Back to publication catalog

Published 2021-03-11 · Federal Register document 2021-05046

Airworthiness Directives; Safran Helicopter Engines, S.A. (Type Certificate Previously Held by Turbomeca, S.A.) Turboshaft Engines

Publication summary

The FAA is adopting a new airworthiness directive (AD) for all Safran Helicopter Engines, S.A. Arriel 2C, 2C1, 2S1, and 2S2 model turboshaft engines. This AD was prompted by investigations by the manufacturer following level 1 failures in flight (minor anomalies) and level 2 failures on the ground (minor failures), where cracks were found on the soldered joints of torque conformation boxes. This AD requires performing initial and repetitive inspections of the resistance values of the torque conformation box and, depending on the results of the inspections, replacement of the torque conformation box. The FAA is issuing this AD to address the unsafe condition on these products.

Why this record is shown

Source: Federal Register annual FAA metadata. Acquired 2026-09-03T22:24:08.106391+00:00. The title, summary and date are source facts.

Source revision
federal_register_ad_metadata_2021-9c919420683447c6
Source row
results[66]
Raw source SHA-256
9c919420683447c683ad0c877cb886e341c11862be32b47c536a001b1d76dcb5

Final-rule publication

Recorded publication clauses

AD identifier printed in this edition
2021-05-08
Effective date printed in this edition
2021-04-15
Read 11 complete recorded clauses
Effective Date
(a) Effective Date

    This airworthiness directive (AD) is effective April 15, 2021.

Exact source excerpt. Text positions 10725–10813, end exclusive, in the original decoded publication. SHA-256: 2ad959e731143cb487669a910b3d30978d8f6a38de29d337666de56670464079

Affected ADs
(b) Affected ADs

    None.

Exact source excerpt. Text positions 10813–10842, end exclusive, in the original decoded publication. SHA-256: 871a4afc60ceeae06e8010585055188633d616078500c45937092bfe892239c0

Applicability wording · Applicability
(c) Applicability

    This AD applies to all Safran Helicopter Engines, S.A. (Type 
Certificate previously held by Turbomeca, S.A.) Arriel 2C, 2C1, 2S1, 
and 2S2 model turboshaft engines.

Exact source excerpt. Text positions 10842–11032, end exclusive, in the original decoded publication. SHA-256: 7fcd7f9c726bcaac60235ceaf149499361d6c9cb78319e995327de678f440b8a

Subject
(d) Subject

    Joint Aircraft System Component (JASC) Code 7712, Engine BMEP/
Torque Indicating.

Exact source excerpt. Text positions 11032–11132, end exclusive, in the original decoded publication. SHA-256: 80dd025f2ddbcb1c5916de6aeb05545c18e38a425f86aad425011aa07a4fe84d

Unsafe Condition
(e) Unsafe Condition

    This AD was prompted by investigations by the manufacturer 
following level 1 failures in flight (minor anomalies) and level 2 
failures on the ground (minor failures), where cracks were found on 
the soldered joints of torque conformation boxes. The FAA is issuing 
this AD to prevent failure of the torque conformation box. The 
unsafe condition, if not addressed, could result in failure of the 
engine, in-flight shutdown, and loss of the helicopter.

Exact source excerpt. Text positions 11132–11614, end exclusive, in the original decoded publication. SHA-256: f75fd0f971657c6dab3ddc1cd7178d0db348cee075e4b2728b1e04f7bb3656c2

Compliance
(f) Compliance

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

Exact source excerpt. Text positions 11614–11716, end exclusive, in the original decoded publication. SHA-256: 00fbfa31932483f627d0ce0a11cbd2e35e15d9231842b91ac85623ce533912d3

Required Actions
(g) Required Actions

    (1) For engines with the torque conformation box in pre-
modification TU 34 configuration, installed on Arriel 2C and 2C1 
model turboshaft engines; pre-modification TU 34 or post-
modification TU 188 configuration, installed on Arriel 2S1 model 
turboshaft engines; or post-modification TU 188 configuration, 
installed on Arriel 2S2 model turboshaft engines:
    (i) Within 600 engine hours (EHs) or 180 days after the 
effective date of this AD, whichever occurs first, perform an 
initial inspection of the resistance values of the torque 
conformation box.

    Note 1 to paragraph (g)(1)(i):  You may delay the initial 
inspection by up to 60 EHs to align with other scheduled maintenance 
tasks.

