DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[4910-13-P] 

[Docket No. F AA-2012-0520; Directorate Identifier 2002-NE-43-AD; Amendment 

39-17273; AD 2012-24-03] 

RIN 2120-AA64 

Airworthiness Directives; Turbomeca S.A. Turboshaft Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are superseding an existing airworthiness directive (AD) for all 

Turbomeca S.A. Arriel lA, lAl, 1A2, lB, lC, 1C1, 1C2, 1D, 1Dl, IE, lE2, lK, lKI, 

1 S, and 1 S 1 turboshaft engines. That AD currently requires initial and repetitive visual 

inspections for erosion caused by dust ingestion and, if necessary, cleaning of the gas 

generator (module M03). This new AD requires determining the engine history; 

performing a one-time visual inspection of the axial compressor for erosion; 

performing initial and repetitive cleaning of the gas generator hollow shaft; and replacing 

the rear bearing if the amount of dust collected during cleaning exceeds 8 grams. This 

AD also includes an optional terminating action. This AD was prompted by in-service 

experience which has shown that dust inside the gas generator hollow shaft may be found 

when the axial compressor wheel has less erosion than initially assessed. We are issuing 

this AD to prevent an unbalance of the gas generator rotating assembly, which may lead 

to gas generator rear bearing failure, and uncommanded engine shutdown. 

DATES: This AD is 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 the AD as of [INSERT DATE 35 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

ADDRESSES: For service information identified in this AD, contact Turbomeca S.A., 

40220 Tarnos, France; phone: 33 05 59 74 40 00; telex: 570 042; fax: 33 05 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.!.!Ov; 

or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday 

through Friday, except Federa l holidays. The AD docket contains this AD, 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 Wl2-140, 

1200 New Jersey A venue SE., Washington, DC 20590. 

FOR FURTHER INFORMATION CONTACT: Rose Len, Aerospace Engineer, 

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

Executive Park, Burlington, MA 0 1803; phone: 781-238-7772; fax : 781-238-7199; email: rose.len@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Discussion 

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to 

supersede AD 2003-12-14, Amendment 39-13 199 (68 FR 36900, June 20, 2003). That 

AD applies to the specifi ed products. The NPRM published in the Federal Register on 

July 25, 2012 (77 FR 43550). That NPRM proposed to require determining the engine 

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history; performing a one-time visual inspection of the axial compressor for erosion; 

performing initial and repetitive cleaning of the gas generator hollow shaft; and replacing 

the rear bearing if the amount of dust collected during cleaning exceeds 8 grams. That 

NPRM also included an optional terminating action. That NPRM also removed 

Turbomeca S.A. Arriel IE and I K turbos haft engines from the applicability section of the 

AD. The IE engine is no longer in service. The 1 K engine is not an FAA validated 

engme. 

Comments 

We gave the public the opportunity to pat1icipate in developing this AD. The 

following presents the comments received on the proposal and the FAA's response to 

each comment. 

Request to Ease Requir·ements When Barrier Filters Used Continuously 

Charles E. Greenberg requested that the FAA consider modifying the AD to 

accommodate operators of helicopters with barrier filter installations for the engine 

intakes. If operator records can show that specific serial number engines have always 

operated with filtered air, the requirement for cleaning the gas generator hollow shaft 

should be superseded by a requirement to maintain records of operation with barrier filter 

protection. The commenter stated that no dirt can be ingested by an engine downstream 

of the filter, as long as the barrier filter has never gone into bypass mode. 

We disagree. The FAA cannot anticipate all of the available barrier filter designs 

installed on helicopter models. Each batTier filter design and helicopter combination 

would require its own assessment of the filter's use and effectiveness. We did not change 

the AD. 

However, the substantiated continuous use of a barrier filter may be proposed as 

an alternative method of compliance (AMOC) to this AD, using the standard AMOC 

request procedure. 

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Conclusion 

We reviewed the relevant data, considered the comment received, and determined 

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

Costs of Compliance 

We estimate that this AD will affect about 1,421 engines installed on helicopters 

of U.S. registry. We also estimate that it will take about 24 work-hours per engine to 

inspect and clean the gas generator module. The average labor rate is $85 per work-hour. 

A replacement gas generator rear bearing would cost about $4,128 per engine and take 

about 8 work-hours to replace. Based on these figures, we estimate the cost of the AD on 

U.S. operators to be $2,898,840. 

Authority for this Rulcmaking 

Title 49 of the United States Code specifies the FAA's authority to issue rules on 

aviation safety. Subtitle I, Section 106, describes the authority ofthe 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 VII, 

Part A, Subpart III, Section 4470 I, "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 

because it addresses an unsafe condition that is li kely to exist or develop on products 

identified in this rulemaking action. 

