AD/B747/157 Amdt 2 P&W JT9D Aft Engine Mount Tangential Link (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/B747/157 Amdt 1 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/B747/157 Amdt 2 P&W JT9D Aft Engine Mount Tangential Link 1/2010

Applicability:

Model 747 series aeroplanes with line positions 1 to 668, powered by Pratt & Whitney JT9D series engines except JT9D-70.

Requirement:

Terminating action in accordance with the technical requirements of paragraph (b) of FAA AD 99-20-09 Amdt 39-11339.

Note:  Boeing Service Bulletins 747-71-2206 and 747-71A2277 Revision 2, or later Revisions, refer.

Compliance:

Prior to initial issue of an Australian certificate of airworthiness.

This Amendment becomes effective on 8 January 2010.

Background:

The tangential link upper bolt was found to have backed out following lubrication of the threads and/or inadequate nut torque which allowed the nut to rotate and disengage.  The original issue of this Directive nominated FAA AD 96-03-01 and became effective on 13 March 1996.

Amendment 1 specified Revision 1 of FAA AD 96-03-01 and became effective on
20 June 1996.

This Amendment specifies FAA AD 99-20-09 which superseded 96-03-01 and specified mandatory terminating action.

Mike Higgins
Delegate of the Civil Aviation Safety Authority

5 January 2010