Proposed Rule2025-06186

Airworthiness Directives; Airbus Helicopters

Primary source

Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.

Published
April 15, 2025

Issuing agencies

Transportation DepartmentFederal Aviation Administration

Abstract

The FAA proposes to adopt 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 proposed AD was prompted by reports of loss of tightening torque between the upper ball bearing end and the main rotor (MR) servo-control. This proposed AD would require inspecting the tightening torque and, depending on the results, taking corrective action. This proposed AD would also require reporting information. These actions are specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference. The FAA is proposing this AD to address the unsafe condition on these products.

Full Text

<html>
<head>
<title>Federal Register, Volume 90 Issue 71 (Tuesday, April 15, 2025)</title>
</head>
<body><pre>
[Federal Register Volume 90, Number 71 (Tuesday, April 15, 2025)]
[Proposed Rules]
[Pages 15667-15670]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-06186]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0617; Project Identifier MCAI-2024-00331-R]
RIN 2120-AA64


Airworthiness Directives; Airbus Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt 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 proposed AD was prompted by 
reports of loss of tightening torque between the upper ball bearing end 
and the main rotor (MR) servo-control. This proposed AD would require 
inspecting the tightening torque and, depending on the results, taking 
corrective action. This proposed AD would also require reporting 
information. These actions are specified in a European Union Aviation 
Safety Agency (EASA) AD, which is proposed for incorporation by 
reference. The FAA is proposing this AD to address the unsafe condition 
on these products.

DATES: The FAA must receive comments on this NPRM by May 30, 2025.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow 
the instructions for submitting comments.
    <bullet> Fax: (202) 493-2251.
    <bullet> 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.
    <bullet> Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> 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 NPRM, the mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
street address for Docket Operations is listed above.
    Material Incorporated by Reference:
    <bullet> For EASA material identified in this proposed AD, contact 
EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 
8999 000; email: <a href="/cdn-cgi/l/email-protection#d79693a497b2b6a4b6f9b2a2a5b8a7b6f9b2a2"><span class="__cf_email__" data-cfemail="7d3c390e3d181c0e1c5318080f120d1c531808">[email&#160;protected]</span></a>; website: easa.europa.eu. You may 
find this material on the EASA website at ad.easa.europa.eu. It is also 
available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2025-0617.
    <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.

FOR FURTHER INFORMATION CONTACT: Peter Schmitt, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: (206) 231-3377; email: <a href="/cdn-cgi/l/email-protection#48382d3c2d3a6629663b2b2025213c3c082e2929662f273e"><span class="__cf_email__" data-cfemail="4333263726316d226d30202b2e2a3737032522226d242c35">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2025-0617; 
Project Identifier MCAI-2024-00331-R'' at the beginning of your 
comments. The most helpful comments reference a specific portion of the 
proposal, explain the reason for any recommended change, and include 
supporting data. The FAA will consider all comments received by the 
closing date and may amend this proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
<a href="http://regulations.gov">regulations.gov</a>, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this NPRM.

[[Page 15668]]

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to Peter 
Schmitt, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590. Any commentary that the FAA receives which is not 
specifically designated as CBI will be placed in the public docket for 
this rulemaking.

Background

    EASA, which is the Technical Agent for the Member States of the 
European Union, has issued EASA AD 2024-0110, dated June 6, 2024 (EASA 
AD 2024-0110) (also referred to as the MCAI), to correct an unsafe 
condition on Airbus Helicopters Model SA 365 N, SA 365 N1, AS 365 N2, 
AS 365 N3, EC 155 B, and EC 155 B1 helicopters. 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. This condition, if not addressed, could result in 
disconnection between the upper ball bearing end and the MR servo-
control, and consequent loss control of the helicopter.
    The FAA is proposing this AD to address the unsafe condition on 
these products. You may examine the MCAI in the AD docket at 
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2025-0617.

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.

