DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA-2015-3753; Directorate Identifier2015-NE-26-AD] RIN 2120-AA64 Airworthiness Directives; Turbomeca S.A. Turboshaft Engines AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice ofproposed rulemaking (NPRM). [4910-13-P]

SUMMARY: We propose to supersede airworthiness directive (AD) 2016-04-12 that applies to certain Turbomeca S.A. Arriel2B, 2B1, 2C, 2C1, 2C2, 2D, 2E, 2S1, and 2S2 turboshaft engines. AD 2016-04-12 requires spectrometric oil analysis (SOA) inspection ofthe engine accessory gearbox (AGB), and, depending on the results, removal ofthe engine AGB. Since we issued AD 2016-04-12, we determined that wear inspections of the engine AGB cover are also required. This proposed AD would require initial and repetitive inspections ofthe AGB, and wear inspections ofthe engine AGB cover. We are proposing this AD to prevent failure ofthe engine AGB, uncommanded in-flight shutdown (IFSD), damage to the engine, and damage to the helicopter. DATES: We must receive comments on this proposed AD by [INSERT DATE 60 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 and 11.45, by any ofthe following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Followthe instructions for submitting comments.

• Fax: 202-493-2251.• Mail: U.S. Department ofTransportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 NewJersey Avenue SE., Washington, DC 20590.

• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5p.m., Monday through Friday, except Federal holidays. For service information identified in this proposed AD, contact Turbomeca S.A., 40220 Tamos, 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, 1200 District Avenue, Burlington, MA. For information on the availability ofthis material at the FAA, call 781-238-7125. 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-2015-3753; 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 proposed AD, the mandatory continuing airworthiness information, regulatory evaluation, any comments received, and other information. The address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt. FOR FURTHERINFORMATION CONTACT: Philip Haberlen, Aerospace Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7770; fax: 781-238-7199; email: philip.haberlen@faa.gov. SUPPLEMENTARY INFORMATION: Comments Invited We invite you to send any written relevant data, views, or arguments about this NPRM. Send your comments to an address listed under the ADDRESSES section. 2Include "Docket No. FAA-2015-3753; Directorate Identifier 2015-NE-26-AD" at the beginning ofyour comments. We specifically invite comments onthe overall regulatory, economic, environmental, and energy aspects ofthis NPRM. We will consider all comments received by the closing date and may amend this NPRMbecause ofthose comments. We will post all comments we receive, without change, to http://www

.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this NPRM. Discussion OnFebruary 18, 2016, we issued AD 2016-04-12, Amendment 39-18406 (81 FR 12583, March 10, 2016), ("AD 2016-04-12") for certain Turbomeca S.A. Arriel2B, 2B1, 2C, 2C1 , 2C2, 2D, 2E, 2S1 , and 2S2 turboshaft engines. AD 2016-04-12 requires an SOA inspection, and, depending on the results, removal ofthe engine AGB. AD 2016- 04-12 resulted from a report ofan uncommanded IFSD ofan Arriel 2S2 engine caused by rupture ofthe 41-tooth gear, which forms part ofthe bevel gear in the engine AGB. We issued AD 2016-04-12 to prevent failure ofthe engine AGB, uncommanded IFSD, damage to the engine, and damage to the helicopter. Actions Since AD 2016-04-12 Was Issued Since we issued AD 2016-04-12, Turbomecarecommended that an engine AGB

cover wear inspection be performed. Also, the European Aviation Safety Agency issued AD 2016-0055, dated March 17, 2016, which requires initial and repetitive SOA inspections ofthe AGB and initial and repetitive wear inspections ofthe engine AGB

cover.

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### Related Service Information under 1 CFRPart 51 Turbomeca S.A. has issued Mandatory Service BulletinNo. 292 72 2861, Version C, dated March 9, 2016. The service information describes procedures for performing periodic SOA and wear inspections ofthe engine AGB. This service information is reasonably available because the interested parties have access to it through their normal

course ofbusiness orby the means identified inthe ADDRESSES section. 

