Rule2026-08324
Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) Helicopters
Primary source
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Published
April 29, 2026
Effective
May 14, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Helicopters Model MBB-BK 117 D-3 helicopters. The FAA previously sent this AD as an emergency AD to all known U.S. owners and operators of these helicopters. This AD was prompted by a report of a crack on the affected part, which was detected after the crew reported increased vibration of the helicopter. This AD requires inspecting the rotor hub-shaft for a crack and depending on the inspection results, replacing any rotor hub-shaft that has any cracks and reporting information after accomplishment of the replacement. This AD also prohibits installing any affected rotor hub- shaft on any helicopter, unless certain requirements are met. 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 82 (Wednesday, April 29, 2026)</title>
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[Federal Register Volume 91, Number 82 (Wednesday, April 29, 2026)]
[Rules and Regulations]
[Pages 22995-22998]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-08324]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2026-3867; Project Identifier MCAI-2026-00403-R;
Amendment 39-23249; AD 2026-08-51]
RIN 2120-AA64
Airworthiness Directives; Airbus Helicopters Deutschland GmbH
(AHD) Helicopters
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
Airbus Helicopters Deutschland GmbH (AHD) Helicopters Model MBB-BK 117
D-3 helicopters. The FAA previously sent this AD as an emergency AD to
all known U.S. owners and operators of these helicopters. This AD was
prompted by a report of a crack on the affected part, which was
detected after the crew reported increased vibration of the helicopter.
This AD requires inspecting the rotor hub-shaft for a crack and
depending on the inspection results, replacing any rotor hub-shaft that
has any cracks and reporting information after accomplishment of the
replacement. This AD also prohibits installing any affected rotor hub-
shaft on any helicopter, unless certain requirements are met. The FAA
is issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective May 14, 2026. Emergency AD 2026-08-51,
issued on April 16, 2026, which contained the requirements of this
amendment, was effective with actual notice.
The Director of the Federal Register approved the incorporation by
reference of a certain publication identified in this AD as of May 14,
2026.
The FAA must receive comments on this AD by June 15, 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
[[Page 22996]]
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-2026-3867; 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
street address for Docket Operations is listed above.
Material Incorporated by Reference:
<bullet> 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: <a href="/cdn-cgi/l/email-protection#edaca99ead888c9e8cc388989f829d8cc38898"><span class="__cf_email__" data-cfemail="3574714675505446541b5040475a45541b5040">[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, 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-2026-3867.
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#b9ddd8cfd0dd97dcd7d7caf9dfd8d897ded6cf"><span class="__cf_email__" data-cfemail="1d797c6b7479337873736e5d7b7c7c337a726b">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written data, views, or arguments
about this final rule. Send your comments using a method listed under
ADDRESSES. Include ``Docket No. FAA-2026-3867; Project Identifier MCAI-
2026-00403-R'' at the beginning of your comments. The most helpful
comments reference a specific portion of the final rule, 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 final rule 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 final rule.
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 AD 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 AD, 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 AD. 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
The FAA issued Emergency AD 2026-08-51, dated April 16, 2026
(Emergency AD 2026-08-51) (also referred to as the emergency AD), to
address an unsafe condition on all AHD Model MBB-BK 117 D-3
helicopters. The FAA sent the emergency AD to all known U.S. owners and
operators of these helicopters. The emergency AD requires inspecting
the rotor hub-shaft for a crack and depending on the inspection
results, replacing any rotor hub-shaft that has any cracks and
reporting information after accomplishment of the replacement. The
emergency AD also prohibits installing any affected rotor hub-shaft on
any helicopter, unless certain requirements are met.
Emergency AD 2026-08-51 was prompted by EASA Emergency AD 2026-
0078-E, dated April 13, 2026 (EASA Emergency AD 2026-0078-E) (also
referred to as the MCAI), issued by EASA, which is the Technical Agent
for the Member States of the European Union, to correct an unsafe
condition on all AHD Model MBB-BK 117 D-3 and D-3m helicopters. The
MCAI states a report of a crack on the affected part was detected after
the crew reported an increased vibration of the helicopter. The MCAI
defines the affected part as a rotor hub-shaft manufacturer part number
D623M1501203 and D623M1501204.
