Airworthiness Directives; Airbus Helicopters

[Federal Register Volume 90, Number 130 (Thursday, July 10, 2025)]
[Rules and Regulations]
[Pages 30581-30583]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-12873]



[[Page 30581]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0617; Project Identifier MCAI-2024-00331-R; 
Amendment 39-23075; AD 2025-13-09]
RIN 2120-AA64


Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Airbus Helicopters Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-
365N, and SA-365N1 helicopters. This AD was prompted by reports of loss 
of tightening torque between the upper ball bearing end and the main 
rotor (MR) servo-control. This AD requires inspecting the tightening 
torque and, depending on the results, taking corrective action. This AD 
also requires reporting information. The FAA is issuing this AD to 
address the unsafe condition on these products.

DATES: This AD is effective August 14, 2025.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of August 14, 
2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2025-0617; 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.
    Material Incorporated by Reference:
    <bullet> For European Union Aviation Safety Agency (EASA) material 
identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 
Cologne, Germany; phone: +49 221 8999 000; email: [email protected]; 
website: easa.europa.eu. You may find this material on the EASA website 
at ad.easa.europa.eu.
    <bullet> You may view this material at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-
321, Fort Worth, TX 76177. For information on the availability of this 
material at the FAA, call (817) 222-5110. It is also available at 
regulations.gov under Docket No. FAA-2025-0617.

FOR FURTHER INFORMATION CONTACT: Peter Schmitt, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: (206) 231-3377; 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 Airbus Helicopters 
Model AS-365N2, AS 365 N3, EC 155B, EC155B1, SA-365N, and SA-365N1 
helicopters. The NPRM was published in the Federal Register on April 
15, 2025 (90 FR 15667). The NPRM was prompted by EASA AD 2024-0110, 
dated June 6, 2024 (EASA AD 2024-0110) (also referred to as the MCAI), 
issued by EASA, which is the Technical Agent for the Member States of 
the European Union. The MCAI states two occurrences were reported of 
loss of tightening torque between the upper ball bearing end and the MR 
servo-control, which in one occurrence, led to the disconnection of 
these two parts. The MCAI further states that the investigation is 
still on-going to determine the root cause. EASA considers this MCAI an 
interim action and further action may follow.
    In the NPRM, the FAA proposed to require inspecting the tightening 
torque and, depending on the results, taking corrective action. 
Additionally, in the NPRM the FAA proposed to require reporting certain 
information.
    The FAA is issuing this AD to detect loss of tightening torque. The 
unsafe condition, if not addressed, could result in disconnection 
between the upper ball bearing end and the MR servo-control, and 
consequent loss of control of the helicopter.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2025-0617.

Discussion of Final Airworthiness Directive

Comments

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

Conclusion

    These products have been approved by the civil aviation authority 
of another country and are approved for operation in the United States. 
Pursuant to the FAA's bilateral agreement with this State of Design 
Authority, that authority has notified the FAA of the unsafe condition 
described in the MCAI referenced above. 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. Except for minor editorial changes, this 
AD is adopted as proposed in the NPRM.

Material Incorporated by Reference Under 1 CFR Part 51

    EASA AD 2024-0110 requires a one-time check of the torque on each 
nut connecting the upper ball bearing end to all three MR servo-
controls and, depending on the results, taking corrective actions, 
which include applying torque, lockwire, and sealing compound to the 
upper ball bearing end of the MR servo-control, inspecting the ball 
bearing end of the MR-servo control, replacing a ball bearing end, 
inspecting the upper end fitting of the MR-servo control, and replacing 
the MR servo-control. EASA AD 2024-0110 also requires reporting the 
inspection results (including no findings) to AH [Airbus Helicopters].
    This material 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.

Differences Between This AD and the MCAI

    The MCAI, as well as the material referenced in the MCAI, refer to 
the ``torque inspection'' as a ``check.'' In an FAA AD, a ``check'' may 
be done by the owner/operator (pilot) holding at least a private pilot 
certificate provided certain criteria are met. The authorization for a 
``check'' in an FAA AD is an exception to the FAA's standard 
maintenance regulations and the criteria is not met in this AD. 
Accordingly, this AD requires those actions be accomplished by persons 
authorized under 14 CFR 43.3.

Interim Action

    The FAA considers that this AD is an interim action. If final 
action is later identified, the FAA might consider further rulemaking 
then.

Costs of Compliance

    The FAA estimates that this AD affects 63 helicopters of U.S. 
registry. Labor costs are estimated at $85 per hour. Based on these 
numbers, the FAA estimates the following costs to comply with this AD.
    Inspecting the tightening torque of the upper ball bearing end of 
each MR servo control will take 1 work-hour for an

[[Page 30582]]

estimated cost of $255 per helicopter (three MR servo-controls per 
helicopter) and $16,065 for the U.S. fleet.
    Reporting the results of the inspection will take 1 work-hour for 
an estimated cost of $85 per helicopter and $5,355 for the U.S. fleet.
    If required, applying torque, lock-wire, and sealing compound to 
the upper ball bearing end of each MR servo-control will take .5 work-
hour and parts will cost a nominal amount for an estimated cost of 
$127.50 per helicopter (for up to three MR servo-controls per 
helicopter).
    If required, inspecting the threads of a ball bearing end will take 
1 work-hour for an estimated cost of $85 per ball bearing end. 
Depending on the results, replacing a ball bearing end will take 1 
work-hour and parts will cost $1,299 for an estimated cost of $1,384 
per ball bearing end.
    If required, inspecting the threads of an upper end fitting will 
take 1 work-hour for an estimated cost of $85 per upper-end fitting. 
Depending on the results, replacing an MR servo-control will take 1 
work-hour and parts will cost $41,039 for an estimated cost of $41,124 
per MR servo-control.