    (ii) Thereafter, perform repetitive inspections of the 
resistance values of the torque conformation box before exceeding 
600 EHs since the last inspection of the resistance values of the 
torque conformation box.
    (2) Use the Accomplishment Instructions, paragraph 2.3.2 or 
4.3.2, of Safran Helicopter Engines Mandatory Service Bulletin No. 
292 72 2868, Version A, dated December 2018, to perform the 
inspections of the resistance values of the torque conformation box 
required by paragraph (g)(1) of this AD.
    (3) If, during any inspection required by paragraph (g)(1) of 
this AD, a non-conforming resistance value is found, before further 
flight, remove the torque conformation box from service and replace 
it with a part eligible for installation.

Exact source excerpt. Text positions 11716–13217, end exclusive, in the original decoded publication. SHA-256: ba8e4b1da3336afaf694319c47354132b7858a2e013a1334b0abaddf39583737

Definition
(h) Definition

    For the purpose of this AD, a ``part eligible for installation'' 
is a zero hour torque conformation box or a torque conformation box 
that has been inspected as required by paragraph (g)(1) of this AD.

Exact source excerpt. Text positions 13217–13441, end exclusive, in the original decoded publication. SHA-256: d87be368c34ec9cc8f4462f93070fd96bd5a37fbb98cede68bae3c8784e0f5bc

Alternative Methods of Compliance (AMOCs)
(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO Branch, FAA, has the authority to approve 
AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
certification office, send it to the attention of the person 
identified in Related Information. You may email your request to: 
[email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

Exact source excerpt. Text positions 13441–14194, end exclusive, in the original decoded publication. SHA-256: bc77289bf111591453ad5b2872177ed6670c6e44d36d73de3629b1e0550462a2

Related Information
(j) Related Information

    (1) For more information about this AD, contact Wego Wang, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7134; fax: (781) 238-7199; 
email: [email protected].
    (2) Refer to European Union Aviation Safety Agency (EASA) AD 
2019-0110, dated May 21, 2019, for more information. You may examine 
the EASA AD in the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-1118.

Exact source excerpt. Text positions 14194–14696, end exclusive, in the original decoded publication. SHA-256: 321bacec4e7d1968a63a71ded2c5354786ca3299fb2659c7be8bc7d55e34b461

Material Incorporated by Reference
(k) 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) Safran Helicopter Engines Mandatory Service Bulletin No. 292 
72 2868, Version A, dated December 2018.
    (ii) [Reserved]
    (3) For Safran Helicopter Engines service information identified 
in this AD, contact Safran Helicopter Engines, S.A., Avenue du 1er 
Mai, Tarnos, France; phone: +33 (0) 5 59 74 45 11.
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 1200 District Avenue, 
Burlington, MA 01803. For information on the availability of this 
material at the FAA, call (781) 238-7759.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

Exact source excerpt. Text positions 14696–15931, end exclusive, in the original decoded publication. SHA-256: f9714ac199e09b22d7032d8a1d7823e5e32ff9014e4877c9f9d1186dd49205a7

No replacement link has been established from this edition. The complete historical rule chain and current legal effect remain unknown.

Find all recorded historical references to AD 2021-05-08 · 0 printed reference observations in this pinned collection.

These are observations from one dated publication. Current legal status is unknown; aircraft applicability, installed configuration, compliance and burden require separate evidence. Missing or unparsed conditions remain unknown.

Why these observations are shown

They were extracted offline from the same immutable official HTML source as the complete recorded text. The dated source wording, original text coordinates and exact quote digests are retained. PDF/text agreement and current regulatory effect have not been qualified.

Observation revision: whole-ad-publication-clause-observations-1.0.1. Text SHA-256: 44197036be14e62db953b6bb95486105e0d19ee0d29e6dc87dbe2935ee37f699. Source manifest: d8b1aadad44148d460dccbba112711cd0a48ffc811793169047a024f9e49fab3.

Official source · 2021-03-11

Publication text

This is the complete recorded text of this dated publication.

Current legal effect is unknown. Aircraft applicability, installed configuration and compliance require separate evidence. PDF/text agreement has not been evaluated.

