[Docket No. F AA-2015-5539; Directorate Identifier 2015-NE-37-AD] 

RIN 2120-AA64 

Airworthiness Directives; Turbomeca S.A. Turboshaft Engines AGENCY: Federal Aviation Administration (FAA). DOT. ACTION: Notice of proposed rnlemaking (NPRM). 

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

Turbomeca S.A. Arriel 2E turboshaft engines. This proposed AD was prompted by 

reports of fuel flow non-conformities found during acceptance tests of Arriel 2E hydro-mechanical metering units (HMUs). This proposed AD would require removing 

the pre-TU 193 adjusted high-pressure/low-pressure (HP/LP) pump and metering valve 

assembly and replacing it with a part that is eligible for installation. This proposed AD 

would also require replacing the constant delta-pressure (delta-P) diaphragm of the fuel 

metering valve. We are proposing this AD to prevent failure of the delta-P diaphragm, 

which could result in an uncommanded in-flight shutdown 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 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 

20590-0001. 
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, 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. F AA-2015-5539 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 infonnation. 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: Kyle Gustafson, Aerospace Engineer, 

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

Executive Park, Burlington, MA 01803; phone: 781-238-7183; fax: 781-238-7199; email: 

kyle.gustafson@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. 

Include "Docket No. F AA-2015-5539; Directorate Identifier 2015-NE-37-AD" at the 

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

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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 

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

the Member States of the European Community, has issued EASA AD 2015-0213, dated 

October 16,2015 (referred to hereinafter as "the MCAI"), to correct an unsafe condition 

for the specified products. The MCAI states: 

Fuel flow non-conformities were found during reception tests of 

ARRIEL 2E Hydraulic Mechanical Metering Unit (1-lMU). 

Investigation and instrumented tests revealed instabilities on the 

additional check valve. These instabilities lead to hydraulic pulses. 

All HMU installed on ARRlEL 2E and 2N engines could present 

these instabilities. 

This condition, if not corrected, could lead to life reduction of the delta pressure valve diaphragm, and consequently, an 

uncommanded engine power increase, or an uncommimded in 

flight shutdown, possibly resulting in an emergency landing. 

This proposed AD applies to Arriel 2E engines only. There are no Arriel 2N 

engines installed on aircraft of U.S. registry. 

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

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

F AA-2015-5539. 

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valve. 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 NPRM. 

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 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-TU 193 adjusted HP/LP pump and metering valve assembly and 

replacing it with a part that is eligible for installation. This NPRM would also require 

replacing the constant del ta-P diaphragm of the fuel metering valve. 

Costs of Compliance 

We estimate that this proposed AD affects 12 engines installed on helicopters of 

U.S. registry. We also estimate that it would take about 2 hours per engine to comply 

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

$13,400 per engine. Based on these figures, we estimate the cost of this proposed AD on 

U.S. operators to be $162,840. 

Authority for This Rulemaking 

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

aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. 

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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 likely to exist or develop on products 

identified in this rulernaking 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 

goverrunent. 

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. 

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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 adding the follmving new airworthiness directive 

(AD): 

Turbomeca S.A.: Docket No. FAA-2015-5539; Directorate Identifier 2015-NE-37-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 Turbomeca S.A. Arriel 2E turboshaft engines that have a 

pre-TU 193 adjusted high-pressure/low-pressure (HP/LP) pump and metering valve 

assembly, installed. 

(d) Reason 

This AD was prompted by reports offue1 flow non-conformities found during 

acceptance tests of Arriel2E hydro-mechanical metering units. We are issuing this AD to 

prevent failure of the constant delta-pressure (delta-P) diaphragm of the fuel metering 

valve, which could result in an ru1commanded in-flight shutdown and damage to the 

helicopter. 

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of this AD, whichever occurs later: 

(i) remove from service the adjusted HP/LP pump and metering valve assembly 

and replace with a part that is eligible for installation, and 

(ii) replace the constant diaphragm of the fuel metering valve. 

(2) Reserved. 

(f) Installation Prohibition 

After the effective date of this AD, do not install into any engine any TU 193 

adjusted HP/LP pump and metering valve assembly, nor install onto any helicopter any 

engine that has a pre-TU 193 adjusted HP/LP pump and metering valve assembly. 

(g) 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. 

(h) Related Information 

(1) For more information about this AD, contact Kyle Gustafson, Aerospace 

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

England Executive Park, Burlington, MA 01803; phone: 781-238-7183; fax: 781-238-

7199; email: kyle.gustafson@faa.gov. 

(2) Refer to MCAI European Aviation Safety Agency AD 2015-0213, dated 

October 16, 2015, for more infommtion. You may examine the MCAI in the AD docket 

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

No. FAA-2015-5539. 

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S.A., 40220 Tamos, France; phone: 33 (0)5 59 74 40 00; fax: 33 (0)5 59 74 45 15. 

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

Directorate, 12 New England Executive Park, Burlington, J\.1A. For information on the 

availability of this material at the FAA, call781-238-7125. 

Issued in Burlington, Massachusetts, on December 18,2015. 

Atm C. Mollica, 

Acting Directorate Manager, Engine & Propeller Directorate, Aircraft Certification Service. 

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