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**DEPARTMENT OF TRANSPORTATION Federal Aviation Administration**  **14 CFR Part 39 [Docket No. FAA** **- 20**  **1 5**  **- 3753**  **; Directorate Identifier 20**  **1 5**  **- NE**  **- 26**  **- AD**  **; Amendment 39**  **- 18406**  **; AD 2016**  **- 04**  **- 12**  **] RIN 2120**  **- AA64**  **Airworthiness Directives; Turbomeca S.A. Turboshaft En**  **gines AGENCY:**  Federal Aviation Administration (FAA), DOT. **ACTION:** Final rule . **SUMMARY:** We are adopting a new airworthiness directive (AD) for certain Turbomeca S.A. Arriel 2B, 2B1, 2C, 2C1, 2C2, 2D, 2E , 2S1, and 2S2 turboshaft engines . This AD requires inspection, and, depending on the results, removal of the engine accessory gearbox (AGB ) . This AD was prompted by a report of an uncommanded in flight shutdown (IFSD) of an Arriel 2 engine caused by rupture of the 41 - tooth gear, which forms part of the bevel gear in the engine AGB . We are issuing this AD to prevent failure of the engine AGB, which could lead to in - flight shutdown, damage to the engine, and damage to the aircraft . **DATES:** This AD becomes effective [ INSERT DATE 35 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of [I NSERT DATE 35 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].2

**ADDRESSES:** For service informati on identified in this final rule , contact Turbomeca S.A., 40220 Tarnos, France; phone: 33 0 5 59 74 40 00; fax: 33 0 5 59 74 45 15 . You may view this service information at the FAA, Engine & Propeller Directorate, 12 00 District Avenue , Burlington, MA. For information on the availability of this material at the FAA, call 781 - 238 - 7125. Itis also available on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA - 201 5 - 3753 . **Examining the AD Docket** You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA - 201 5 - 3753 ; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday , except Federal holidays. The AD docket contains this AD , the mandatory continuing airworthiness information (MCAI), the regulatory evaluation, any

comments received, and other information. The address for the Docket Office (phone: 800 - 647 - 5527) is Document Management Facility, U.S. Department of Transportation, Docket Operations, M - 30, West Building Ground Floor, Room W12 - 140, 1200 New Jersey Avenue SE., Washington, DC 20590 . **FOR FURTHER INFORMATION CONTACT:** Philip Haberlen , Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 00 District Avenue , Burlingto n, MA 01803; phone: 781 - 238 - 7770 ; fax: 781 - 238 - 7199; email: philip.haberlen @faa.gov .3

**SUPPLEMENTARY INFORMATION: Discussion**  We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to the specified products. Th e NPRM was published in the Federal Register on November 24, 2015 (80 FR 73148 ) . Th e NPRM proposed to correct an unsafe condition for the specified products. The MCAI states :

An uncommanded in - flight shut - down (IFSD) of an ARRIEL 2 engine was reported, caused by rupture of the 41 - tooth gear, which forms part of the bevel gear of the accessory gearbox (module M01). The subsequent investigation revealed that wear on the housing of the front bearing of this gear was a major contributor to this rupture. In addition, th e investigation showed that this wear mechanism had resulted in positive Spectrometric Oil Analysis (SOA) indications before the event. This condition, if not detected and corrected, could potentially lead to further cases of IFSD, possibly resulting in an emergency landing. You may obtain further information by examining the MCAIin the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA - 201 5 - 3753 . **Comments** We gave the public the opportunity to participate in develop ing this AD. We received no comments on the NPRM ( 80 FR 73148, November 24, 2015) . **Conclusion** We reviewed the available data and determined that air safety and the public interest require adopting this AD as proposed.4

**Related Service Information**  **under 1 CFR Part 51**  Turbomeca S.A. has issued Mandatory Service Bulletin No. 292 72 2861, Version A, dated April 24, 2015. The service information describes procedures for inspecting the engine AGB . This service inform ation is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in the ADDRESSES section of this final rule . **Co s**  **ts of Compliance**  We estimate that this AD affects 250 engines installed on aircraft of U.S. registry . We also estimate that it will take about 0.5 hours per engine to compl y with the initial inspection requirement in this AD and about 2 hours per engine to remove the engine AGB . The spectrometric oil analysis kit cos ts about $79 . The average labor rate is $85 per hour. Based on these figures, we estimate the cost of this AD on U.S. operators to be $72,875. **Authority for T**  **his Rulemaking** Title 49 of the United States Code specifies the FAA’s authority to issue rules on aviation safety. Subtitle I, s ection 106, describes the authority of the FAA Administrator.

