Rule2026-19761
Airworthiness Directives; Hélicoptères Guimbal 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
September 28, 2026
Effective
November 2, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain H[eacute]licopt[egrave]res Guimbal (HG) Model Cabri G2 helicopters. This AD was prompted by a report of a potential malfunction of the helicopter emergency locator transmitter (ELT) and subsequent findings of weak ELT signals on 121.5 MHz and 406 MHz frequencies due to improper antenna installation (location). This AD requires revising the existing rotorcraft flight manual (RFM) for the helicopter. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 91 Issue 186 (Monday, September 28, 2026)</title>
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[Federal Register Volume 91, Number 186 (Monday, September 28, 2026)]
[Rules and Regulations]
[Pages 61118-61120]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-19761]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-4630; Project Identifier MCAI-2025-01824-R;
Amendment 39-23472; AD 2026-19-05]
RIN 2120-AA64
Airworthiness Directives; H[eacute]licopt[egrave]res Guimbal
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
certain H[eacute]licopt[egrave]res Guimbal (HG) Model Cabri G2
helicopters. This AD was prompted by a report of a potential
malfunction of the helicopter emergency locator transmitter (ELT) and
subsequent findings of weak ELT signals on 121.5 MHz and 406 MHz
frequencies due to improper antenna installation (location). This AD
requires revising the existing rotorcraft flight manual (RFM) for the
helicopter. The FAA is issuing this AD to address the unsafe condition
on these products.
DATES: This AD is effective November 2, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of November 2,
2026
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-4630; 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 Guimbal material identified in this AD, contact HG,
1070, rue du Lieutenant Parayre, Ae[acute]rodrome d'Aix-en-Provence,
13290 Les Milles, France; phone: 33-04-42-39-10-88; email:
<a href="/cdn-cgi/l/email-protection#02717772726d7076423e63226a7067643f" http: guimbal.com">guimbal.com</a>">support@<a href="http://guimbal.com">guimbal.com</a></a>; website: <a href="http://guimbal.com">guimbal.com</a>.
<bullet> You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 10101 Hillwood Parkway,
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-2026-4630.
FOR FURTHER INFORMATION CONTACT: David Enns, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316)
946-4147; email: <a href="/cdn-cgi/l/email-protection#492d283f202d672c27273a092f2828672e263f"><span class="__cf_email__" data-cfemail="553134233c317b303b3b26153334347b323a23">[email protected]</span></a>.
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 certain HG Model Cabri
G2 helicopters. The NPRM was published in the Federal Register on May
7, 2026 (91 FR 24752). The NPRM was prompted by European Union Aviation
Safety Agency (EASA) AD 2025-0282, dated December 12, 2025 (EASA AD
2025-0282) (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 that a report of a potential malfunction of the helicopter ELT
was received. Subsequent investigation revealed that due to improper
antenna installation (location), the ELT produced a weaker signal than
expected on 121.5 MHz and 406 MHz frequencies. The MCAI further states
that both HG cockpit ELT antenna configurations are affected.
In the NPRM, the FAA proposed to require revising the existing RFM
for the helicopter. The FAA is issuing 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-2026-4630.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from one anonymous commenter. The
following presents the comment received on the NPRM and the FAA's
response to the comment.
[[Page 61119]]
Request for Mandatory ELT Antenna Modification.
The commenter requested that the FAA revise the NPRM to convert the
optional ELT antenna modification into a requirement and also require a
6-month compliance time associated with the modification. The commenter
stated that the limitation specified in the RFM treats the symptom
instead of the root cause. The commenter also stated that the
underlying issue is that the antenna was improperly located inside the
cockpit, and that the unsafe condition will persist until the
modification is completed. Additionally, the commenter stated the NPRM
omits the deadline of completing the modification within 6 months,
which opens the possibility that an affected aircraft continues to fly
with a degraded ELT.
The FAA disagrees that the ELT antenna modification should be
required. EASA and FAA regulations differ regarding when an ELT is
required. Specifically, under 14 CFR 135.168, FAA regulations require
an ELT for part 135 overwater operations. Once the revision of the RFM
limitations section that is required by this AD has been completed,
overwater operations are prohibited until the modification has been
performed, thereby eliminating the operational context in which a
functional ELT is mandated by FAA regulations. Regarding the
commenter's request for a 6-month compliance time, the FAA notes that
since the modification is optional, no compliance deadline is
necessary. Operators who wish to resume part 135 overwater operations
may complete the modification at their discretion. The FAA did not
change this AD as a result of this comment.
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 the comment received, 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 and the addition of section 6 Final Steps of
Guimbal Mandatory Service Bulletin SB 25-006 B, dated December 12, 2025
(Guimbal SB 25-006 B) to the optional terminating action, 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 Guimbal SB 25-006 B, which specifies procedures
for discarding the VHF2 antenna and associated parts from service (if
installed), modifying the ELT antenna, which includes relocating the
ELT antenna from inside the cockpit to an exterior location, relocating
and installing a new VHF2 antenna (if installed), torquing nuts,
installing cotter pins, trimming the cowlings, routing the ELT antenna
cable, repairing the engine cowl honeycomb, and paint touch-ups.
