Proposed Rule2026-09037
Airworthiness Directives; Hélicoptères Guimbal Helicopters
Primary source
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Published
May 7, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for certain H[eacute]licopt[egrave]res Guimbal (HG) Model Cabri G2 helicopters. This proposed 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 proposed AD would require revising the existing rotorcraft flight manual (RFM) for the helicopter. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 91 Issue 88 (Thursday, May 7, 2026)</title>
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[Federal Register Volume 91, Number 88 (Thursday, May 7, 2026)]
[Proposed Rules]
[Pages 24752-24754]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-09037]
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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]
RIN 2120-AA64
Airworthiness Directives; H[eacute]licopt[egrave]res Guimbal
Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain H[eacute]licopt[egrave]res Guimbal (HG) Model Cabri G2
helicopters. This proposed 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
proposed AD would require revising the existing rotorcraft flight
manual (RFM) for the helicopter. The FAA is proposing this AD to
address the unsafe condition on these products.
DATES: The FAA must receive comments on this NPRM by June 22, 2026.
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-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 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 Guimbal material identified in this proposed AD,
contact HG, 1070, rue du Lieutenant Parayre, A[eacute]rodrome d'Aix-en-
Provence, 13290 Les Milles, France; phone: 33-04-42-39-10-88; email:
<a href="/cdn-cgi/l/email-protection#f0838580809f8284b0cc91d098829596cd" 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.
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#680c091e010c460d06061b280e0909460f071e"><span class="__cf_email__" data-cfemail="2044415649440e454e4e53604641410e474f56">[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 using a method listed
under ADDRESSES. Include ``Docket No. FAA-2026-4630; Project Identifier
MCAI-2025-01824-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.
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 David
Enns, 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
European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Union, has issued
EASA AD 2025-0282, dated December 12, 2025 (EASA AD 2025-0282) (also
referred to as the MCAI), to correct an unsafe condition on certain HG
Model Cabri G2 helicopters. The MCAI states that a
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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.
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.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-4630.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed Guimbal Mandatory Service Bulletin SB 25-006 B,
dated December 12, 2025 (Guimbal SB 25-006 B), which specifies
procedures for removing 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.
FAA's Determination
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 and material 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 require revising the limitations section of
the existing RFM for the helicopter to prohibit overwater operations
conducted under 14 CFR part 135, pursuant to 14 CFR 135.168. The owner/
operator (pilot) holding at least a private pilot certificate may
revise the existing RFM and must enter compliance into the helicopter
maintenance records in accordance with 14 CFR 43.9(a) and
91.417(a)(2)(v). The pilot may perform this action because it only
involves revising the RFM, which could be performed equally well by a
pilot or mechanic. This is an exception to the FAA's standard
maintenance regulations.
Differences Between This Proposed AD and the MCAI
The MCAI specifies updating the RFM to insert a RFM temporary
revision in the limitation section, whereas this proposed AD does not.
The MCAI requires the modification of the ELT to be completed
within 6 months, whereas this proposed AD does not.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 70 helicopters of U.S. registry.
The FAA estimates the following costs to comply with this proposed
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 repair:
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 Up to $1,000........... Up to $1,298.
per 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
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
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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:
H[eacute]licopt[egrave]res Guimbal: Docket No. FAA-2026-4630;
Project Identifier MCAI-2025-01824-R.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by June 22, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to H[eacute]licopt[egrave]res Guimbal (HG) Model
Cabri G2 helicopters having serial number (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) For this AD, 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, 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 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#0d4c40424e4d6b6c6c236a627b"><span class="__cf_email__" data-cfemail="4f0e02000c0f292e2e61282039">[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#f29693849b96dc979c9c81b2949393dc959d84"><span class="__cf_email__" data-cfemail="3e5a5f48575a105b50504d7e585f5f10595148">[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:
33-04-42-39-10-88; email: <a href="/cdn-cgi/l/email-protection#43303633332c3137037f22632b3126257e" 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#ff998dd196918c8f9a9c8b969091bf919e8d9ed1989089"><span class="__cf_email__" data-cfemail="85e3f7abecebf6f5e0e6f1eceaebc5ebe4f7e4abe2eaf3">[email protected]</span></a>.
Issued on May 4, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-09037 Filed 5-6-26; 8:45 am]
BILLING CODE 4910-13-P
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