Proposed Rule2026-01464
Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters
Primary source
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Published
January 26, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 C-2 and MBB-BK 117 D-2 helicopters. This proposed AD was prompted by a determination that a certain part-numbered standard MS18027 type hook may be subject to localized yielding in the mating threads when assembled to higher assembly torques. This proposed AD would require modifying and re-identifying the affected part or replacing the affected part with a serviceable part. This proposed AD would also prohibit installing an affected part on any helicopter unless certain requirements are met. 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 16 (Monday, January 26, 2026)</title>
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[Federal Register Volume 91, Number 16 (Monday, January 26, 2026)]
[Proposed Rules]
[Pages 3092-3094]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-01464]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-0730; Project Identifier MCAI-2025-01416-R]
RIN 2120-AA64
Airworthiness Directives; Airbus Helicopters Deutschland GmbH
(AHD) 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 all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 C-2
and MBB-BK 117 D-2 helicopters. This proposed AD was prompted by a
determination that a certain part-numbered standard MS18027 type hook
may be subject to localized yielding in the mating threads when
assembled to higher assembly torques. This proposed AD would require
modifying and re-identifying the affected part or replacing the
affected part with a serviceable part. This proposed AD would also
prohibit installing an affected part on any helicopter unless certain
requirements are met. The FAA is proposing this AD to address the
unsafe condition on these products.
DATES: The FAA must receive comments on this NPRM by March 12, 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-2026-0730; 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#36777245765357455718534344594657185343"><span class="__cf_email__" data-cfemail="fdbcb98ebd989c8e9cd398888f928d9cd39888">[email protected]</span></a>; website: easa.europa.eu. You may find the EASA
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.
FOR FURTHER INFORMATION CONTACT: Steven Warwick, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (817) 222-5225; email: <a href="/cdn-cgi/l/email-protection#96e5e2f3e0f3f8b8e4b8e1f7e4e1fff5fdd6f0f7f7b8f1f9e0"><span class="__cf_email__" data-cfemail="80f3f4e5f6e5eeaef2aef7e1f2f7e9e3ebc0e6e1e1aee7eff6">[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-2026-0730; Project Identifier
MCAI-2025-01416-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
Steven Warwick, 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 2025-0188, dated September 1, 2025
(EASA AD 2025-0188) (also referred to as the MCAI), to correct an
unsafe condition on AHD Model MBB-BK117 C-2 and MBB-BK117 D-2
helicopters. The MCAI states that the standard MS18027 hook part number
(P/N) 42305-283 installed on the large hook damper assembly P/N 44307-
480, may be subject to localized yielding in the mating threads when
assembled to higher assembly torques.
This condition, if not addressed, could result in failure of the
hook damper assembly, which could result in loss of the hoist load and
injury to persons.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-0730.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA AD 2025-0188, which specifies procedures for
modifying the large hook damper assembly having P/N 44307-480 by
replacing the standard MS18027 hook P/N 42305-283 with D-Lok hook P/N
42315-488 and reidentifying the large hook damper assembly to P/N
44307-480-1.
EASA AD 2025-0188 also specifies procedures for replacing large
hook damper assembly P/N 44307-480 with
[[Page 3093]]
large hook damper assembly P/N 44307-480-1 (modification already
accomplished) as an alternative to the initial modification
requirement. EASA AD 2025-0188 also prohibits installing an affected
large hook damper assembly having P/N 44307-480 on any helicopter
unless certain requirements are met within 12 months of the effective
date of this AD and prohibits installing the affected part 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 civil aviation authority
(CAA) 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 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 accomplishing the actions specified
in EASA AD 2025-0188, described previously, as incorporated by
reference, except for any differences identified as exceptions in the
regulatory text of 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 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 2025-0188 by reference in the FAA final rule. This proposed AD
would, therefore, require compliance with EASA AD 2025-0188 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 2025-0188 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 2025-0188. Material required by
EASA AD 2025-0188 for compliance will be available at <a href="http://regulations.gov">regulations.gov</a>
under Docket No. FAA-2026-0730 after the FAA final rule is published.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 183 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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Modify hook and reidentify large hook 1 work-hour x $85 per $3,545 $3,630 $664,290
damper assembly. hour = $85.
