AD/B767/138 Amdt 3 Nacelle Strut Midspar Fitting (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/B767/138 Amdt 2 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 767 Series Aeroplanes

AD/B767/138 Amdt 3 Nacelle Strut Midspar Fitting 13/2005

Applicability:

Model 767-200, -300, and -300F series aircraft, as listed in Boeing Service Bulletin 767-54A0101 Revision 4, dated 10 February 2005, or later FAA approved revision.

Requirement:

Action in accordance with the technical requirements of FAA AD 2005-19-23 Amdt 39-14288.

Note:  Boeing Service Bulletins 767-54A0101 Revision 1, Revision 3, and Revision 4, or later FAA approved revisions, refer.

Compliance:

As specified in the Requirement document, with a revised effective date of
22 December 2005.

This Amendment becomes effective on 22 December 2005.

Background:

The FAA received a report of a cracked inboard midspar fitting on a number two nacelle strut of a General Electric powered aircraft.  This crack was due to fatigue and occurred much earlier than predicted by Boeing analysis.  The actions specified by this Directive are intended to prevent fatigue cracking in the primary strut structure and reduced structural integrity of the strut, which could result in separation of the strut and engine.

Amendment 1 introduced a Boeing Service Bulletin Information Notice, which removed certain aircraft from applicability.

Amendment 2 expanded the area on which the inspections are required.

Amendment 3 is issued in response to a new FAA AD, which was prompted by a report of a crack in a closeout angle that covers the two aft-most fasteners in the lower tang of the midspar fitting; and the discovery of a crack in the lower tang of the midspar fitting under the cracked closeout angle.

The original issue of this Airworthiness Directive became effective on 12 July 2001.

David Villiers
Delegate of the Civil Aviation Safety Authority

7 November 2005