[Docket No. FAA-2014-0164; Directorate Identifier 2014-NE-02-AD; Amendment 

39-17973; AD 2014-19-05) 

RIN 2120-AA64 

Ainvorthiness Directives; Turbomeca S.A. Turboshaft Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are adopting a new airworthiness directive (AD) for all Turbomeca 

S.A. Arricl I A I, I A2, l B, l C, l C l, l C2, l D, l D I, I E2, I K l, IS, 1 S l. 2B, 2B 1, 2C. 

2C I, 2C2, 2S I, and 2S2 turboshaft engines. This AD requires an initial one-time 

vibration check of the engine accessory gearbox (AGB) on certain higher risk Arriel I 

and Arriel 2 model engines. This AD also requires repetitive vibration checks of the 

engine AGB for all Arriel 1 and Aniel 2 engines at every engine shop visit. This AD was 

prompted by reports ofuncommanded in-flight shutdowns on Turbomeca S.A. Arriel 1 

and Arriel 2 engines following rupture of the 41-tooth gear forming part of the 

41 /23-tooth bevel gear located in the engine AGB. We are issuing this AD to prevent 

failure of the engine AGB, which could lead to in-flight shutdown and damage to the 

engine. which may result in damage to the aircraft. 

DATES: This AD becomes effective [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION fN THE FEDERAL REGISTER]. 
40220 Tarnos, France; phone: 33 (0)5 59 74 40 00; telex: 570 042; fax: 33 (0)5 59 74 45 

15. You may view this service information at the FAA, Engine & Propeller Directorate, 

12 New England Executive Park, Burlington, MA. For information on the availability of 

this 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-2014-0164; 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 ofTransportation, Docket Operations, M-30. 

West Building Ground Floor, Room Wl2-140, 1200 New Jersey Avenue SE., Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: Mark Riley, Aerospace Engineer. 

Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New England 

Executive Park, Burlington, MA 01803; phone: 781-238-7758; fax: 781-238-7199: email: 

mark.riley@faa.gov. 

2 
the Federal Register on June 4, 2014 (79 FR 32195). The NPRM proposed to correct an 

unsafe condition for the specified products. This AD results from an MCAI originated by 

an aviation authority of another country to identify and correct an unsafe condition on an 

aviation product. The MCAI states: 

Comments 

Several cases of uncommanded in-flight shut-down (IFSD) have 

been reported on ARRIEL 1 or ARRIEL 2 engines following 

rupture of the 41-tooth gear forming part of the 41/23 tooth bevel 

gear located in the accessory gearbox (AGB) within engine module 

MOl. 

Results of subsequent investigations showed that the meshing 

quality ofthe bevel gear may have contributed to tooth rupture. 

The rupture of the AGB 41-tooth gear may lead to loss of driving 

of equipment essential to engine operation. 

This condition if not detected and corrected, could lead to an 

uncommanded engine in-flight shut-down and may ultimately lead 

to an emergency landing. 

We gave the public the opportunity to participate in developing this AD. We 

considered the comment received. 

Request to Provide Sufficient Compliance Time 

One comrnenter requested that we provide sufficient time to comply with the AD. 

The commenter indicated that special tooling, to be supplied by Turbomeca, is necessary 

3 
Conclusion 

We reviewed the available data, including the comment received, and determined 

that air safety and the public interest require adopting this AD as proposed. 

Costs of Compliance 

We estimate that this AD affects 1,268 engines installed on aircraft of U.S. 

registry. We also estimate that it will take about 4 hours per engine to comply with the 

inspection requirement in this AD. The average labor rate is $85 per hour. Based on these 

figures, we estimate the cost ofthis AD on U.S. operators to be $431, 120. 

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 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 ''Subtitle VIL 

Part A, Subpart III, Section 44 701: 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 authority 

4 
Executive Order 13132. This AD will not have a substantial direct effect on the States. on 

the relationship between the national government 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" Lmder 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, tncorporation by reference, Safety. 

Adoption of the Amendment 

Accordingly, under the authority delegated to me by the Administrator, the FAA 

amends 14 CFR pa11 39 as follows: 

PART 39- AIRWORTHINESS DIRECTIVES 

1. The authority citation for part 39 continues to read as follows: 

Authority: 49 U.S.C. 1 06(g), 40113, 44701. 

5 
Directorate Identifier 20 14-NE-02-AD. 

(a) Effective Date 

This AD becomes effective [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to all Turbomeca S.A. ArriellAl, 1A2, 1B, 1C, ICI, 1C2, I D. 

lDl, 1E2, lKl, IS, lSI, 2B, 2Bl, 2C, 2CI, 2C2, 2Sl, and 2S2 turboshaft engines. 

(d) Reason 

This AD was prompted by reports of uncommanded in-flight shutdowns on 

Turbomeca S.A. Arriel I and Arriel 2 engines following rupture of the 41-tooth gear 

forming the 41/23-tooth bevel gear located in the engine accessory gearbox (AGB). We 

are issuing this AD to prevent failure of the engine AGB, which could lead to in-flight 

shutdown and damage to the engine, which may result in damage to the aircraft. 

