptable for compliance with the equivalent Requirements of this Directive.
Note:  FAA AD 2007-20-01 Amdt 39-15211 refers.
Compliance:	For Requirements 1 and 2 - Within 60 months after the effective date of this Directive.
This Airworthiness Directive becomes effective on 22 November 2007.
Background:	This Directive requires reconfiguring the clamps of certain wire bundles and applying insulating sealant to certain fasteners inside the fuel tanks.  The Directive results from fuel system reviews conducted by the manufacturer and is issued to prevent arcing inside the fuel tanks in the event of a lightning strike or high-powered short circuit, which could result in a fuel tank explosion or fire.

David Punshon
Delegate of the Civil Aviation Safety Authority

2 October 2007