[Federal Register Volume 90, Number 179 (Thursday, September 18, 2025)]
[Rules and Regulations]
[Pages 44962-44964]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-18083]
[[Page 44962]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-1108; Project Identifier MCAI-2025-00428-R;
Amendment 39-23140; AD 2025-18-13]
RIN 2120-AA64
Airworthiness Directives; Airbus Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2020-24-07
for certain Airbus Helicopters Model AS350B3, EC130B4, and EC130T2
helicopters. AD 2020-24-07 required modifying and inspecting the
throttle twist grip (twist grip). Since the FAA issued AD 2020-24-07,
there have been reports of the engine remaining in idle when the twist
grip was turned to the ``FLIGHT'' mode. This AD retains the actions
required by AD 2020-24-07 and adds a modification that constitutes
terminating action for the repetitive inspections. This AD also expands
the helicopter applicability, provides additional requirements for
certain helicopters, and prohibits installing affected microswitches or
an affected twist grip with the affected microswitch. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective October 23, 2025.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of October 23,
2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov 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 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:
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.
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-2025-1108.
FOR FURTHER INFORMATION CONTACT: Zain Jamal, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (847)
294-7264; email: [email protected].
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2020-24-07, Amendment 39-21337 (85 FR
78954, December 8, 2020) (AD 2020-24-07). AD 2020-24-07 applied to
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 required 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.
The NPRM was published in the Federal Register on June 20, 2025 (90
FR 26225). The NPRM was prompted by AD 2023-0133, dated July 5, 2023,
issued by EASA, which is the Technical Agent for the Member States of
the European Union (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 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.
In the NPRM, the FAA proposed to retain the actions required by AD
2020-24-07 and mandate an additional modification, which would
constitute terminating action for the repetitive inspections. In the
NPRM, the FAA also proposed to expand the helicopter applicability,
provide additional requirements for certain helicopters, and prohibit
installation of affected microswitches or an affected twist grip with
the affected microswitch.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2025-1108.
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, considered any comments received, and determined that air safety
requires adopting this AD
[[Page 44963]]
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. None of the changes will
increase the economic burden on any operator.
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 having 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.
Differences Between This AD and the MCAI
The MCAI 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, the MCAI specifies
installing Airbus Helicopters MOD 074263; this AD does not require that
modification as it would not correct the unsafe condition.
Costs of Compliance
The FAA estimates that this AD affects 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 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 takes about 4 work-
hours, for an estimated cost of $340 per helicopter and $291,040 for
the U.S. fleet. Installing MOD 074782 takes 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 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 has determined that 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:
0
a. Removing Airworthiness Directive 2020-24-07, Amendment 39-21337 (85
FR 78954, December 8, 2020); and
0
b. Adding the following new airworthiness directive:
2025-18-13 Airbus Helicopters: Amendment 39-23140; Docket No. FAA-
2025-1108; Project Identifier MCAI-2025-00428-R.
(a) Effective Date
This airworthiness directive (AD) is effective October 23, 2025.
(b) Affected ADs
This AD replaces AD 2020-24-07, Amendment 39-21337 (85 FR 78954,
December 8, 2020) (AD 2020-24-07).
(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).
[[Page 44964]]
(h) Exceptions to EASA AD 2023-0187R1
(1) Where EASA AD 2023-0187R1 refers to the effective dates
identified in paragraphs (h)(1)(i) through (iii) of this AD, this AD
requires using the effective date of this AD.
(i) March 27, 2025 (the effective date of EASA AD 2023-0187R1).
(ii) November 10, 2023 (the effective date of EASA AD 2023-0187,
dated October 27, 2023).
(iii) July 19, 2023 (the effective date of EASA AD 2023-0133,
dated July 5, 2023).
(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 refers 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 state ``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: [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 Zain Jamal, Aviation
Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY
11590; phone: (847) 294-7264; 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 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: [email protected]; 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 www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].
Issued on September 9, 2025.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2025-18083 Filed 9-17-25; 8:45 am]
BILLING CODE 4910-13-P