Regulatory Findings 

We have 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 

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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 that this AD: 

( 1) Is not a "significant regulatory action" under Executive Order 12866, 

(2) Is not a "significant rule" under DOT Regulatory Policies and Procedures 

( 44 FR 11034, February 26, 1979), 

(3) Will not affect intrastate aviation in Alaska, 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 Pa rt 39 

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. 

Adoption of the Amendment 

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

amends 14 CFRpart 39 as follows: 

PART 39 - AIRWORT HINESS 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) 2003-12-

14, Amendment 39-13199 (68 FR 36900, June 20, 2003), and adding the following new 

AD: 

2012-24-03 T urbomeca S.A.: Amendment 39-17273; DocketNo. FAA-2012-0520; 

Directorate Identifier 2002-NE-43-AO. 

(a) Effective Da te 

This airworthi ness directive (AD) is effective [INSERT DATE 35 DAYS AFTER 

DATE OF PUBLICATION IN THE FEDERAL REGISTER]. 

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(b) Affected ADs 

This AD supersedes AD 2003-1 2-1 4, Amendment 39-1 3199 (68 FR 36900, June 

20, 2003). 

(c) Applicability 

This AD applies to all Turbomeca S.A. Aniel lA, lAl, 1A2, IB, lC, !Cl , 1C2, 

lD, l Dl , 1E2, lKl, lS, and lSI turboshaft engines that have not incorporated 

Turbomeca S.A. Modification TU360. 

(d) Unsafe Condition 

This AD was prompted by in-service experi ence showing that dust inside the gas 

generator hollov., shaft may be found when the axial compressor wheel has less erosion 

than initially assessed. We are issuing this AD to prevent an unbalance of the gas 

generator rotating assembly, which may lead to deterioration of the gas generator rear 

bearing and uncommanded engine shutdown. 

(e) Compliance 

Comply with this AD within the compliance times specified, unless already done. 

(1) Within 50 engine hours after the effective date of this AD, determine the 

engine history and perform the maintenance actions at the specified schedules. Use 

paragraphs l .A. and 2.A. through 2.C. ofTurbomeca S.A. Alert Mandatory Service 

Bulletin (MSB) No. A292 72 0230, Version C, dated February 29,2012 to perfonn the 

maintenance actions and to establish the cleaning schedule. 

(2) If during any of the cleanings, the c;lust weight collected inside the gas 

generator hollow shaft is more than 8 grams, replace the gas generator rear bearing before 

further fl ight. 

(3) After the effective date of this AD, if there are any changes in accordance with 

paragraph l.A.( l)(a) l.3 ofTurbomeca S.A. Alert MSB No. A292 72 0230, Version C, 

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dated February 29, 20 12, withi n 50 engine hours time-in-service after such a change, 

accomplish the actions as specified in paragraphs (e)(l) and (e)(2) of this AD. 

(4) After the effecti ve date of this AD, do not install any gas generator (module 

M03) on an engine unless it is in compli ance with this AD. 

(5) After the effective date of this AD, do not install any gas generator rear 

bearing that has operated on an engine with a hollow shaft that has been found to have a 

dust weight more than 8 grams. 

(f) Optional Terminating Action 

As optional terminating action to the repetitive actions in this AD, modify the 

engine by incorporating Turbomeca S.A. Modification TU360. 

(g) Alternative Methods of Compliance (AMOCs) 

The Manager, Engine Certification Office, may approve AMOCs for this AD. Use 

the procedures found in 14 CFR 39. 19 to make your request. 

(h) Related Information 

(1) For more information about this AD, contact Rose Len, Aerospace Engineer, 

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

Executive Park, Burlington, MA 0 1803; phone: 781 -238-7772; fax: 781-238-7199; email: rose.len@faa.gov. 

(2) Refer to European Aviation Safety Agency AD 20 12-0071, dated April 26, 

20 12, and Turbomeca S.A. Alert MSB No. A292 72 0230, Version C, dated February 29, 

2012, for related information. 

(i) 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 I CFR 

pa11 51. 

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(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. Alert Mandatory Service Bulletin No. A292 72 0230, Version 

C, dated February 29, 2012. 

(ii) Reserved. 

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

Turbomeca S.A., 40220 Tarnos, France; phone: 33 05 59 74 40 00; telex: 570 042; fax: 

33 05 59 74 45 15. 

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

Directorate, 12 New England Executive Park, Burlington, MA. For infom1ation 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 November 20, 2012. 

Robert J. Ganley, 

Acting Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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