AD 2007-24-10 Airworthiness Directives; Turbomeca Arriel 2S1 and 2S2 Turboshaft Engines

This AD applies to Turbomeca Arriel 2S1 and 2S2 turboshaft engines, all serial numbers that have a hydro mechanical unit (HMU) installed that was manufactured before December 8, 2006, or repaired/overhauled before December 8, 2006. These engines are installed on, but not limited to, Sikorsky S-76C helicopters. Reason (d) European Aviation Safety Agency (EASA) AD No. 2007-0063, dated March 3, 2007, states: During assembly of a new HP/LP fuel pump, the drain screw on the fuel filter unit failed when it was tightened to the torque value specified in the assembly schedule (12 Nm). Investigation of the screw showed that it was fully conforming to its specification, in terms of both dimensions and material. The mechanical calculations show, however, that a torque value of 12 Nm is too high for this screw, exceeding the elastic limit of the material. Failure of the affected screw could cause a fuel leak, resulting in an engine flame-out or engine fire.

Unless already done, within 30 HMU operating hours or 45 days after the effective date of this AD, whichever occurs first, replace the fuel filter drain screw with a new one and tighten it to an effective torque of 6.5 Nm, using Turbomeca Mandatory Service Bulletin (MSB) No. 292 73 2824, dated February 1, 2007. FAA AD Differences (f) This AD differs from the EASA AD and/ or service information as follows: (1) EASA AD No. 2007-0063 requires compliance with the AD within 30 HMU operating hours, but not later than 15 April 2007, whichever occurs first after the effective date of that AD. (2) This AD, written later, requires compliance within 30 HMU operating hours or 45 days after the effective date of this AD, whichever occurs first. 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 2007-0063, dated March 8, 2007, for related information. (i) Contact Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: Christopher.spinney@faa.gov ; telephone (781) 238-7175; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (j) You must use Turbomeca Mandatory Service Bulletin No. 292 73 2824, dated February 1, 2007, to do the actions required by this AD. (k) 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. (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 service information 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 November 20, 2007. Peter A. White, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. E7-23031 Filed 11-28-07; 8:45 am] BILLING CODE 4910-13-P

Unless already done, within 30 HMU operating hours or 45 days after the effective date of this AD, whichever occurs first, replace the fuel filter drain screw with a new one and tighten it to an effective torque of 6.5 Nm, using Turbomeca Mandatory Service Bulletin (MSB) No. 292 73 2824, dated February 1, 2007. FAA AD Differences (f) This AD differs from the EASA AD and/ or service information as follows: (1) EASA AD No. 2007-0063 requires compliance with the AD within 30 HMU operating hours, but not later than 15 April 2007, whichever occurs first after the effective date of that AD. (2) This AD, written later, requires compliance within 30 HMU operating hours or 45 days after the effective date of this AD, whichever occurs first. 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 2007-0063, dated March 8, 2007, for related information. (i) Contact Christopher Spinney, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: Christopher.spinney@faa.gov ; telephone (781) 238-7175; fax (781) 238-7199, for more information about this AD. Material Incorporated by Reference (j) You must use Turbomeca Mandatory Service Bulletin No. 292 73 2824, dated February 1, 2007, to do the actions required by this AD. (k) 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. (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 service information 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 November 20, 2007. Peter A. White, Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. E7-23031 Filed 11-28-07; 8:45 am] BILLING CODE 4910-13-P