### FAA's Determination We are proposing this NPRM because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in otherproducts ofthe same type design. 

### Proposed AD Requirements This NPRM would require initial and repetitive SOA, wear inspections ofthe engine AGB cover, and AGB replacement based on the results ofthe inspections. 

### Costs ofCompliance We estimate that this proposed AD affects 250 engines installed on helicopters of U.S. registry. We also estimate that it would take 0.5 hours per engine to perform the SOA and 1hour to perform the engine AGB cover wear inspection. The average labor

rate is $85 per hour. Required parts for inspection and analysis cost about $3,179 per engine. We estimate that 5 engines will require AGB replacement at a cost of$44,397 per engine. We also estimate that it would take about 2 hours to replace the engine AGB. Based on these figures, we estimate the cost ofthis proposed AD on U.S. operators to be $1,049,460. 

### Authority for this Rulemaking Title 49 ofthe United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority ofthe FAA Administrator.



### 4Subtitle VII, Aviation Programs, describes in more detail the scope ofthe Agency's authority. We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701 , "General requirements." Under that section, Congress charges the FAA with promoting safe flight ofcivil 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 ofthat authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action. Regulatory Findings We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect onthe States, on the relationship betweenthe national Government and the States, or on the distribution ofpower and responsibilities among the various levels ofgovernment. For the reasons discussed above, I certify that the proposed regulation: (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 Alaskato the extent that itjustifies making a regulatory distinction, and (4) Will not have a significant economic impact, positive ornegative, on a substantial number ofsmall entities under the criteria ofthe Regulatory Flexibility Act. List ofSubjects in 14 CFRPart 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.



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### The Proposed Amendment Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFRpart 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. 

### §39.13 [Amended] 2. The FAA amends§ 39.13 by removing airworthiness directive (AD) 2016-04-12, Amendment 39-18406 (81 FR 12583, March 10, 2016) ("AD 2016-04-12"), and adding the following newAD: 

### Turbomeca S.A.: DocketNo. FAA-2015-3753 ; Directorate Identifier 2015-NE-26-AD. 

### (a) Comments Due Date We must receive comments by [INSERT DATE 60 DAYS AFTERDATE OF PUBLICATION IN THE FEDERAL REGISTER]. 

### (b) Affected ADs This AD supersedes AD 2016-04-12. 

### (c) Applicability This AD applies to Turbomeca S.A. Arriel 2B, 2B1, 2C, 2C1, 2C2, 2D, 2E, 2S 1, and 2S2 turboshaft engines with an engine accessory gearbox (AGB), part number 0292120650, with a machined front casing. 

### (d) Unsafe Condition This AD was prompted by a report ofan uncommanded in-flight shutdown (IFSD) ofan Arriel 2S2 engine caused byrupture ofthe 41-tooth gear, which forms part ofthe bevel gear in the engine AGB. We are issuing this AD to prevent failure ofthe engine AGB, uncommanded IFSD, damage to the engine, and damage to the helicopter.

6(e) Compliance Comply with this AD within the compliance times specified, unless already done. (1) Initial Spectrometric Oil Analysis (SOA) and Engine AGB Cover Wear Inspection (i) Perform an SOA and an engine AGB cover wear inspection before the engine AGB, module 

### MO 1, exceeds 850 engine hours (EH) since new or since last overhaul (SLO), or within 50 EH after April 14, 2016, or before the next flight after the effective date ofthis AD, whichever occurs later. (ii) Reserved. (2) Repetitive Inspection Intervals (i) Repeat the SOA within every 100 EH since