Read the complete official publication text
[Federal Register Volume 86, Number 46 (Thursday, March 11, 2021)]
[Rules and Regulations]
[Pages 13807-13809]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-05046]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-1118; Project Identifier MCAI-2020-00516-E; 
Amendment 39-21451; AD 2021-05-08]
RIN 2120-AA64


Airworthiness Directives; Safran Helicopter Engines, S.A. (Type 
Certificate Previously Held by Turbomeca, S.A.) Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Safran Helicopter Engines, S.A. Arriel 2C, 2C1, 2S1, and 2S2 model 
turboshaft engines. This AD was prompted by investigations by the 
manufacturer following level 1 failures in flight (minor anomalies) and 
level 2 failures on the ground (minor failures), where cracks were 
found on the soldered joints of torque conformation boxes. This AD 
requires performing initial and repetitive inspections of the 
resistance values of the torque conformation box and, depending on the 
results of the inspections, replacement of the torque conformation box. 
The FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective April 15, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 15, 
2021.

ADDRESSES: For service information identified in this final rule, 
contact Safran Helicopter Engines, S.A., Avenue du 1er Mai, Tarnos, 
France; phone: +33 (0) 5 59 74 45 11. You may view this service 
information at the FAA, Airworthiness Products Section, Operational 
Safety Branch, 1200 District Avenue, Burlington, MA 01803. For 
information on the availability of this material at the FAA, call (781) 
238-7759. It is also available at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-1118.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-1118; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains this final rule, the 
mandatory continuing airworthiness information (MCAI), any comments 
received, and other information. The address for Docket Operations is 
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 INFORMATION CONTACT: Wego Wang, Aviation Safety Engineer, 
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 
(781) 238-7134; fax: (781) 238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all Safran Helicopter 
Engines, S.A. Arriel 2C, 2C1, 2S1, and 2S2 model turboshaft engines. 
The NPRM published in the Federal Register on

[[Page 13808]]

December 10, 2020 (85 FR 79438). The NPRM was prompted by 
investigations by the manufacturer following level 1 failures in flight 
(minor anomalies) and level 2 failures on the ground (minor failures), 
where cracks were found on the soldered joints of torque conformation 
boxes. In the NPRM, the FAA proposed to require performing initial and 
repetitive inspections of the resistance values of the torque 
conformation box and, depending on the results of the inspections, 
replacement of the torque conformation box. The FAA is issuing this AD 
to address the unsafe condition on these products.
    The European Union Aviation Safety Agency (EASA), which is the 
Technical Agent for the Member States of the European Community, has 
issued EASA AD 2019-0110, dated May 21, 2019 (referred to after this as 
``the MCAI''), to address the unsafe condition on these products. The 
MCAI states:

    It was reported that, during investigations following level 1 
failures in flight (minor anomalies) and level 2 failures on the 
ground (minor failures), cracks were found on the soldered joints of 
certain torque conformation boxes. Although no events in operation 
were reported of One Engine Inoperative (OEI) ratings maximum power 
unavailability, the failure mode analysis for these boxes 
demonstrated that such event could not be excluded. This condition, 
if not detected and corrected, could lead to engine in-flight shut-
down, possibly resulting in reduced control of the helicopter.
    To address this potential unsafe condition, SAFRAN Helicopter 
Engines issued the SB [Service Bulletin], to provide instructions 
for repetitive checks of the box resistance values. For the reasons 
described above, this [EASA] AD requires repetitive checks of the 
affected part and, depending on findings, replacement of the 
affected part with a serviceable part.

    You may obtain further information by examining the MCAI in the AD 
docket at https://www.regulations.gov by searching for and locating 
Docket No. FAA-2020-1118.

Discussion of Final Airworthiness Directive Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    The FAA reviewed the relevant data and determined that air safety 
requires adopting this AD as proposed. Accordingly, the FAA is issuing 
this AD to address the unsafe condition on these products. This AD is 
adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Safran Helicopter Engines Mandatory Service 
Bulletin (MSB) No. 292 72 2868, Version A, dated December 2018. This 
service information specifies procedures for performing an inspection 
of the resistance values of the torque conformation box. 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 ADDRESSES.

Costs of Compliance

    The FAA estimates that this AD affects 257 engines installed on 
helicopters of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspect resistance values of the        1 work-hour x $85 per                 $0             $85         $21,845
 torque conformation box.                hour = $85.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacement that would be required based on the results of the 
inspections. The agency has no way of determining the number of 
aircraft that might need this replacement:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace the torque conformation box...........  1 work-hour x $85 per hour = $85          $1,841          $1,926
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this AD 
may be covered under warranty, thereby reducing the cost impact on 
affected individuals.