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 updating the RFM to insert a RFM temporary
revision in the limitation section, whereas this AD does not.
The MCAI requires the modification of the ELT to be completed
within 6 months, whereas this AD does not.
Costs of Compliance
The FAA estimates that this AD affects 70 helicopters of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Revise RFM............................ 1 work-hour x $85 per $0 $85 $5,950
hour = $85.
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The FAA estimates the following costs to do the optional
modification. The agency has no way of determining the number of
helicopters that might need this modification:
Optional Costs
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Action Labor cost Parts cost Cost per product
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Modify ELT antenna..................... 3.5 work-hours x $85 per Up to $1,000 Up to $1,298.
hour = $298.
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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
[[Page 61120]]
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:
2026-19-05 H[eacute]licopt[egrave]res Guimbal: Amendment 39-23472;
Docket No. FAA-2026-4630; Project Identifier MCAI-2025-01824-R.
(a) Effective Date
This airworthiness directive (AD) is effective November 2, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to H[eacute]licopt[egrave]res Guimbal (HG) Model
Cabri G2 helicopters having serial numbers (S/N) 1003 to 1389,
except S/N 1383 and 1388, certificated in any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 2562, Emergency
locator beacon.
(e) Unsafe Condition
This AD was prompted by a report of a potential malfunction of
the helicopter emergency locator transmitter (ELT) and subsequent
findings of weak ELT signals on 121.5 MHz and 406 MHz frequencies
due to improper antenna installation (location). The FAA is issuing
this AD to address the safety risk posed by weak ELT signal
transmissions. The unsafe condition, if not addressed, could impair
the ability to detect a distress signal during a helicopter
emergency, which could delay the arrival of rescue services and
timely medical assistance to injured occupants.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
Within 30 days after the effective date of this AD, revise the
limitations section of the existing rotorcraft flight manual (RFM)
for the helicopter by inserting the following text: ``For Cabri G2
not equipped with the external ELT antenna: Operations conducted
overwater under 14 CFR part 135 are prohibited pursuant to 14 CFR
135.168''.
(1) Inserting a copy of this AD into the limitation section of
the RFM satisfies the requirements of paragraph (g) of this AD.
(2) The owner/operator (pilot) holding at least a private pilot
certificate may revise the existing RFM for the helicopter and must
enter compliance into the helicopter maintenance records in
accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The record must
be maintained as required by 14 CFR 91.417, 121.380, or 135.439.
(h) Optional Terminating Action
(1) For internal ELT antenna helicopters, as a terminating
action, you may modify the ELT antenna and relocate and install a
new VHF2 antenna (if installed) in accordance with section 2 ELT
Antenna Installation through section 4 Engine Cowl Honeycomb Repair
and section 6 Final Steps of Guimbal Mandatory Service Bulletin SB
25-006 B, dated December 12, 2025 (Guimbal SB 25-006 B), except as
provided in paragraphs (h)(1)(i) and (ii) of this AD.
(i) Instead of discarding parts, you must remove those parts
from service.
(ii) Where Guimbal SB 25-006 B uses the term check, this AD
requires doing an inspection.
(2) Upon completion of paragraph (h)(1) of this AD, revise the
RFM by removing the limitation identified in paragraph (g) of this
AD.
(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#0544484a46456364642b626a73"><span class="__cf_email__" data-cfemail="e3a2aeaca0a3858282cd848c95">[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) Additional Information
For more information about this AD, contact David Enns, Aviation
Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY
11590; phone: (316) 946-4147; email: <a href="/cdn-cgi/l/email-protection#b2d6d3c4dbd69cd7dcdcc1f2d4d3d39cd5ddc4"><span class="__cf_email__" data-cfemail="b0d4d1c6d9d49ed5dedec3f0d6d1d19ed7dfc6">[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) Guimbal Mandatory Service Bulletin SB 25-006 B, dated
December 12, 2025.
(ii) [Reserved]
(3) For Guimbal material identified in this AD, contact
H[eacute]licopt[egrave]res Guimbal, 1070, rue du Lieutenant Parayre,
A[eacute]rodrome d'Aix-en-Provence, 13290 Les Milles, France; phone:
+33-4-42-39-10-88; email: <a href="/cdn-cgi/l/email-protection#32414742425d4046720e53125a4057540f" http: guimbal.com">guimbal.com</a>">support@<a href="http://guimbal.com">guimbal.com</a></a>; website: <a href="http://guimbal.com">guimbal.com</a>.
(4) You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 10101 Hillwood Parkway,
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#fe988cd097908d8e9b9d8a979190be909f8c9fd0999188"><span class="__cf_email__" data-cfemail="5f392d7136312c2f3a3c2b3630311f313e2d3e71383029">[email protected]</span></a>.
Issued on September 17, 2026.
Hollister B. Thorson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-19761 Filed 9-25-26; 8:45 am]
BILLING CODE 4910-13-P
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</html>Indexed from Federal Register on September 28, 2026.
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