2006-26-07: A simultaneous interruption of the lubrication on both engines may lead to a double non-commanded in-flight shutdown.

2006-26-07 Turbomeca: Amendment 39-14865; Docket No. FAA-2006-26138; Directorate Identifier 2006-NE-38-AD. Effective Date (a) This airworthiness directive (AD) becomes effective January 18, 2007. Affected ADs (b) None. Applicability (c) This AD applies to Turbomeca Model Arrius 2B1, 2B1A, and 2B2 turboshaft engines that do not embody modification TU122. These engines are used on, but not limited to Eurocopter EC135 T1 and T2 helicopters. Reason (d) European Aviation Safety Agency (EASA) AD, 2006-0142, dated May 29, 2006 states: Investigations of incidents which occurred on ARRIUS 2 turboshaft engines have revealed the interruption of engine lubrication further [due] to oil passage blockage within the lubrication unit check valve. This blockage comes from the excessive swelling of the check valve piston o-ring. The level of swelling of the o-ring depends on the class of the oil used (Standard (STD) or High-Thermal Stability (HTS)) and the engine operating time. This phenomenon only affects ARRIUS 2 engines which do not embody modification Tu122 (i.e.: check-valve piston without o-ring). A simultaneous interruption of the lubrication on both engines may lead to a double non-commanded in-flight shutdown. The oil usually being the same on both engines, available data put into evidence that this risk has to be considered and that measures to restore the level of safety have to be imposed on ARRIUS 2 engines without modification Tu122 embodied. The condition described in the EASA AD can lead to a forced autorotation landing or an accident. Actions and Compliance (e) Unless already done, do the following actions. (1) Replace the check-valve piston o-ring according to paragraph 2 of Turbomeca Alert Service Bulletin No A319 79 2832, Update 1, dated April 3, 2006, within the next 50 operating hours when the number of operating hours is greater than: (i) 300 hours for engines operating with HTS-class oil andengines for which the history of the oils used is not available or engines which used to operate with HTS-class oil and which no longer do so. (ii) 450 hours for engines operating with STD class-oil since their introduction into service. (2) Repeat operation of paragraph (1): (i) Every 300 hours for engines operating with HTS-class oil and engines for which the history of the oils used is not available or engines which used to operate with HTS-class oil and which no longer do so. (ii) Every 500 hours for engines operating with STD class-oil since their introduction into service. FAA AD Differences (f) None. Other FAA AD Provisions (g) The following provisions also apply to this AD: (1) Alternative Methods of Compliance (AMOCs): The Manager, Engine Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. (2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service. (3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act, the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120- 0056. Related Information (h) Contact Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone (781) 238- 7175; fax (781) 238-7199 for more information about this AD. (i) Refer to the EASA Mandatory Continuing Airworthiness Information (MCAI) Airworthiness Directive 2006-0142, dated May 29,2006, and Turbomeca Service Bulletin A319 79 2122, dated March 14, 2006, for related information. Material Incorporated by Reference (j) You must use Turbomeca Alert Service Bulletin A319 79 2832, Update 1, dated April 3, 2006, to do the actions required by this AD, unless the AD specifies otherwise. (1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51. (2) For service information identified in this AD, contact Turbomeca, 40220 Tarnos, France; Telephone (33) 05 59 74 40 00; fax (33) 05 59 74 45 15. (3) You may review copies at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.