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.
    The FAA is 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

    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.
    For the reasons discussed above, I certify this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and

[[Page 13809]]

    (3) 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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 adding the following new airworthiness 
directive:

2021-05-08 Safran Helicopter Engines, S.A. (Type Certificate 
previously held by Turbomeca, S.A.): Amendment 39-21451; Docket No. 
FAA-2020-1118; Project Identifier MCAI-2020-00516-E.

(a) Effective Date

    This airworthiness directive (AD) is effective April 15, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Safran Helicopter Engines, S.A. (Type 
Certificate previously held by Turbomeca, S.A.) Arriel 2C, 2C1, 2S1, 
and 2S2 model turboshaft engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7712, Engine BMEP/
Torque Indicating.

(e) Unsafe Condition

    This AD was prompted by investigations by the manufacturer 
following level 1 failures in flight (minor anomalies) and level 2 
failures on the ground (minor failures), where cracks were found on 
the soldered joints of torque conformation boxes. The FAA is issuing 
this AD to prevent failure of the torque conformation box. The 
unsafe condition, if not addressed, could result in failure of the 
engine, in-flight shutdown, and loss of the helicopter.

(f) Compliance

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

(g) Required Actions

    (1) For engines with the torque conformation box in pre-
modification TU 34 configuration, installed on Arriel 2C and 2C1 
model turboshaft engines; pre-modification TU 34 or post-
modification TU 188 configuration, installed on Arriel 2S1 model 
turboshaft engines; or post-modification TU 188 configuration, 
installed on Arriel 2S2 model turboshaft engines:
    (i) Within 600 engine hours (EHs) or 180 days after the 
effective date of this AD, whichever occurs first, perform an 
initial inspection of the resistance values of the torque 
conformation box.

    Note 1 to paragraph (g)(1)(i):  You may delay the initial 
inspection by up to 60 EHs to align with other scheduled maintenance 
tasks.

    (ii) Thereafter, perform repetitive inspections of the 
resistance values of the torque conformation box before exceeding 
600 EHs since the last inspection of the resistance values of the 
torque conformation box.
    (2) Use the Accomplishment Instructions, paragraph 2.3.2 or 
4.3.2, of Safran Helicopter Engines Mandatory Service Bulletin No. 
292 72 2868, Version A, dated December 2018, to perform the 
inspections of the resistance values of the torque conformation box 
required by paragraph (g)(1) of this AD.
    (3) If, during any inspection required by paragraph (g)(1) of 
this AD, a non-conforming resistance value is found, before further 
flight, remove the torque conformation box from service and replace 
it with a part eligible for installation.

(h) Definition

    For the purpose of this AD, a ``part eligible for installation'' 
is a zero hour torque conformation box or a torque conformation box 
that has been inspected as required by paragraph (g)(1) of this AD.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO Branch, FAA, has the authority to approve 
AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
certification office, send it to the attention of the person 
identified in Related Information. You may email your request to: 
[email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(j) Related Information

    (1) For more information about this AD, contact Wego Wang, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7134; fax: (781) 238-7199; 
email: [email protected].
    (2) Refer to European Union Aviation Safety Agency (EASA) AD 
2019-0110, dated May 21, 2019, for more information. You may examine 
the EASA AD in the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-1118.

(k) 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) Safran Helicopter Engines Mandatory Service Bulletin No. 292 
72 2868, Version A, dated December 2018.
    (ii) [Reserved]
    (3) For Safran Helicopter Engines service information identified 
in this AD, contact Safran Helicopter Engines, S.A., Avenue du 1er 
Mai, Tarnos, France; phone: +33 (0) 5 59 74 45 11.
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 1200 District Avenue, 
Burlington, MA 01803. For information on the availability of this 
material at the FAA, call (781) 238-7759.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on February 19, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-05046 Filed 3-10-21; 8:45 am]
BILLING CODE 4910-13-P


Why this text is shown

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T01:53:09.240004+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256
3d7e0c408d402baad54a37ca25f2fb15a3905c025186ba0daf03ea6e45576375
Text SHA-256
44197036be14e62db953b6bb95486105e0d19ee0d29e6dc87dbe2935ee37f699

Return to the full metadata catalog · Search complete publication text · Explore retained publication text and evidence

Coverage and limits

These are dated publication metadata, recorded clauses and literal source observations. Word, model-label, header and reference matches do not establish current legal effect, manufacturer/model identity, aircraft applicability, installed configuration or compliance.

The collection uses 33 explicit annual source snapshots. Source captures and operative-text qualifications have separate states. Missing information remains unknown.