Ad/Pc-12/53 - Pitch Trim Actuator Attachment Parts (Cth)

AIRWORTHINESS DIRECTIVE

For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (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.

Pilatus PC-12 Series Aeroplanes

AD/PC-12/53 Pitch Trim Actuator Attachment Parts 11/2008 DM

Applicability:

PC-12, PC-12/45 and PC-12/47 aircraft, all serial numbers.

Requirement:

1.    Amend the approved aircraft maintenance program to incorporate the latest revision of the Airworthiness Limitations section contained in Pilatus PC-12 document 12-A-04-00-00-00A-000A-A, dated 20 June 2008 or later approved revision.

2.    For aircraft with Pitch Trim Actuator parts that have accumulated or exceeded 9900 Flight Hours, replace the parts with serviceable units.

3.    Accomplish tasks described in PC-12 AMM Chapter 4.

Note:  EASA AD 2008-0163, dated 27 August 2008 refers.

As an Alternative Method of Compliance to requirement 1 of this AD, operators may use the CD version of the reference Pilatus PC-12 document, revision 10, dated
1 March 2008, which incorporates the 20 November 2007 version of PC-12 AMM Chapter 4 and the corresponding version of Chapter 5.

Compliance:

1.    Within 30 days of the effective date of this AD.

2.    Within next 100 flight hours or 2 months after the effective date of this AD, whichever occurs first.

3.    In accordance with the thresholds and intervals indicated in Pilatus PC-12 document 12-A-04-00-00-00A-000A-A, dated 20 June 2008 or later approved revision.

This Airworthiness Directive becomes effective on 10 September 2008.

Background:

Based on the result of a fatigue life evaluation for the pitch trim actuator attachment, a new life limit of 10,000 flight hours is introduced for the pitch trim actuator attachment parts.  This Airworthiness Directive requires the implementation of the latest revision of the PC-12 AMM Chapter 4 - Airworthiness Limitations, including the new life for the pitch trim actuator attachment parts.

In addition to the new life limit of 10,000 hours on the attachment parts, the revision to the airworthiness limitations section incorporates the following:

• Time between overhaul (TBO) for the pitch trim actuator is reduced from 6,000 hours TIS or 5 years, whichever occurs first, to 5,000 hours time in service (TIS) or 5 years, whichever occurs first.
• The life limit for the pitch trim actuator is increased from 10,000 hours TIS or 13,500 flights, whichever occurs first, to 20,000 hours TIS or 27,000 flights, whichever occurs first.

David Villiers
Delegate of the Civil Aviation Safety Authority

29 August 2008