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 - CT7 Series AD/CT7/13 No.3 Bearing 4/2009 Applicability: General Electric Company (GE) CT7-8A turboshaft engines that have a serial number (SN) listed in Table 1 of this AD. Note 1: These engines are installed on, but not limited to, Sikorsky S92 helicopters. Table 1 - Affected Engines by Serial Number Engine Serial Number 947205 947215 947230 947243 947254 947265 947206 947217 947232 947244 947255 947274 947207 947218 947233 947245 947256 947277 947208 947219 947235 947247 947258 947278 947209 947220 947238 947248 947260 947279 947210 947221 947240 947249 947261 947280 947211 947223 947241 947250 947262 947284 947212 947225 947242 947253 947263 947285 947214 947228 Requirement: No further action is required if: - The engine has a SN that is not listed in Table 1 of this AD; or - The engine has a SN listed in Table 1 of this AD, but the engine log specifies that the front frame was flushed and the No. 3 bearing was replaced. 1. For engines with a SN listed in Table 1 of this AD, remove the engine from service and flush the front frame and replace the No. 3 bearing. GE CT7-8 Shop Manual, GEK 10517, contains information on replacing the No. 3 bearing and GE Aircraft Engines Service Bulletin No. CT7-8 S/B 72-0017, Revision 02, dated 14 May 2008, or earlier revision, contains information on flushing the front frame and replacing the No. 3 bearing. 2. Do not install any No. 3 bearing removed as detailed in Requirement 1 of this AD. Note 2: FAA AD2008-26-02 Amdt 39-15768 dated 9 December 2008 refers. Compliance: For Requirement 1 - Within 6,200 cycles-since-new. For Requirement 2 - After the effective date of this AD. This Airworthiness Directive becomes effective on 9 April 2009. Background: This AD results from investigation for the root causes of two failures of the No. 3 bearing. The issuing of this AD is intended to prevent failure of the No. 3 bearing due to contamination by aluminium oxide, which could result in a possible in-flight shutdown of the engines and loss of control or forced landing of the aircraft. James Coyne Delegate of the Civil Aviation Safety Authority 26 February 2009