Proposed Rule2025-11339
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
June 20, 2025
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to supersede Airworthiness Directive (AD) 2020-24-07, which applies to certain Airbus Helicopters Model AS350B3, EC130B4, and EC130T2 helicopters. AD 2020-24-07 requires modifying and inspecting the pilot's and co-pilot's throttle twist grip (twist grip) for proper operation. Since the FAA issued AD 2020-24-07, Airbus Helicopters developed another modification of the twist grip and additional corrective actions for helicopters already modified. This proposed AD was prompted by reports of the engine remaining in idle when the twist grip was turned from the "IDLE" mode to the "FLIGHT" mode. This proposed AD would retain the actions required by AD 2020-24- 07 and mandate an additional modification, which would constitute terminating action for the repetitive inspections. This proposed AD would also expand the helicopter applicability, propose additional requirements for certain helicopters, and would prohibit installing affected microswitches or an affected twist grip with the affected microswitch. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
<html>
<head>
<title>Federal Register, Volume 90 Issue 117 (Friday, June 20, 2025)</title>
</head>
<body><pre>
[Federal Register Volume 90, Number 117 (Friday, June 20, 2025)]
[Proposed Rules]
[Pages 26225-26228]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-11339]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-1108; Project Identifier MCAI-2025-00428-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 supersede Airworthiness Directive (AD)
2020-24-07, which applies to certain Airbus Helicopters Model AS350B3,
EC130B4, and EC130T2 helicopters. AD 2020-24-07 requires modifying and
inspecting the pilot's and co-pilot's throttle twist grip (twist grip)
for proper operation. Since the FAA issued AD 2020-24-07, Airbus
Helicopters developed another modification of the twist grip and
additional corrective actions for helicopters already modified. This
proposed AD was prompted by reports of the engine remaining in idle
when the twist grip was turned from the ``IDLE'' mode to the ``FLIGHT''
mode. This proposed AD would retain the actions required by AD 2020-24-
07 and mandate an additional modification, which would constitute
terminating action for the repetitive inspections.
[[Page 26226]]
This proposed AD would also expand the helicopter applicability,
propose additional requirements for certain helicopters, and would
prohibit installing affected microswitches or an affected twist grip
with the affected microswitch. The FAA is proposing this AD to address
the unsafe condition on these products.
DATES: The FAA must receive comments on this NPRM by August 4, 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-2025-1108; 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 European Union Aviation Safety Agency (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#59181d2a193c382a38773c2c2b362938773c2c"><span class="__cf_email__" data-cfemail="f7b6b384b792968496d9928285988796d99282">[email protected]</span></a>; 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
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2025-1108.
FOR FURTHER INFORMATION CONTACT: Zain Jamal, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (847)
294-7264; email: <a href="/cdn-cgi/l/email-protection#c9b3a8a0a7e7a3a8a4a8a589afa8a8e7aea6bf"><span class="__cf_email__" data-cfemail="f882999196d69299959994b89e9999d69f978e">[email 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-2025-1108;
Project Identifier MCAI-2025-00428-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 the 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.
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 Zain
Jamal, 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
The FAA issued AD 2020-24-07, Amendment 39-21337 (85 FR 78954,
December 8, 2020) (AD 2020-24-07), for Airbus Helicopters Model AS350B3
helicopters with an ARRIEL 2B1 engine with the two-channel Full
Authority Digital Engine Control (FADEC) and with new twist grip
modification (MOD) 073254 or with an ARRIEL 2D engine installed; Model
EC130B4 helicopters with an ARRIEL 2B1 engine with the two-channel
FADEC and with new twist grip MOD 073773 installed; and Model EC130T2
helicopters with an ARRIEL 2D engine installed. AD 2020-24-07 was
prompted by MCAI originated by EASA, which is the Technical Agent for
the Member States of the European Union. EASA issued EASA AD 2017-0059,
dated April 6, 2017 (EASA AD 2017-0059), to correct an unsafe condition
identified, as the microswitches in the engine ``IDLE''/``FLIGHT''
control system could be affected by the corrosive effects of a salt-
laden atmosphere.
AD 2020-24-07 requires repetitively inspecting the wiring,
performing an insulation test, inspecting the pilot and copilot twist
grip controls, and testing the pilot and copilot twist grip controls
for proper functioning. The FAA issued AD 2020-24-07 to prevent the
failure of one of the microswitches, 53Ka, 53Kb, or 65K, which can
prevent switching from ``IDLE'' mode to ``FLIGHT'' mode during
autorotation training making it impossible to recover from a practice
autorotation and compelling the pilot to continue the autorotation to
the ground. This condition could result in unintended touchdown to the
ground at a flight-idle power setting during a practice autorotation,
damage to the helicopter, and injury to occupants.