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a currently valid OMB Control Number. The OMB 
Control Number for this information collection is 2120-0056. Public 
reporting for this collection of information is estimated to take 
approximately 1 hour per response, including the time for reviewing 
instructions, searching existing data sources, gathering and 
maintaining the data needed, and completing and reviewing the 
collection of information. All responses to this collection of 
information are mandatory. Send comments regarding this burden estimate 
or any other aspect of this collection of information, including 
suggestions for reducing this burden, to: Information Collection 
Clearance Officer, Federal Aviation Administration, 10101 Hillwood 
Parkway, Fort Worth, TX 76177-1524.

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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (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:

2025-13-09 Airbus Helicopters: Amendment 39-23075; Docket No. FAA-
2025-0617; Project Identifier MCAI-2024-00331-R.

(a) Effective Date

    This airworthiness directive (AD) is effective August 14, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Airbus Helicopters Model AS-365N2, AS 365 N3, 
EC 155B, EC155B1, SA-365N, and SA-365N1 helicopters, certificated in 
any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 6710, Main rotor 
control.

(e) Unsafe Condition

    This AD was prompted by reports of two occurrences of loss of 
tightening torque between the upper ball bearing end and the main 
rotor (MR) servo-control. The FAA is issuing this AD to detect loss 
of tightening torque. The unsafe condition, if not addressed, could 
result in disconnection between the upper ball bearing end and the 
MR servo-control, and consequent loss of control of the helicopter.

(f) Compliance

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

(g) Required Actions

    Except as specified in paragraph (h) of this AD: Comply with all 
required actions and compliance times specified in, and in 
accordance with, European Union Aviation Safety Agency AD 2024-0110, 
dated June 6, 2024 (EASA AD 2024-0110).

(h) Exceptions to EASA AD 2024-0110

    (1) Where EASA AD 2024-0110 defines ``the ASB'', this AD 
requires replacing that definition with ``Airbus Helicopters Alert 
Service Bulletin (ASB) AS365-67-30-0001, AS366-67-30-0001, or EC155-
67-30-0001, each Issue 2 and dated May 15, 2024, as applicable for 
the model helicopter. For compliance with this AD, Model SA-365N and 
SA-365N1 helicopters are to use ASB AS365-67-30-0001, Issue 2, dated 
May 15, 2024''.
    (2) Where EASA AD 2024-0110 requires compliance in terms of 
flight hours, this AD requires using hours time-in-service.
    (3) Where EASA AD 2024-0110 refers to its effective date, this 
AD requires using the effective date of this AD.
    (4) Where paragraph (1) of EASA AD 2024-0110 and the material 
referenced in EASA AD 2024-0110 specify ``check'', this AD requires 
replacing that text with ``inspect'' or ``inspection'' as 
applicable.
    (5) Where the material referenced in EASA AD 2024-0110 specifies 
discarding parts, this AD requires removing those parts from 
service.
    (6) Where the material referenced in EASA AD 2024-0110 specifies 
hard point, for this AD a hard point may be indicated by resistance, 
ratcheting, blocking, or difficulty when turning the ball bearing 
end into the upper end fitting of the MR servo-control by hand.

[[Page 30583]]

    (7) Where paragraph (3) of EASA AD 2024-0110 specifies reporting 
inspection results (including no findings) to AH [Airbus 
Helicopters] within 7 days after the inspection required by 
paragraph (1) of EASA AD 2024-0110, this AD requires reporting that 
information at the applicable time in paragraph (h)(7)(i) or (ii) of 
this AD.
    (i) If the inspection was done on or after the effective date of 
this AD: Submit the report within 30 days after the inspection 
required by paragraph (1) of EASA AD 2024-0110.
    (ii) If the inspection was done before the effective date of 
this AD: Submit the report within 30 days after the effective date 
of this AD.
    (8) This AD does not adopt the ``Remarks'' section of EASA AD 
2024-0110.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, International Validation 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 International Validation Branch, send 
it to the attention of the person identified in paragraph (j) of 
this AD. Information may be emailed 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) Additional Information

    For more information about this AD, contact Peter Schmitt, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (206) 231-3377; email: 
[email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the material listed in this paragraph 
under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (i) European Union Aviation Safety Agency (EASA) AD 2024-0110, 
dated June 6, 2024.
    (ii) [Reserved]
    (3) For EASA material identified in this AD, contact EASA, 
Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 
000; email: [email protected]; website: easa.europa.eu. You may 
find this EASA AD on the EASA website at ad.easa.europa.eu.
    (4) You may view this material at the FAA, Office of the 
Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-
321, Fort Worth, TX 76177. For information on the availability of 
this material at the FAA, call (817) 222-5110.
    (5) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on July 1, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-12873 Filed 7-9-25; 8:45 am]
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