DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA-2016-2859; Directorate Identifier 2016-NE-04-AD[ 

RlN 2120-AA64 

Ainvorthiness Directives; Turbomeca S.A. Turboshaft Engines 

AGENCY: Federal Aviation Administration (FAA). DOT. 

ACTION: Notice of proposed rulemaking (NPRM). 

[4910-13-P[ 

SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 

Turbomeca S.A. ArriellD and lDl turboshaft engines with a pre-modification (mod) 

TU357 gas generator module (M03), installed. This proposed AD was prompted by 

reports of divergent rubbing between the piston shaft small diameter labyrinth and the 

rear bearing support. This proposed AD would require removing the pre-modification 

(mod) TU357 gas generator module (M03) and replacing with a part eligible for 

installation. We are proposing this AD to prevent failure of the labyrinth seal and engine, 

in-flight shutdown, and loss of control of 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 by any of the following methods: 

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the 

instructions for submitting comments. 

• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 

New Jersey Avenue SE., West Building Ground Floor, Room W12-140, Washington, DC 

20590-000 I. 
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., 

Monday through Friday, except Federal holidays. 

• Fax: 202-493-2251. 

For service information identified in this NPRlVI, 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 A venue, 

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. F AA-2016-2859; or in person at the Docket 

Operations office 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 (MCAI), the 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 FURTHER INFORMATION 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 

NPRlVI. Send your comments to an address listed under the ADDRESSES section. 

Include "Docket No. F AA-2016-2859; Directorate Identifier 2016-NE-04-AD" at the 

beginning of your comments. We specifically invite comments on the overall regulatory, 

2 
economic, environmental, and energy aspects of this NPRM. We will consider all 

comments received by the closing date and may amend this NPRM based on those 

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 with FAA personnel 

concerning this NPRM. 

Discussion 

The European Aviation Safety Agency (EASA), which is the Technical Agent for 

the Member States ofthe European Community, has issued EASA AD 2016-0009, dated 

January 13,2016 (referred to hereinafter as "the MCAI"), to correct an unsafe condition 

for the specified products. The MCAI states: 

Some cases of divergent rubbing between the piston shaft small 

diameter labyrinth and the rear bearing support have been reported. 

This condition, if not corrected, could lead to an uncommanded 

engine in-flight shutdown. 

You may obtain further information by examining the MCAI in the AD docket on 

the Internet at http://www.regulations.gov by searching for and locating Docket No. 

FAA-2016-2859. 

Related Service Information 

Turbomeca S.A. has issued Mandatory Service Bulletin (MSB) No. 292 72 1357, 

Version B, dated November 12,2015. The MSB describes procedures for installing a 

post-modification (mod) TU357 gas generator module (M03). This service information 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 NPRlvf. 

3 
FAA's Determination and Requirements of This Proposed AD 

This product has been approved by the aviation authority of France, and is 

approved for operation in the United States. Pursuant to our bilateral agreement with the 

European Community, EASA has notified us of the unsafe condition described in the 

MCAI and service information referenced above. We are proposing this NPRM because 

we evaluated all information provided by EASA and determined the unsafe condition 

exists and is likely to exist or develop on other products of the same type design. This 

NPRM: would require removing the pre-modification (mod) TU357 gas generator module 

(M03) and replacing with a part eligible for installation. 

Costs of Compliance 

We estimate that this proposed AD affects 426 engines installed on helicopters of 

U.S. registry. We also estimate that it would take about 40 hours per engine to comply 

with this proposed AD. The average labor rate is $85 per hour. Required parts cost about 

$16,500 per engine. Based on these figures, we estimate the cost of this proposed AD on 

U.S. operators to be $8,477,400. 

Authority for This Rulemaking 

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 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 VII, 

Part A, Subpart III, Section 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 authority 

4 
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 proposed AD would not have federalism implications 

under Executive Order 13132. This proposed AD would 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 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 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, Incorporation by reference, Safety. 

The Proposed Amendment 

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

proposes to amend 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. 

5 
§ 39.13 [Amended] 

2. The FAA amends§ 39.13 by adding the following new airworthiness directive 

(AD): 

Turbomeca S.A.: Docket No. FAAw2016w2859; Directorate Identifier 2016-NE-04-AD. 

(a) Comments Due Date 

We must receive comments by [INSERT DATE 60 DAYS AFTER DATE OF 

PUBLICATION IN THE FEDERAL REGISTER]. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to all Arriel 1 D and 1 D 1 turbo shaft engines with a premodification (mod) TU357 gas generator module (M03), installed. 

(d) Reason 

This AD was prompted by reports of divergent rubbing between the piston shaft 

small diameter labyrinth and the rear bearing support. We are issuing this AD to prevent 

failure of the labyrinth seal and engine, in-flight shutdown, and loss of control of the 

helicopter. 

(e) Actions and Compliance 

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

(I) Within 4 months or 240 engine operating hours after the effective date of this 

AD, whichever occurs later, remove the pre-modification (mod) TU357 gas generator 

module (M03) from service and replace with a part eligible for installation. 

(2) Reserved. 

6 
(I) 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 

your request to: ANE-AD-AMOC@faa.gov. 

(g) Related Information 

(1) For more information about this AD, contact Philip Haberlen, Aerospace 

Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 

District A venue, Burlington, MA 01803; phone: 781-238-7770; fax: 781-23 8-7199; 

email: philip.haberlen@faa.gov. 

(2) Refer to MCAl European Aviation Safety Agency AD 2016-0009, dated 

January 13,2016, for more information. You may examine the MCAI in the AD docket 

on the Internet at http://www.regulations.gov by searching for and locating it in Docket 

No. FAA-2016-2859. 

Issued in Burlington, Massachusetts, on February 18,2016. 

Ann C. Mollica, 

Acting Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

7