[Docket No. FAA-2006-25970; Directorate Identifier 99-NE-12-AD; Amendment 39-

18426; AD 2016-05-08] 

RlN 2120-AA64 

Airworthiness Directives; Turbomeca S.A. Turboshaft Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: We are superseding airworthiness directive (AD) 2006-23-17 for certain 

Turborneca S.A. Turmo IV A and IV C turboshaft engines. AD 2006-23-17 required 

repetitive inspections of the centrifugal compressor intake wheel (inducer) blades for 

cracks and corrosion, replacement of parts that fail inspection, and replacement of the TU 

197 standard centrifugal compressor. This AD requires the same inspections, but at 

revised intervals, adds the replacement of the TU 215 standard centrifugal compressor, 

and requires replacement of pmts that fail inspection. This AD was prompted by a 

centrifugal compressor inducer blade loss. This AD was also prompted by a Turborneca 

S.A. review of the engine service experience and their detennination that more frequent 

borescope inspections (BSis) are required on engines not modified to the TU 191, TU 197, 

or TU 224 standard. We are issuing this AD to prevent failure of the centrifugal 

compressor inducer, which could lead to an uncontained blade release, damage to the 

engine, and damage to the airplane. 
PUBLICATION IN THE FEDERAL REGISTER]. 

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

40220 Tarnos, 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. It is also available on the Internet at http://www.regulations.gov by 

searching for and locating Docket No. F AA-2006-25970. 

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-2006-25970; 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, 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 W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590. 

FOR FURTHER JNFORMA TION CONTACT: Kenneth Steeves, Aerospace Engineer, 

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

2 
We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to 

supersede AD 2006-23-17, Amendment 39-14829 (71 FR 66664, November 16, 2006), 

("AD 2006-23-17"). AD 2006-23-17 applied to the specified products. The NPRM 

published in the Federal Register on November 25, 2015 (80 FR 73681). The NPRM 

proposed to require the same inspections, but at revised intervals, add the replacement of 

the TU 215 standard centrifugal compressor, and require replacement of parts that fail 

inspection. 

Comments 

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

received no comments on the NPRM (80 FR 73681, November 25, 2015). 

Conclusion 

We reviewed the available data and determined that air safety and the public 

interest require adopting this AD as proposed. 

Related Service Information under 1 CFR Part 51 

We reviewed Turbomeca S.A. Alert Mandatory Service Bulletin (MSB) No. A249 

72 0100, Version H, dated May 21, 2015. The Alert MSB describes procedures for the 

inspection and replacement of the centrifugal compressor inducer blades. 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. 

3 
labor rate is $85 per hour. Parts cost about $40,000 per engine. Based on these figures, we 

estimate the cost of this AD on U.S. operators to be $202,400. 

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 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 

because it addresses an unsafe condition tl1at is likely to exist or develop on products 

identified in this rulernaking action. 

Regulatory Findings 

This AD will not have federalism implications under 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. 

4 
(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. 

Adoption of the Amendment 

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

amends part 39 of the Federal Aviation Regulations (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. I 06(g), 40113,44701. 

§39.13 [Amended] 

2. The FAA amends§ 39.13 by removing airworthiness directive (AD) 2006-23-

17, Amendment 39-14829 (71 FR 66664, November 16, 2006) ("2006-23-I 7"), and 

adding the following new AD: 

2016-05-08 Turbomeca S.A.: Amendment 39-18426; Docket No. FAA-2006-25970; 

Directorate Identifier 99-NE-12-AD. 

5 
This AD replaces AD 2006-23-17. 

(c) Applicability 

This AD applies to Turbomeca S.A. Turmo IV A and IV C turboshaft engines. 

(d) Unsafe Condition 

This AD was prompted by a centrifugal compressor inducer blade loss. We are 

issuing this AD to prevent failure of the centrifugal compressor inducer, which could lead 

to an uncontained blade release, damage to the engine, and damage to the airplane. 

(e) Compliance 

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

(1) Remove the TU 197 and TU 215 standard centrifugal compressors and install 

the TU 224 standard centrifugal compressor, within 30 days after the effective date of this 

AD. 

(2) Perform initial and repetitive ultrasonic inspections (Uis) or eddy current 

inspections (ECis) of the centrifugal compressor (inducer). Use Accomplishment 

Instructions, paragraph 6.B.(l)(b) ofTurbomeca S.A. Alert Mandatory Service Bulletin 

(MSB) No. A249 72 0100, Version H, dated May 21,2015 to do the inspections. Use 

Appendix I ofTurbomeca S.A. Alert MSB No. A249 72 0 I 00, Version H, dated May 21, 

2015 for the schedule of inspections. 

6 
H, dated May 21, 2015 for the schedule of inspections. 

(4) If, during any inspection required by paragraphs (e)(2) or (e)(3) of this AD, any 

crack, corrosion, or other damage is detected on the inducer, then before next flight, 

replace the centrifugal 

(5) Accomplishment of a UI or ECI of the centrifugal compressor inducer, required 

by paragraph (e)(2) of this AD, is acceptable in lieu of a BSI required by paragraph (e)(3) 

of this AD for that engine. 

(6) Replacement of a centrifugal compressor required by paragraph (e)( 4) of this 

AD, does not constitute terminating action for the repetitive inspections required by 

paragraphs (e)(2) and (e)(3) of this AD. 

(f) Credit for Previous Actions 

You may take credit for the inspections and corrective actions required by 

paragraphs ( e )(2) and ( e )(3) of this AD, if you performed the inspections and corrective 

actions before the effective date of this AD, using Turbomeca S.A. Alert MSB No. A249 

72 0100, Version G, or an earlier version. 

(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. 

7 
kenneth.steeves@faa.gov. 

(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 1 CFR 

part 51. 

(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 (MSB) No. A249 72 0100, 

Version H, dated May 21,2015. 

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

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

15. 

( 4) You may view this service information at 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. 

(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, 

8 
Colleen M. D' Alessandro, 

Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

9