
[Federal Register Volume 80, Number 227 (Wednesday, November 25, 2015)]
[Proposed Rules]
[Pages 73681-73683]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-29886]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-25970; Directorate Identifier 99-NE-12-AD]
RIN 2120-AA64


Airworthiness Directives; Turbomeca S.A. Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede airworthiness directive (AD) 2006-23-
17, which applies to certain Turbomeca S.A. Turmo IV A and IV C 
turboshaft engines. AD 2006-23-17 currently requires 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 
proposed AD would 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. We 
are proposing 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.

DATES: We must receive comments on this proposed AD by January 25, 
2016.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.

[[Page 73682]]

     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed 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, 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. FAA-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 proposed AD, the regulatory evaluation, any 
comments received and other information. The street 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: Wego Wang, Aerospace Engineer, Engine 
Certification Office, FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7134; fax: 
781-238-7199; email: wego.wang@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. FAA-2006-25970; 
Directorate Identifier 99-NE-12-AD'' at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this NPRM. We will consider all 
comments received by the closing date and may amend this NPRM because 
of 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 we 
receive about this NPRM.

Discussion

    On November 7, 2006, we issued AD 2006-23-17, Amendment 39-14829 
(71 FR 66664, November 16, 2006), (``AD 2006-23-17''), for all 
Turbomeca S.A. Turmo IV A and IV C turboshaft engines. AD 2006-23-17 
resulted from a Turbomeca S.A. review of the engine service experience 
and their determination that more frequent borescope inspections (BSIs) 
are required on engines not modified to the TU 191, TU 197, or TU 224 
standard. AD 2006-23-17 requires repetitive BSI and eddy current 
inspections (ECIs) or ultrasonic inspections (UIs) of centrifugal 
compressor intake wheel (inducer) blades and replacement of parts that 
fail inspection and replacement of the TU 197 standard centrifugal 
compressor. We issued AD 2006-23-17 to prevent centrifugal compressor 
intake wheel (inducer) blade cracks, which can result in engine in-
flight power loss, engine shutdown, or forced landing.

Actions Since AD 2006-23-17 Was Issued

    Since we issued AD 2006-23-17, a centrifugal compressor inducer 
blade loss occurred on an engine modified to TU 224 standard. This 
blade loss was due to cracks caused by impacts combined with 
significant erosion of the part not related to the TU 224 modification. 
Turbomeca S.A. has revised the inspection intervals for the centrifugal 
compressor (inducer) blades, and requires replacement of parts that 
fail inspection, and replacement of the TU 197 and TU 215 standard 
centrifugal compressors. This proposed AD would require repetitive 
BSIs, and ECIs or UIs of the centrifugal compressor inducers at revised 
intervals, replacement of parts that fail inspection, and replacement 
of the TU 197 and TU 215 standard centrifugal compressors.

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 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 of this NPRM.

FAA's Determination

    We are proposing this NPRM because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This NPRM would require repetitive BSIs, and ECIs or UIs based on 
the in-service requirements established for the various centrifugal 
compressor inducer standards, replacement of parts that fail 
inspection, and replacement of the TU 197 and TU 215 standard 
centrifugal compressors.

Costs of Compliance

    We estimate that this proposed AD affects 36 engines installed on 
airplanes of U.S. registry. We estimate that two of these engines will 
require compressor replacement. We also estimate that about 40 hours 
per engine are required to comply with this proposed AD. The average 
labor rate is $85 per hour. Parts cost about $40,000 per engine. Based 
on these figures, we estimate the cost of this proposed 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 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.

Regulatory Findings

    We have 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 that the proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,

[[Page 73683]]

    (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

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by removing airworthiness directive (AD) 
2006-23-17, Amendment 39-14829 (71 FR 66664, November 16, 2006) 
(``2006-23-17''), and adding the following new AD:

Turbomeca S.A.: Docket No. FAA-2006-25970; Directorate Identifier 
99-NE-12-AD.

(a) Comments Due Date

    The FAA must receive comments on this AD action by January 25, 
2016.

(b) Affected ADs

    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.(1)(b) of 
Turbomeca S.A. Alert Mandatory Service Bulletin (MSB) No. A249 72 
0100 Version H, dated May 21, 2015 to do the inspections. Use 
Appendix 1 of Turbomeca S.A. Alert MSB No. A249 72 0100 Version H, 
dated May 21, 2015 for the schedule of inspections.
    (3) Perform initial and repetitive borescope inspections (BSIs) 
of the centrifugal compressor inducer. Use Accomplishment 
Instructions, paragraphs 6.B.(1)(a) of Turbomeca S.A. Alert MSB No. 
A249 72 0100 Version H, dated May 21, 2015 to do the inspections. 
Use Appendix 1 of Turbomeca S.A. Alert MSB No. A249 72 0100 Version 
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 
compressor.
    (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 paragraph (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.

(h) Related Information

    (1) For more information about this AD, contact Wego Wang, 
Aerospace Engineer, Engine Certification Office, FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803; phone: 781-238-7134; fax: 781-238-7199; email: 
wego.wang@faa.gov.
    (2) 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.
    (3) 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.

    Issued in Burlington, Massachusetts, on November 18, 2015.
Colleen M. D'Alessandro,
Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-29886 Filed 11-24-15; 8:45 am]
 BILLING CODE 4910-13-P


