AD/B747/362 Aft Tension Tie Channels (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/B747/362 Aft Tension Tie Channels 10/2007

Applicability:	Model 747-200B, -300, and -400 series aircraft; as identified in Boeing Alert Service Bulletin 747-53A2610 original issue, or later FAA approved revision.
Requirement:	Action in accordance with the technical requirements of FAA AD 2007-16-19 Amdt 39-15158.
Compliance:	As specified in the Requirement document, with a revised effective date of 27 September 2007.
This Airworthiness Directive becomes effective on 27 September 2007.
Background:	The FAA received a report of cracks found in the aft tension tie channels at four station locations, on a Model 747-200B series aircraft that had been modified to a special freighter.  Undetected cracking of the aft tension tie channels, and failure of more than one tension tie could result in rapid decompression of the aircraft.

Charles Lenarcic
Delegate of the Civil Aviation Safety Authority

17 August 2007