FAA's Determination

    These products have been approved by the 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, it has notified the FAA of the unsafe condition described in 
the MCAI referenced above. The FAA is issuing this NPRM after 
determining that the unsafe condition described previously is likely to 
exist or develop on other products of the same type designs.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in EASA AD 2024-0110, described previously, as incorporated by 
reference, except for any differences identified as exceptions in the 
regulatory text of this proposed AD and except as discussed under 
``Differences Between this Proposed AD and the MCAI.''

Explanation of Required Compliance Information

    In the FAA's ongoing efforts to improve the efficiency of the AD 
process, the FAA developed a process to use some civil aviation 
authority (CAA) ADs as the primary source of information for compliance 
with requirements for corresponding FAA ADs. The FAA has been 
coordinating this process with manufacturers and CAAs. As a result, the 
FAA proposes to incorporate EASA AD 2024-0110 by reference in the FAA 
final rule. This proposed AD would, therefore, require compliance with 
EASA AD 2024-0110 in its entirety through that incorporation, except 
for any differences identified as exceptions in the regulatory text of 
this proposed AD. Using common terms that are the same as the heading 
of a particular section in EASA AD 2024-0110 does not mean that 
operators need comply only with that section. For example, where the AD 
requirement refers to ``all required actions and compliance times,'' 
compliance with this AD requirement is not limited to the section 
titled ``Required Action(s) and Compliance Time(s)'' in EASA AD 2024-
0110. Material required by EASA AD 2024-0110 for compliance will be 
available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2025-0617 after the 
FAA final rule is published.

Differences Between This Proposed 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 proposed 
AD. Accordingly, this proposed AD would require those actions be 
accomplished by persons authorized under 14 CFR 43.3.

Interim Action

    The FAA considers this proposed AD 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, if adopted as proposed, would 
affect 63 helicopters of U.S. Registry. Labor rates are estimated at 
$85 per work-hour. Based on these numbers, the FAA estimates the 
following costs to comply with this proposed AD.
    Inspecting the tightening torque of the upper ball bearing end of 
each MR servo control would take 1 work-hour for an 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 would 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 would take .5 work-
hour and parts would 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 would 
take 1 work-hour for an estimated cost of $85 per ball bearing end. 
Depending on the results, replacing a ball bearing end would take 1 
work-hour and parts

[[Page 15669]]

would cost $1,299 for an estimated cost of $1,384 per ball bearing end.
    If required, inspecting the threads of an upper end fitting would 
take 1 work-hour for an estimated cost of $85 per upper-end fitting. 
Depending on the results, replacing an MR servo-control would take 1 
work-hour and parts would 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

    The FAA 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would 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 adding the following new airworthiness 
directive:

Airbus Helicopters: Docket No. FAA-2025-0617; Project Identifier 
MCAI-2024-00331-R.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by May 30, 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.
    (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.

[[Page 15670]]

(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: <a href="/cdn-cgi/l/email-protection#c3828e8c8083a5a2a2eda4acb5"><span class="__cf_email__" data-cfemail="084945474b486e6969266f677e">[email&#160;protected]</span></a>.
    (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

    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: 
<a href="/cdn-cgi/l/email-protection#3e4e5b4a5b4c105f104d5d5653574a4a7e585f5f10595148"><span class="__cf_email__" data-cfemail="f9899c8d9c8bd798d78a9a9194908d8db99f9898d79e968f">[email&#160;protected]</span></a>.

(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: <a href="/cdn-cgi/l/email-protection#4405003704212537256a2131362b34256a2131"><span class="__cf_email__" data-cfemail="6524211625000416044b0010170a15044b0010">[email&#160;protected]</span></a>; 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 <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#076175296e6974776264736e6869476966756629606871"><span class="__cf_email__" data-cfemail="4a2c38642324393a2f293e2325240a242b382b642d253c">[email&#160;protected]</span></a>.

    Issued on April 3, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2025-06186 Filed 4-14-25; 8:45 am]
BILLING CODE 4910-13-P


</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>
Indexed from Federal Register on April 15, 2025.

This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.