2008-26-02: Electrical chip detectors

2008-26-02 General Electric Company: Amendment 39-15768. Docket No. FAA-2006-24261; Directorate Identifier 2006-NE-12-AD. Effective Date (a) This airworthiness directive (AD) becomes effective January 26, 2009. Affected ADs (b) This AD supersedes AD 2006-06-51, Amendment 39-14566. Applicability (c) This AD applies to General Electric Company (GE) CT7-8A turboshaft engines that have a serial number (SN) listed in Table 1 of this AD. 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 947262947284 947212 947225 947242 947253 947263 947285 947214 947228 Unsafe Condition (d) This AD results from investigation for the root causes of two failures of the No. 3 bearing. We are issuing this AD to prevent failure of the No. 3 bearing due to contamination by aluminum oxide, which could result in a possible in-flight shutdown of the engines and loss of control or forced landing of the aircraft. Compliance (e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done. (f) No further action is required if: (1) Your engine has a SN that is not listed in Table 1 of this AD, or (2) Your 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. Engines With SNs listed in Table 1 of This AD (g) For engines with a SN listed in Table 1 of this AD, within 6,200 cycles-since-new, 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 May 14, 2008, or earlier revision, contains information on flushing the front frame and replacing the No. 3 bearing. Prohibition Against Reinstalling a No. 3 Bearing (h) After the effective date of this AD, do not install any No. 3 bearing removed as a requirement of paragraph (g) of this AD. Alternative Methods of Compliance (i) The Manager, Engine Certification Office, FAA, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19. Related Information (j) GE CT7-8 Shop Manual, GEK 10517, and GE Aircraft Engines Service Bulletin No. CT7-8 S/B 72-0017, Revision 02, dated May 14, 2008 and earlier revisions pertainto the subject of this AD. Contact General Electric Aircraft Engines CT7 Series Turboshaft Engines, 1000 Western Ave., Lynn, MA 01910; telephone (781) 594- 6726; fax (781) 594-1583, for a copy of this service information. (k) Contact Christopher Richards, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: [email protected]; telephone (731) 238-7133; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (l) None.