Actions Since AD 2020-24-07 Was Issued
Since the FAA issued AD 2020-24-07, EASA superseded AD 2017-0059
and issued EASA AD 2023-0133, dated July 5, 2023 (EASA AD 2023-0133).
EASA AD 2023-0133 states that Airbus Helicopters developed MOD 074782,
introducing a new engine power control assembly with microswitches
53Ka, 53Kb and 65K, and mandating installation of a serviceable
assembly, while prohibiting installation of an affected microswitch on
any helicopter. EASA AD 2023-0133 also expands the applicability to all
serial numbers of Airbus Helicopters Model AS 350 B3, EC 130 B4, and EC
130 T2 helicopters. EASA then superseded AD 2023-0133 and issued EASA
AD 2023-0187, dated October 27, 2023 (EASA AD 2023-0187). EASA AD 2023-
0187 states that errors were found in the modification installation
procedure and requires amending the modification instructions and
additional work for certain helicopters already modified. EASA then
superseded AD 2023-0187 and issued EASA AD 2023-0187R1, dated March 20,
2025 (EASA AD 2023-0187R1) (also referred to as the MCAI), to correct
an unsafe condition for all Airbus Helicopters Model AS 350 B3, EC 130
B4, and EC 130 T2 helicopters. The MCAI states that the salt-laden
atmospheric condition definition should be re-formulated, adjusting to
the less
[[Page 26227]]
restrictive description provided in the applicable aircraft maintenance
manual. The FAA did not issue an AD corresponding to EASA AD 2023-0133
and EASA AD 2023-0187.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-1108.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2023-0187R1, which specifies procedures
for modifying the twist grip operational logic on helicopters with MOD
074263 installed. EASA AD 2023-0187R1 also specifies procedures for
repetitively inspecting for no marks, residue, or corrosion and testing
the ``IDLE'' and ``FLIGHT'' controls on the pilot's and copilot's twist
grips on helicopters with MOD 074699 installed. Additionally, EASA AD
2023-0187R1, specifies procedures for installing MOD 074782 on
helicopters if an affected microswitch is installed, which would
constitute terminating action for the repetitive inspections. For those
helicopters with MOD 074782 installed, EASA AD 2023-0187R1 specifies
accomplishing a one-time inspection of the installation of the
microswitch assembly of the engine power control. EASA AD 2023-0187R1
also prohibits installing a microswitch having a part number (P/N)
T3933-3 or a twist grip containing a microswitch P/N T3933-3 on any
helicopter.
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 design.
Proposed AD Requirements in This NPRM
This proposed AD would retain all the requirements of AD 2020-24-
07. This proposed AD would require installing new microswitches. This
proposed AD would also require accomplishing the actions specified in
the material already described, except for any differences identified
as exceptions in the regulatory text of this proposed AD. See
``Differences Between this Proposed AD and the MCAI'' for a discussion
of the general differences included in this AD.
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 2023-0187R1 by reference in the FAA
final rule. This proposed AD would, therefore, require compliance with
EASA AD 2023-0187R1 in its entirety through that incorporation, except
for any differences identified as exceptions in the regulatory text of
this proposed AD. Material referenced in EASA AD 2023-0187R1 for
compliance will be available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-
2025-1108 after the FAA final rule is published.
Differences Between This Proposed AD and the MCAI
EASA AD 2023-0187R1 specifies the initial inspections within 10
flight hours or 7 days; this AD requires compliance before the next
autorotation training flight, 100 hours time-in-service, or 6 months,
whichever occurs first, as the unsafe condition only occurs when
transitioning the throttle in-flight from flight to idle and back to
flight, such as during a practice autorotation. Additionally, EASA AD
2023-0187R1 specifies installing Airbus Helicopters MOD 074263; this
proposed AD would not require the modification as it would not correct
the unsafe condition.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 856 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 proposed AD.
Inspecting the wiring, performing an insulation test, inspecting
the pilot and copilot twist grip controls, and testing the pilot and
copilot twist grip controls required by MOD 074699 would take about 4
work-hours, for an estimated cost of $340 per helicopter and $291,040
for the U.S. fleet. Installing MOD 074782 would take about 4 work-
hours, for an estimated cost of $340 per helicopter.
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this
proposed AD may be covered under warranty, thereby reducing the cost
impact on affected operators.
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 that the 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:
[[Page 26228]]
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:
0
a. Removing Airworthiness Directive 2020-24-07, Amendment 39-21337 (20
FR 19121, December 8, 2020); and
0
b. Adding the following new airworthiness directive:
Airbus Helicopters: Docket No. FAA-2025-1108; Project Identifier
MCAI-2025-00428-R.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by August 4, 2025.
(b) Affected ADs
This AD replaces AD 2020-24-07, Amendment 39-21337 (20 FR 19121,
December 8, 2020).
