AD 2009-09-03 Airworthiness Directives; Turbomeca S.A. Arriel 2B and 2B1 Turboshaft Engines

This AD applies to Turbomeca S.A. Arriel 2B and 2B1 turboshaft engines. These engines are installed on, but not limited to, Eurocopter AS 350 B3 and EC 130 B4 helicopters. Reason (d) Several cases of Gas Generator Turbine (HP Turbine) blade rearward displacement have been detected during borescope inspection or in repair centre following engine disassembly. Two of them resulted in blade rubs between the rear face of the fir-tree roots and the rear bearing support cover. High HP blade rearward displacement can potentially result in blade release due to fatigue of the blade, which would cause an uncommanded in-flight engine shutdown. We are issuing this AD to prevent an uncommanded in-flight engine shutdown which could result in an emergency autorotation landing or, at worst, an accident.

Unless already done, do the following actions: Initial Inspection (1) Perform an initial HP turbine borescope inspection according to Turbomeca S.A. Mandatory Service Bulletin (MSB) No. 292 72 2825, dated April 5, 2007 as follows: (i) For engines with fewer than 500 hours and 450 cycles since new or since the last HP turbine borescope inspection, inspect before reaching 600 hours or 500 cycles, whichever occurs first. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm. (ii) For the remaining engines, inspect within the next 100 hours. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm. Repetitive Inspections (2) Perform repetitive HP turbine borescope inspections according to Turbomeca S.A. MSB No. 292 72 2825, dated April 5, 2007: (i) Within 600 hours or 500 cycles from the previous inspection, whichever occurs first, if the rearward displacement of the turbine blades was less than 0.2 mm. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm. (ii) Within 100 hours of the previous inspection if the rearward displacement of the turbine blades was between 0.2 mm and 0.5 mm. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm. FAA AD Differences (f) For clarification, we restructured the actions and compliance wording of this AD. (g) We deleted the Turbomeca reporting requirement from the AD, since we determined that the reporting requirement was unnecessary. Alternative Methods of Compliance (AMOCs) (h) 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. Related Information (i) Refer to EASA Airworthiness Directive 2007-0109, dated April 19, 2007, and Turbomeca S.A. MSB No. 292 72 2825, dated April 5, 2007, for related information. (j) Contact James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: james.lawrence@faa.gov; telephone (781) 238-7176; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (k) You must use Turbomeca S.A. Mandatory Service Bulletin No. 292 72 2825, dated April 5, 2007, to do the actions required by this AD, unless the AD specifies otherwise. (l) 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. (m) You may review copies at the FAA, New England Region, 12 New England Executive Park, Burlington, MA; or 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/cfr/ibr-locations.html. Issued in Burlington, Massachusetts, on April 16, 2009. Peter A. White, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. E9-9333 Filed 4-24-09; 8:45 am] BILLING CODE 4910-13-P

Unless already done, do the following actions: Initial Inspection (1) Perform an initial HP turbine borescope inspection according to Turbomeca S.A. Mandatory Service Bulletin (MSB) No. 292 72 2825, dated April 5, 2007 as follows: (i) For engines with fewer than 500 hours and 450 cycles since new or since the last HP turbine borescope inspection, inspect before reaching 600 hours or 500 cycles, whichever occurs first. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm. (ii) For the remaining engines, inspect within the next 100 hours. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm. Repetitive Inspections (2) Perform repetitive HP turbine borescope inspections according to Turbomeca S.A. MSB No. 292 72 2825, dated April 5, 2007: (i) Within 600 hours or 500 cycles from the previous inspection, whichever occurs first, if the rearward displacement of the turbine blades was less than 0.2 mm. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm. (ii) Within 100 hours of the previous inspection if the rearward displacement of the turbine blades was between 0.2 mm and 0.5 mm. Replace HP turbine modules with rearward turbine blade displacement greater than 0.5 mm. FAA AD Differences (f) For clarification, we restructured the actions and compliance wording of this AD. (g) We deleted the Turbomeca reporting requirement from the AD, since we determined that the reporting requirement was unnecessary. Alternative Methods of Compliance (AMOCs) (h) 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. Related Information (i) Refer to EASA Airworthiness Directive 2007-0109, dated April 19, 2007, and Turbomeca S.A. MSB No. 292 72 2825, dated April 5, 2007, for related information. (j) Contact James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: james.lawrence@faa.gov; telephone (781) 238-7176; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (k) You must use Turbomeca S.A. Mandatory Service Bulletin No. 292 72 2825, dated April 5, 2007, to do the actions required by this AD, unless the AD specifies otherwise. (l) 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. (m) You may review copies at the FAA, New England Region, 12 New England Executive Park, Burlington, MA; or 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/cfr/ibr-locations.html. Issued in Burlington, Massachusetts, on April 16, 2009. Peter A. White, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. E9-9333 Filed 4-24-09; 8:45 am] BILLING CODE 4910-13-P