AD/B747/348 Outboard Strut Spring Beam Midpivot Bolt and Midpivot Bolt Access Door (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/B747/348 Outboard Strut Spring Beam Midpivot
Bolt and Midpivot Bolt Access Door 8/2006

Applicability:	Model 747-100B, -200B, -200F, -300, -400, -400F, and 747SP series aircraft; as identified in Boeing Alert Service Bulletin 747-54A2225 original issue, or later FAA approved revision.
Requirement:	Action in accordance with the technical requirements of FAA AD 2006-12-03 Amdt 39-14627.
Compliance:	As specified in the Requirement document, with a revised effective date of 3 August 2006.
This Airworthiness Directive becomes effective on 3 August 2006.
Background:	The FAA received reports indicating that the midpivot bolt and midpivot bolt access door of the spring beam of the inboard side of the outboard struts were installed in the incorrect position.  If not installed in the correct position, a midpivot bolt could be overloaded and crack or fracture, which could result in loss of the spring load path and consequent separation of the associated outboard strut and engine from the aircraft.

David Villiers
Delegate of the Civil Aviation Safety Authority

21 June 2006