AD/A330/4 Amdt 2 THSA Operational Life Limit (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/A330/4 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.

Airbus Industrie A330 Series Aeroplanes

AD/A330/4 Amdt 2 THSA - Operational Life Limit 3/2008

Applicability:

All Model A330 aircraft, all serial numbers.

Requirement:

Action in accordance with the requirements of EASA AD 2007-0309.

Note:  Airbus Service Bulletins A330-27-3052, A330-27-3085, A330-27-3137, and A330-27-3093, original issues, or a later EASA approved revision, refer.

Compliance:

As specified in the Requirement document.

This Amendment becomes effective on 13 March 2008.

Background:

The operational life limits of aircraft flight controls actuators and in particular of the Trimmable Horizontal Stabiliser Actuator (THSA) are not addressed by the definition of the structural life limits of Safe Life items as defined in the Airworthiness Limitations Section Part 1.  This Directive requires THSA modification upon reaching the calculated operational life limit.

Amendment 1 increased the life limit for certain part number THSA following further test results.

Amendment 2 is issued in response to a new EASA AD, which takes into account the latest THSA test results by increasing the life limit for part number 47172-300, and adding the new life limits for new part numbers 47172-500 and 47172-510.

David Villiers
Delegate of the Civil Aviation Safety Authority

1 February 2008