_ the last SOA. (A) For all affected engines, ifthe last SOA was performed before the effective date ofthis AD, and the aluminum concentration level is 0.8 parts per million (p/m) or greater, perform a wear inspection ofthe engine AGB cover within 50 EHs since last SOA or before the next flight after the effective date ofthis AD, whichever occurs later. (B) For all affected engines, ifthe last SOA was performed after the effective date ofthis AD, and the aluminum concentration level is 0.8 p/m or greater, perform a wear inspection ofthe engine AGB cover within 20 EH since the last SOA. (ii) For Arriel2E engines, repeat the engine AGB cover wear inspection within every 800 EH since last inspection (SLI) ifthe SOA indicated the aluminum concentration level is less than 0.8 p/m. (iii) For all affected engines, except for Arriel2E engines, repeat the engine AGB

cover wear inspection within every 600 EH SLI ifthe SOA indicated the aluminum concentration level is less than 0.8 p/m. (3) Inspection Criteria

7(i) Use paragraph 2.4.2.1 and 2.4.2.2 ofTurbomecaMandatory Service Bulletin (MSB) No. 292 72 2861, Version C, dated March 9, 2016, to do the inspections required by paragraphs (e)(l) and (2) ofthis AD. (ii) Reserved. (4) CorrectiveActions Based on the Results ofthe Most Recent Wear Inspection (i) Ifthe wearmeasured from the mostrecent wear inspection is 0.15 mm or less,

no further action is required. However, you must still comply with the repetitive inspection requirements ofparagraph (e)(2) ofthis AD. (ii) Ifthe most recent wear inspection was performed while the engine was in service, and the wear is greater than 0.15 mm, do the following: (A) Ifthe wear measured from the most recent wear inspection is greater than 0.15 mm, but 0.30 mm or less, remove the engine AGB from service within 200 EH SLI and replace with a part eligible for installation. (B) Ifthe wear measured from the most recent wear inspection is greaterthan 0.30 mm, but 0.40 mm or less, remove the engine AGB from service within 25 EH SLI and replace with a part eligible for installation. (C) Ifthe wear measured from the most recent wear inspection is greaterthan 0.40 mm, remove the engine AGB from service before further flight and replace with a part eligible for installation. (iii) Ifthe most recent wear inspection was performed onthe engine during an engine shop visit, and the wear is greater than 0.15 mm, remove the engine AGB before further flight and replace with a part eligible for installation. (f) Definition Forthe purpose ofthis AD, an engine shop visit is defined as the induction ofan engine into the shop for maintenance involving the separation ofany major mating 8engine flanges, exceptthat the separation ofengine flanges solely for the purposes of transportation without subsequent engine maintenance does not constitute an engine shop visit. 

### (g) Alternative Methods ofCompliance (AMOCs) The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD. Use the procedures found in 14 CPR 39.19 to make yourrequest. You may email your request to: ANE-AD-AMOC@faa.gov. 

### (h) Related Information (1) Formore information about this AD, contact Philip Haberlen, Aerospace Engineer, Engine Certification Office, FAA, Engine & PropellerDirectorate, 1200 District Avenue, Burlington, MA 01803; phone: 781-238-7770; fax: 781-238-7199; email: philip.haberlen@faa.gov. (2) Referto MCAI European Aviation Safety Agency AD 2015-0055, dated March 17, 2016, for more information. You may examine the MCAI inthe AD docket on the Internet at http://www.regulations.gov by searching for and locating it in DocketNo. FAA-2015-3753. (3) Turbomeca S.A. MSB No. 292 72 2861, Version C, dated March 9, 2016, can be obtained from Turbomeca S.A., using the contact information in paragraph (h)(4) of this AD. (4) For service information identified in this AD, contact Turbomeca S.A., 40220 Tamos, France; phone: 33 0 5 59 74 40 00; fax: 33 0 5 59 74 45 15. (5) You may viewthis service information at the FAA, Engine & Propeller Directorate, 1200 District Avenue, Burlington, MA. For information onthe availability of this material at the FAA, call 781-238-7125.

9Issued in Burlington, Massachusetts, on June 8, 2016.

Colleen M. D'Alessandro, Manager, Engine & Propeller Directorate, Aircraft Certification Service.

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