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The FAA estimates the following cost to do any replacement that
would be an alternative method of compliance. The agency has no way of
determining the number of helicopters that might choose this
replacement:
Alternative Method Costs
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Cost per
Action Labor cost Parts cost product
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Replace large hook damper assembly............ 1 work-hours x $85 per hour = $23,867 $23,952
$85.
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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 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 3094]]
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 Deutschland GmbH (AHD): Docket No. FAA-2026-0730;
Project Identifier MCAI-2025-01416-R.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by March 12, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Airbus Helicopters Deutschland GmbH (AHD)
Model MBB-BK 117 C-2 and MBB-BK 117 D-2 helicopters, certificated in
any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 2500, Cabin
Equipment/Furnishings.
(e) Unsafe Condition
This AD was prompted by the determination that the standard
MS18027 type hook may be subject to localized yielding in the mating
threads when assembled to higher assembly torques. The FAA is
issuing this AD to prevent failure of the hook. The unsafe
condition, if not addressed, could result in failure of the large
hook damper assembly, which could result in loss of the hoist load
and injury to persons.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
Except as specified in paragraphs (h) and (i) of this AD: Comply
with all required actions and compliance times specified in, and in
accordance with, European Union Aviation Safety Agency AD 2025-0188,
dated September 1, 2025 (EASA AD 2025-0188).
(h) Exceptions to EASA AD 2025-0188
(1) Where EASA AD 2025-0188 refers to its effective date, this
AD requires using the effective date of this AD.
(2) Where the material referenced in EASA AD 2025-0188 specifies
``discard'', this AD requires replacing that text with ``remove from
service''.
(3) Where the material referenced in EASA AD 2025-0188 specifies
``check'', this AD requires replacing that text with ``inspect''.
(4) Where the material referenced in EASA AD 2025-0188 specifies
``if necessary clean the surface'', this AD requires replacing that
text with ``clean the surface''.
(5) This AD does not adopt the ``Remarks'' section of EASA AD
2025-0188.
(i) No Reporting Requirement
Although the material referenced in EASA AD 2025-0188 specifies
to submit information to the manufacturer, this AD does not require
those actions.
(j) Special Flight Permits
Special flight permits may be issued in accordance with 14 CFR
21.197 and 21.199 to operate the helicopter to a location where the
actions of this AD can be accomplished provided that no external
load is carried.
(k) 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 (l) of
this AD and email to: <a href="/cdn-cgi/l/email-protection#db9a9694989bbdbabaf5bcb4ad"><span class="__cf_email__" data-cfemail="2f6e62606c6f494e4e01484059">[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.
(l) Additional Information
For more information about this AD, contact Steven Warwick,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (817) 222-5225; email:
<a href="/cdn-cgi/l/email-protection#2f5c5b4a594a41015d01584e5d58464c446f494e4e01484059"><span class="__cf_email__" data-cfemail="81f2f5e4f7e4efaff3aff6e0f3f6e8e2eac1e7e0e0afe6eef7">[email protected]</span></a>.
(m) 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 2025-0188,
dated September 1, 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#6d2c291e2d080c1e0c4308181f021d0c430818"><span class="__cf_email__" data-cfemail="2263665162474351430c4757504d52430c4757">[email protected]</span></a>; website: easa.europa.eu. You may
find the EASA material 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#284e5a0641465b584d4b5c4147466846495a49064f475e"><span class="__cf_email__" data-cfemail="c1a7b3efa8afb2b1a4a2b5a8aeaf81afa0b3a0efa6aeb7">[email protected]</span></a>.
Issued on January 22, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-01464 Filed 1-23-26; 8:45 am]
BILLING CODE 4910-13-P
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