(c) Applicability
This AD applies to Airbus Helicopters Model AS350B3, EC130B4,
and EC130T2 helicopters, certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 7600, Engine
Controls.
(e) Unsafe Condition
This AD was prompted by reports of the of the engine remaining
in idle when the throttle twist grip was turned from the ``IDLE''
mode to the ``FLIGHT'' mode. The FAA is issuing this AD to correct
the failure of one of the microswitches, 53Ka, 53Kb, or 65K which
can prevent the pilot from switching from ``IDLE'' mode to
``FLIGHT'' mode during autorotation training making it impossible to
recover from a practice autorotation and compelling the pilot to
continue the autorotation to the ground. This condition could result
in unintended touchdown to the ground at a flight-idle power setting
during a practice autorotation, damage to the helicopter, and injury
to occupants.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
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 2023-0187R1, dated
March 20, 2025 (EASA AD 2023-0187R1).
(h) Exceptions to EASA AD 2023-0187R1
(1) Where EASA AD 2023-0187R1 refers to its effective date,
November 10, 2023 (the effective date of EASA AD 2023-0187, dated
October 27, 2023), or July 19, 2023 (the effective date of EASA AD
2023-0133, dated July 5, 2023), this AD requires using the effective
date of this AD.
(2) Where EASA AD 2023-0187R1 refers to April 13, 2017 (the
effective date of EASA AD 2017-0059, dated April 6, 2017), this AD
requires using January 30, 2019 (the effective date of AD 2018-26-
02, Amendment 39-19532 (83 FR 66093, December 26, 2018)).
(3) Where EASA AD 2023-0187R1 refer to flight hours (FH), this
AD requires using hours time-in-service.
(4) This AD does not adopt paragraphs (1) and (2) of EASA AD
2023-0187R1.
(5) Instead of complying with the compliance times in Table 1 in
paragraph (3) of EASA AD 2023-0187R1, this AD requires the
helicopters identified under the Helicopters in Pre-MOD 074699
Configuration column to accomplish the actions required by paragraph
(3) of EASA AD 2023-0187R1 before the next practice autorotation,
within 100 hours time-in-service, or 6 months after January 12, 2021
(the effective date of AD 2020-24-07), whichever occurs first.
(6) Where Table 2 in paragraph (4), Table 3 in paragraph (7),
and Table 4 in paragraph (9) of EASA AD 2023-0187R1 states ``For
helicopters which operate or have operated in salt-laden atmospheric
conditions,'' this AD requires replacing that text with ``For
helicopters which operate or have operated in salt-laden atmospheric
conditions, or if it cannot be determined if a helicopter has been
operated in salt-laden atmospheric conditions.''
(7) Where paragraph (6) of EASA AD 2023-0187R1 states
``discrepancies are detected,'' this AD requires replacing that text
with ``marks, residue, corrosion, flaky varnish are detected; the
values of the insulation test are less than 10 megaOhms; the
microswitch closes in the ``IDLE'' position and does not open as
soon as the twist grip is turned to the ``FLIGHT'' position; or the
microswitch is open in the ``FLIGHT'' position and does not close as
soon as the twist grip is turned to the ``IDLE'' position''.
(8) Where paragraph (9) of EASA AD 2023-0187R1 states ``any
discrepancy,'' for purposes of this AD, discrepancy is defined as a
nut torque that is outside allowable torque limits, or clearance
between the support plate assembly and the washers that is not
within 01.mm to 0.3 mm.
(9) This AD does not adopt the ``Remarks'' section of EASA AD
2023-0187R1.
(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 and email to: <a href="/cdn-cgi/l/email-protection#d3929e9c9093b5b2b2fdb4bca5"><span class="__cf_email__" data-cfemail="3d7c70727e7d5b5c5c135a524b">[email 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 Zain Jamal, Aviation
Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY
11590; phone: (847) 294-7264; email: <a href="/cdn-cgi/l/email-protection#5a203b333474303b373b361a3c3b3b743d352c"><span class="__cf_email__" data-cfemail="87fde6eee9a9ede6eae6ebc7e1e6e6a9e0e8f1">[email 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 2023-0187R1,
dated March 20, 2025.
(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#28696c5b684d495b49064d5d5a475849064d5d"><span class="__cf_email__" data-cfemail="f1b0b582b194908290df9484839e8190df9484">[email protected]</span></a>; website: easa.europa.eu. You may
find this EASA material on the EASA website at ad.easa.europa.eu.
(4) You may view this material at 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#1a7c68347374696a7f796e7375745a747b687b347d756c"><span class="__cf_email__" data-cfemail="b9dfcb97d0d7cac9dcdacdd0d6d7f9d7d8cbd897ded6cf">[email protected]</span></a>.
Issued on June 16, 2025.
Paul R. Bernado,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-11339 Filed 6-18-25; 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 June 20, 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.