Document ID: chunk:federal_register_of_legislation:F2009L01129:body:0:p1
Version: federal_register_of_legislation:F2009L01129
Segment Type: other
Provision Reference: 
Character Range: 0–3268

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