[Docket No. F AA-2015-8257; Directorate Identifier 2015-NE-36-AD] 

RIN 2120-AA64 

Airworthiness Directives; Turbomeca S.A. Turboshaft Engines AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking (NPRM). 

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

Turbomeca S.A. MAKILA 2A and MAKILA 2A1 turboshaft engines. This proposed AD 

was prompted by two occurrences of crack initiation on a ferrule of the diffuser. This 

proposed AD would require repetitive diffuser inspections and replacement of those 

diffusers that fail inspection. We are proposing this AD to prevent rupture of the ferrule 

of the diffuser, which could result in engine fire 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 Tarnos, France; phone: (33) 05 59 74 40 00; fax: (33) 05 59 74 45 15. You may 

view this service information at the FAA, Engine & Propeller Directorate, 1200 District 

Avenue, Burlington, MA 01803. 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://W\VW.regulations.gov by 

searching for and locating Docket No. FAA-2015-8257; 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: Brian Kierstead, Aerospace Engineer, 

Engine Certification Office, FAA, Engine & Propeller Directorate, 1200 District Avenue, 

Burlington, MA 01803; email: brian.kierstead@faa.gov; phone: 781-238-7772; fax: 781-

238-7199. 

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Include "Docket No. F AA-2015-8257; Directorate Identifier 2015-NE-36-AD'' at the 

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

economic, environmental, and energy aspects of this proposed AD. We will consider all 

comments received by the closing date and may amend this proposed AD 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 proposed AD. 

Discussion 

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

the Member States of the European Community, has issued EASA AD 2015-0209, dated 

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

for the specified products. The MCAI states: 

Two occurrences of crack initiation were reported on a ferrule of 

diffuser part number (PIN) 0298210100, which propagated and led 

to the ferrule rupture. The investigation shows in both cases that 

the ruptured ferrule contacted and punctured the main fuel supply 

line, resulting in a fuel leak. This condition, if not detected and 

corrected, could lead to an engine fire, consequently triggering an 

uncommanded engine in flight shut down, possibly resulting in an 

emergency landing. Prompted by these occurrences, Turbomeca 

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http://www.regulations.gov by searching for and locating Docket No. FAA-2015-8257. 

Related Service Information under 1 CFR Part 51 

Turbomeca S.A. has issued Alert Mandatory Service Bulletin (MSB) No. A298 

72 2832, Version B, dated October 12, 2015. The Alert MSB describes procedures for 

repetitive inspections of the affected diffuser and depending on findings, accomplishment 

of the corrective action(s). 

Turbomeca S.A. has issued Service Bulletin (SB) No. 298 72 2833, Version A, 

dated July 29,2015. The SB identifies post-TU52 HP gas generator modules that have 

been released with a new ferrule after repair or overhaul in a Repair Center. When 

applying Alert Mandatory Service Bulletin (MSB) No. A298 72 2832, it is necessary to 

know if an HP gas generator module released by a Repair Center is equipped with a new 

ferrule. 

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 

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AD would require repetitive inspections of the affected diffuser and depending on 

findings, accomplishment of the corrective action(s). 

Costs of Compliance 

We estimate that this proposed AD affects 10 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. Based on these figures, 

we estimate the cost of this proposed AD on U.S. operators to be $1,700. 

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 rulernaking 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 

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

identified in this rulemaking action. 

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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. 

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(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 Turbomeca S.A. MAKILA 2A aod MAKILA 2Al turboshaft 

engine models with a high-pressure (HP) gas generator module (M03) that has 

modification (mod) TU 52 installed. 

(d) Reason 

This AD was prompted by two occurrences of crack initiation on a fenule of the 

diffuser, which propagated and led to the ferrule rupture. We are issuing this AD to 

prevent rupture of the ferrule of the diffuser, which could result in engine fire and 

damage to the helicopter. 

(e) Actions and Compliance 

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

(1) Borescope inspect the centrifugal diffuser ferrule, part number (PIN) 

0298210100, prior to the femlle accumulating 700 hours, time since new or time since 

replacement or within 30 hours from the effective date of this AD, whichever is later. Use 

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inspection. 

(3) If any crack, loss of contact between the ferrule and diffuser axial vane, or any 

contact between the injection manifold supply pipe and the diffuser ferrule is found, 

remove the diffuser case and replace the ferrule with a part eligible for installation. 

(f) Credit for Previous Actions 

You may take credit for the actions required by paragraph (e) of this AD if you 

performed Turbomeca S.A. MSB No. 298 72 2832, Version A, dated September 3, 2015 

before the effective date of this AD. 

(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 Brian Kierstead, Aerospace 

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

District Avenue, Burlington, MA 01803; phone: 781-238-7772; fax: 781-238-7199; 

email: brian.kierstead@faa.gov;. 

(2) Refer to MCAI European Aviation Safety Agency AD 2015-0209, dated 

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

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(h)(5) of this proposed AD. 

(4) Turbomeca S.A. Service Bulletin (SB) No. 298 72 2833, Version A, dated 

July 29, 2015, can be obtained fmm Turbomeca S.A., using the contact information in 

paragraph (h)(5) ofthis proposed AD. 

(5) For service information identified in this proposed AD, contact Turbomeca 

S.A., 40220 Tarnos, France; phone: (33) 05 59 74 40 00; fax: (33) 05 59 74 45 15. 

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

Directorate, 1200 District A venue, Burlington, MA 01803. For information on the 

availability of this material at the FAA, call 781-238-7125. 

Issued in Burlington, Massachusetts, on February 29,2016. 

Colleen M. D'Alessandro, 

Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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