AD 2010-19-06 Airworthiness Directives; Turbomeca Arriel 1 Series Turboshaft Engines

This AD applies to Turbomeca Arriel 1A, 1A1, 1B, 1C, 1C1, 1C2, 1D, 1D1, and 1S1 turboshaft engines that have incorporated Modification TU347. These engines are installed on, but not limited to, Eurocopter AS350 series, AS365 and SA365 series, Sikorsky S-76A series and S-76C series helicopters. Reason (d) Metallurgical non-conformities have been found when performing quality inspections during production of Arriel 1 gas generator (GG) second stage turbine discs introduced by Turbomeca Modification TU347 (P/N 0 292 25 040 0). Analysis has concluded that the approved life limit of the post-TU347 GG second stage turbine disc needs to be reduced to 2,500 GG cycles. We are issuing this AD to prevent failure of the gas generator second stage turbine disc which could result in the release of high energy debris and damage to the helicopter.

Unless already done, do the following: (1) For gas generator second stage turbine discs, part number (P/N) 0 292 25 040 0 that do not have the “CFR” marking, remove from service before exceeding 2,500 cycles-in-service (CIS) since-new or within 20 CIS from the effective date of this AD, whichever occurs later. (2) For gas generator second stage turbine discs, P/N 0 292 25 040 0 that have the “CFR” marking, remove from service before exceeding 3,500 CIS since-new. Gas Generator Second Stage Turbine Installation Prohibition (3) After the effective date of this AD, for gas generator second stage turbine discs, P/N 0 292 25 040 0 that do not have the “CFR” marking, and have 2,500 or more CIS since-new, do not install into any engine. (4) After the effective date of this AD, for gas generator second stage turbine discs, P/N 0 292 25 040 0 that have the “CFR” marking, and have 3,500 or more CIS since-new, do not install into any engine. FAA AD Differences (f) This AD differs from the Mandatory Continuing Airworthiness Information (MCAI) and/or service information as follows: (1) European Aviation Safety Agency (EASA) AD 2010-0101R1, dated August 4, 2010, requires second stage turbine discs with fewer than 2,500 CIS to be removed upon accumulating 2,500 CIS. (2) EASA AD 2010-0101R1, dated August 4, 2010, requires revising the approved aircraft maintenance program to reflect the new reduced life limit of 2,500 CIS. Alternative Methods of Compliance (AMOCs) (g) 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 (h) Refer to EASA AD 2010-0101R1, dated August 4, 2010, and Turbomeca Alert Mandatory Service Bulletin No. A292 72 0831, Version B, dated July 7, 2010, for related information. Contact Turbomeca, 40220 Tarnos, France; telephone 33 05 59 74 40 00, fax 33 05 59 74 45 15, for a copy of this service information. (i) Contact Richard Woldan, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: richard.woldan@faa.gov; telephone (781) 238-7136; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (j) None. Issued in Burlington, Massachusetts, on September 10, 2010. Francis A. Favara, Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 2010-23100 Filed 9-20-10; 8:45 am] BILLING CODE 4910-13-P

Unless already done, do the following: (1) For gas generator second stage turbine discs, part number (P/N) 0 292 25 040 0 that do not have the “CFR” marking, remove from service before exceeding 2,500 cycles-in-service (CIS) since-new or within 20 CIS from the effective date of this AD, whichever occurs later. (2) For gas generator second stage turbine discs, P/N 0 292 25 040 0 that have the “CFR” marking, remove from service before exceeding 3,500 CIS since-new. Gas Generator Second Stage Turbine Installation Prohibition (3) After the effective date of this AD, for gas generator second stage turbine discs, P/N 0 292 25 040 0 that do not have the “CFR” marking, and have 2,500 or more CIS since-new, do not install into any engine. (4) After the effective date of this AD, for gas generator second stage turbine discs, P/N 0 292 25 040 0 that have the “CFR” marking, and have 3,500 or more CIS since-new, do not install into any engine. FAA AD Differences (f) This AD differs from the Mandatory Continuing Airworthiness Information (MCAI) and/or service information as follows: (1) European Aviation Safety Agency (EASA) AD 2010-0101R1, dated August 4, 2010, requires second stage turbine discs with fewer than 2,500 CIS to be removed upon accumulating 2,500 CIS. (2) EASA AD 2010-0101R1, dated August 4, 2010, requires revising the approved aircraft maintenance program to reflect the new reduced life limit of 2,500 CIS. Alternative Methods of Compliance (AMOCs) (g) 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 (h) Refer to EASA AD 2010-0101R1, dated August 4, 2010, and Turbomeca Alert Mandatory Service Bulletin No. A292 72 0831, Version B, dated July 7, 2010, for related information. Contact Turbomeca, 40220 Tarnos, France; telephone 33 05 59 74 40 00, fax 33 05 59 74 45 15, for a copy of this service information. (i) Contact Richard Woldan, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: richard.woldan@faa.gov; telephone (781) 238-7136; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (j) None. Issued in Burlington, Massachusetts, on September 10, 2010. Francis A. Favara, Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 2010-23100 Filed 9-20-10; 8:45 am] BILLING CODE 4910-13-P