AD/SD3-60/68 Amdt 2 Elevator Trim Tab Balance Weight Brackets (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/SD3-60/68 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.

Short SD3-60 Series Aeroplanes

AD/SD3-60/68 Amdt 2 Elevator Trim Tab Balance Weight Brackets 9/2007

Applicability:

Model SD3-60 aircraft, all serial numbers.

Requirement:

Action in accordance with the requirements of EASA Emergency AD 2007-0107-E.

Note:  Shorts Service Bulletins SD360-55-20 Revision 2 and SD360-55-A21
Revision 1, or later EASA approved revisions, refer.

Compliance:

As specified in the Requirement document, with a revised effective date of
30 August 2007.

This Amendment becomes effective on 30 August 2007.

Background:

During a routine structural inspection, an operator found that the elevator tab balance weight brackets on both trim tabs were cracked.  Examination of the cracked brackets by the aircraft manufacturer determined that they were not manufactured in conformity to the approved design standard.  The non-conformity has the potential to greatly reduce the fatigue life of the brackets, causing premature crack initiation and failure.

Amendment 1 was prompted by a new UK CAA AD, which cancelled previously issued ADs 009-06-2003 (AD/SD3-60/66) and G-2004-0032.  This action was in response to an investigation by the Type Certificate Holder which revealed the new brackets were not manufactured in conformity with the applicable design data.

Amendment 2 is issued in response to a new EASA AD, which addresses the issue of ‘reworked’ brackets.  It also combines the necessary corrective actions into a single AD that assures the correct standard of elevator trim tab mass balance weight brackets are installed.

David Villiers
Delegate of the Civil Aviation Safety Authority

20 July 2007