(e) Actions and Compliance 

Unless already done, do the following. 

6 
with an AGB installed with a serial number (SIN) listed in Figure 1 ofTurbomeca S.A. 

Mandatory Service Bulletin (MSB) No. 292 72 0839, Version B, dated November 25. 

2013, use paragraphs 6.A. through 6.C. ofTurbomeca S.A. MSB No. 292 72 0839, 

Version B, dated November 25,2013, to perfmm the vibration check. The reporting 

requirements in paragraphs 6.A.(l )(c), 6.A.(2)(b ), and 6.B.(l )(c) and the requirement to 

return module MOJ in paragraph 6.B.(2)(b)2_, ofTurbomeca S.A. MSB No. 292 72 0839, 

Version B, dated November 25,2013, are not required by this AD. 

(ii) For all Turbomeca S.A. Arriel 2B and 2B 1 engines, except those engines with 

an AGB installed with an SIN listed in Figure 1 ofTurbomeca MSB No. 292 72 2849, 

Version B, dated November 25,2013, use paragraphs 6.A. through 6.C. ofTurbomeca 

S.A. MSB No. 292 72 2849, Version B, dated November 25,2013, to perform the 

vibration check. The reporting requirements in paragraphs 6.A.(1)(c), 6.A.(2)(b), and 

6.B.(1 )(c), and the requirement to return module MOl in paragraph 6.B.(2)(b)2_, of 

Turbomeca S.A. MSB No. 292 72 2849, Version B, dated November 25,2013, are not 

required by this AD. 

(2) For all affected Turbomeca S.A. engines. during each engine shop visit after 

the effective date of this AD, perform a vibration check of the AGB 41 /23-tooth bevel 

gear meshing. Guidance on performing the vibration check during an engine shop visit 

7 
(f) Credit for Previous Action 

If you performed a vibration check of the AGB before the effective date of this 

AD using Turbomcca S.A. MSB No. 292 72 0839, Version A, dated September 9, 20 13: 

or MSB No. 292 72 2849, Version A, dated September 9, 2013, or during an engine shop 

visit per paragraph (e)(2) of this AD. you met the initial inspection requirement of 

paragraph (e)(l) ofthis AD. 

(g) Definition 

For the purpose of this AD, an "engine shop visit" is the induction of an engine 

into the shop for maintenance involving the separation of pairs of major mating engine 

flanges. The separation of engine flanges solely for the purpose of transportation without 

subsequent engine maintenance does not constitute an engine shop visit. 

(h) Alternative Methods of Compliance (AMOCs) 

The Manager, Engine Certification Office, FAA, may approve AMOCs to this 

AD. Use the procedures found in 14 CFR 39.19 to make your request. 

(i) Related Info rmation 

( 1) For more information about this AD, contact Mark Riley, Aerospace Engineer. 

Engine Certification Office, FAA, Engine & Propeller Directorate. 12 New England 

Executive Park, Burlington, MA 01803: phone: 781-238-7758; fax: 781-238-7199: email: 

mark.rile) @faa.gov. 

8 
0292009400, Version T; CCT No. 0292019400, Version R; CCT No. 0292019690, 

Version I; CCTNo. 029201530, Version K; CCTNo. 0292019610, Version K; CCTNo. 

0292029450, Version J; CCT No. 0292029490, Version I; CCT No. 0292029440, 

Version I; CCT No. 0292029480, Version K; CCT No. 0292029520, Version H; CCT 

No. 0292029410, Version L; CCT No. 0292029530, Version II; or Turbomeca ID No. 

383952; or Turbomeca RTD No. X 292 65 327 2, which are not incorporated by 

reference in this AD, can be obtained from Turbomeca S.A., using the contact 

information in paragraph G)(3) of this AD. 

U) Material Incorporated by Reference 

(1) The Director of the Federal Register approved the incorporation by reference 

(IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR 

part 5 1. 

(2) You must use this service information as applicable to do the actions required 

by this AD, unless the AD specifies otherwise. 

(i) Turbomeca S.A. Mandatory Service Bulletin (MSB) No. 292 72 0839, Version 

B, dated November 25,2013. 

(ii) Turbomeca S.A. MSB No. 292 72 2849, Version B, dated November 25. 

2013. 

9 
2014. 

(vi) Turbomeca S.A. Arriel2 TI No. 292 72 2850, dated November 29,2013. 

(3) For Turbomeca S.A. service information identified in this AD, contact 

Turbomeca, S.A., 40220 Tamos, France; phone: 33 (0)5 59 74 40 00; telex: 570 042; fax: 

33 (0)5 59 74 45 15. 

( 4) You may view this service information at FAA, Engine & Propeller 

Directorate, 12 New England Executive Park, Burlington, MA. For information 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 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibrlocations.html. 

Issued in Burlington, Massachusetts, on September 15, 2014. 

Colleen M. D' Alessandro, 

Assistant Directorate Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

10