AD/CF34/18 Master Variable Geometry (VG) Actuators (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.

General Electric Turbine Engines - CF34 Series

AD/CF34/18 Master Variable Geometry (VG) Actuators 20/2010

Applicability:

General Electric Company CF34 engines as specified in FAA AD 2005-07-09.

Requirement:

Unless already accomplished, perform the initial review and action in accordance with the requirements of FAA AD 2005-07-09.

Repeat the review and action in accordance with the requirements of FAA AD
2005-07-09.

Later revisions to GE Alert Service Bulletin No CF34-8E-AL S/B 75-A0001, Revision 3 dated February 14, 2005, approved by the United States Federal Aviation Administration (FAA) as an Alternate Method of Compliance (AMOC) to FAA AD 2005-07-09, are considered acceptable for compliance with the equivalent Requirements of this AD.

Compliance:

As specified in the Requirement Document with a revised effective date of
31 October 2010.

This Airworthiness Directive becomes effective on 31 October 2010.

Background:

This AD is issued to prevent dual-channel electrical signal faults in the VG master actuator, which will cause an un-commanded reduction of thrust to idle with a subsequent loss of the ability to advance thrust above idle.  This could result in a multi-engine loss of thrust if dual-channel faults occur on more than one engine simultaneously.

Mike Higgins
Delegate of the Civil Aviation Safety Authority

5 October 2010