“ Subtitle VII : Aviation Programs ,” describes in more detail the scope of the Agency ’s authority . We are issuing this rulemaking under the authority described in “S ubtitle VII, P art A, S ubpart III, S ection 44701 : General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority5

because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. **Regulatory Findings** We determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national g overnment and the States, or on the distribution of power and responsibilities among the various levels of government. For the reasons discussed above, I certify this AD : (1) Is not a “significant regulatory action” under Executive Order 12866, (2) Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979), ( 3 ) Will not affect intrastate aviation in Alaska to the extent that it justifies making a regulatory

distinction, and (4 ) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility

Act. **List of Subjects in 14 CFR Part 39** Air transportation, Aircraft, Aviation safety, In corporation by reference , Safety . **Adoption of the Amendment**  Accordingl y, under the authority delegated to me by

the Administrator, the FAA amend s 14 CFR part 39 as follows: **PART 39 -**  **AIRWORTHINESS DIRECTIVES** 1. The authority citation for part 39 continues to read as follows: Authority : 49 U.S.C . 106(g), 40113 , 44701.6

**§ 39.13 [Amended]**  2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD) : 2016 - 04 - 12 Turbomeca S.A. **:** Amendment 39 - 18406 ; Docket No. FAA - 20 1 5 - 3753 ; Directorate Identifier 20 1 5 -NE - 26 - AD. **(a) Effective**  **Date** This AD becomes effective [ IN SERT DATE 35 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. **(b) Affected ADs**  None . **(c) Applicability**  This AD applies to Turbomeca S.A. Arriel 2B, 2B1, 2C, 2C1, 2C2, 2D, 2E, 2S1, and 2S2 turboshaft engines with an engine accessory gearbox (AGB), part number (P/N) 0292120650, with a machined front casing. **(d) Reason** This AD was prompted by a report of an uncommanded in - flight shutdown (IFSD) of an Arriel 2 engine caused by rupture of the 41 - tooth gear , which forms part of the bevel gear in the engine AGB . We are issuing this AD to prevent failure of the engine AGB, which could lead to IFSD , damage to the engine, and damage to the aircraft. **(e) Actions and Compliance**  Comply with this AD within the compliance times specified, unless already done. **(1) Initial Spectrometric Oil Analys is (SOA)** 7 (i) Perform an initial SOA within the compliance times given in paragraph (e)(1)(i)(A) or (e)(1)(i)(B) of this AD: (A) If the engine AGB has less than 800 engine hours (EHs) since new or since last overhaul, do an initial SOA before exceeding 850 EH s since new or since last overhaul. (B ) If the engine AGB has 800 EH s or more since new or since last overhaul, or if the EHs are unknown , do an initial SOA within 50 EH s after the effective date of this AD. (C) Use paragraphs 2.4.2.1 and 2.4.2.2 of Turb omeca S.A. Mandatory Service Bulletin (MSB) No. 292 72 2861, Version A, dated April 24, 2015 , to perform the SOA required b y paragraph (e) of this AD . (ii) Reserved. **(2) Repetitive SOA** (i) If the aluminum concentration determined from the most recent SOA is less than 0.8 parts per million (PPM), repeat the SOA required b y paragraph (e) of this AD within 100 EHs time since last anal ys is (TSLA). (ii) If the aluminum concentration determined from the most recent SOA is between 0.8 PPM and 1.4 PPM, inclusive, repeat the SOA required b y paragraph (e) of this AD within 50 EHs TSLA. Do not perform draining before doing the next SOA. (iii) If the aluminum concentration determined from the most recent SOA is greater than 1.4 PPM, remove the engine AGB from service within 50 EH s TSLA .8

**(f) Alternative Methods of Compliance (AMOCs)** The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD. Use the procedures found in 14 CFR 39.19 to make your request. You may email yo ur request to: ANE - AD - AMOC@faa.go v. **( g** **) Related Information**  (1) For more information about this AD, contact Philip Haberlen , Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 00 District Avenue , Burlingto n, MA 01803; phone: 781 - 238 - 7770 ; fax: 781 - 238 - 7199; email: philip.haberlen @faa.gov . ( 2 ) Refer to MCAI European Aviation Safety Agency AD 2015 - 0162 , dated August 6, 2015 , for more information. You may examine th e MCAIin the AD docket on the Internet at http://www.regulations.gov/#!documentDetail;D=FAA - 2015 - 3753 - 0001 . **( h**  **) Material Incorporated by Reference** (1) The Director of the Federal Register approved the incorporation b y reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use thi s service information as applicable to do the actions required by this AD, unless the AD specifies otherwise. (i) Turbomeca S.A. Mandatory Service Bulletin No. 292 72 2861, Version A, dated April 24, 2015 . (ii) Reserved .9 (3) For Turbomeca S.A. service info rmation identified in this AD, contact Turbomeca S.A., 40220 Tarnos, France; phone: 33 0 5 59 74 40 00; fax: 33 0 5 59 74 45 15 . (4) You may

view this service information at FAA, Engine & Propeller Directorate, 12 00 District Avenue , Burlington, MA. For in formation on the availability of this material at the FAA, call 781 - 238 - 7125. (5) You may

view this service information at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202 - 741 - 6 030, or go to: http://www.archives.gov/federal - register/cfr/ibr locations.html. Issued in Burlington, Massachusetts, on February 18 , 2016 .

Ann C . Mollica , Acting Manager , Engine & Propeller Directorate, Aircraft Certification Service .