AD/A330/32 Amdt 3 Main Landing Gear Retraction Actuator Piston Rod (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/A330/32 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.

Airbus Industrie A330 Series Aeroplanes

AD/A330/32 Amdt 3 Main Landing Gear Retraction
Actuator Piston Rod 12/2006

Applicability:

AIRBUS A330 aircraft, models -201, -202, -203, -223, -243, -301, -302, -303, -321,
-322, -323, -341, -342 and -343 except those on which AIRBUS modification 52980 has been embodied in production or AIRBUS Service Bulletin (SB) AA330-32-3180 Revision 01 or AIRBUS SB A330-32-3174 Revision 02 has been embodied in-service.

Requirement:

Action in accordance with EASA AD 2006-0302 dated 5 October 2006.

Note:  EASA AD 2006-0302 supersedes DGAC AD F-2005-098.

Compliance:

In accordance with EASA AD 2006-0302 with a revised effective date of
23 November 2006.

Compliance with Paragraph 6 of EASA 2006-0302 has a revised date of
31 January 2008.

This Amendment becomes effective on 23 November 2006.

Background:

During an approach phase, the flight crew of an A330 aircraft had to perform a free-fall extension of the left hand main landing gear.  Rupture of the piston rod of the left hand main landing gear retraction actuator was observed near to the rod attachment point.  The inspection revealed the presence of corrosion and many cracks in the vicinity of the break.  This rupture led to an un-damped extension of the landing gear, which resulted in very high forces throughout the whole gear at full extension.  The structural integrity of the landing gear was compromised.  This situation, if not corrected, could lead to a potentially hazardous event during extension and landing.

Amendment 1 of this AD was in response to another incident occurring since the issue of the original issue of this Directive.  This amendment required more frequent visual inspection of the gear retract actuator.

Amendment 2 of this AD required additional work to be carried out including draining of fluid from the internal volume of the retraction actuator piston rod.  It has been determined that the presence of water in the internal volume can present a potential source of stress in the piston rod.

Amendment 3 changes the interval for the fluid drain procedure which has been extended. Removes the need of a visual inspection provided that a fluid drain and a one-time ultrasonic inspection of the entire piston rod is carried out. Adds a new one-time ultrasonic longitudinal and circumferential inspection of the full piston rod and mandates a new design piston rod as a terminating action.

The original issue of this AD became effective on 15 April 2004.

Amendment 1 of this AD became effective on 30 September 2004.

Amendment 2 of this AD became effective on 1 September 2005

James Coyne
Delegate of the Civil Aviation Safety Authority

13 October 2006