The FAA is issuing this AD to address cracking of the rotor hub-
shaft, which could lead to failure of the main rotor transmission and
consequent loss of control of the helicopter.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2026-3867.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed EASA Emergency AD 2026-0078-E, which specifies
procedures for inspecting the rotor hub-shaft and depending on the
results of the inspection, replacing any rotor hub-shaft that has
cracks or suspicion of cracks, and reporting the results of the
inspection to Airbus Helicopters. EASA Emergency AD 2026-0078-E also
prohibits installing any affected rotor hub-shaft that has not passed
an inspection 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 AD after determining that the unsafe condition described
previously is likely to exist or develop on other products of the same
type design.
AD Requirements
This AD requires accomplishing the actions specified in EASA
Emergency AD 2026-0078-E, described previously, as incorporated by
reference, except for any differences identified as exceptions in the
regulatory text of this AD. See ``Differences Between this AD and the
MCAI,'' for a detailed description of the differences.
Differences Between This AD and the MCAI
The MCAI applies to MBB-BK117 D-3m helicopters, whereas this AD
does not because that model does not have an FAA type certificate.
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
[[Page 22997]]
manufacturers and CAAs. As a result, EASA Emergency AD 2026-0078-E is
incorporated by reference in this AD. This AD requires compliance with
EASA Emergency AD 2026-0078-E in its entirety through that
incorporation, except for any differences identified as exceptions in
the regulatory text of this AD. Using common terms that are the same as
the heading of a particular section in EASA Emergency AD 2026-0078-E
does not mean that operators need comply only with that section. For
example, where EASA Emergency AD 2026-0078-E 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 Emergency AD 2026-0078-E. Material required by EASA
Emergency AD 2026-0078-E for compliance will be available at
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-3867 after this AD is
published.
Justification for Immediate Adoption and Determination of the Effective
Date
Section 553(b) of the Administrative Procedure Act (APA) (5 U.S.C.
551 et seq.) authorizes agencies to dispense with notice and comment
procedures for rules when the agency, for ``good cause,'' finds that
those procedures are ``impracticable, unnecessary, or contrary to the
public interest.'' Under this section, an agency, upon finding good
cause, may issue a final rule without providing notice and seeking
comment prior to issuance. Further, section 553(d) of the APA
authorizes agencies to make rules effective in less than thirty days,
upon a finding of good cause.
An unsafe condition exists that required the immediate adoption of
Emergency AD 2026-08-51, issued on April 16, 2026, to all known U.S.
owners and operators of these helicopters. The FAA found that the risk
to the flying public justified forgoing notice and comment prior to
adoption of this rule because a number of helicopters that have the
affected part installed require immediate action. Accordingly, notice
and opportunity for prior public comment are impracticable and contrary
to the public interest pursuant to 5 U.S.C. 553(b).
In addition, the FAA finds that good cause exists pursuant to 5
U.S.C. 553(d) for making this amendment effective in less than 30 days,
for the same reasons the FAA found good cause to forego notice and
comment.
Regulatory Flexibility Act
The requirements of the Regulatory Flexibility Act (RFA) do not
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt
a rule without prior notice and comment. Because FAA has determined
that it has good cause to adopt this rule without prior notice and
comment, RFA analysis is not required.
Interim Action
The FAA considers that this AD is an interim action. If final
action is later identified, the FAA might consider additional
rulemaking.
Costs of Compliance
The FAA estimates that this AD affects 78 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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Inspect rotor hub-shaft.................. 1 work-hour x $85 per hour $0 $85 $6,630
= $85.
Report inspection results................ 1 work-hour x $85 per hour 0 85 6,630
= $85.
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The FAA estimates the following costs to do any replacements that
would be required based on the results of the inspection. The agency
has no way of determining the number of helicopters that might need
these replacements.
On-Condition Costs
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Action Labor cost Parts cost Cost per product
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Replace rotor hub-shaft...................... 4 work-hours x $85 per hour = $130,468 $130,808
$340.
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Paperwork Reduction Act
A federal agency may not conduct or sponsor, and a person is not
required to respond to, nor shall a person be subject to a penalty for
failure to comply with a collection of information subject to the
requirements of the Paperwork Reduction Act unless that collection of
information displays a currently valid OMB Control Number. The OMB
Control Number for this information collection is 2120-0056. Public
reporting for this collection of information is estimated to be
approximately 1 hour per response, including the time for reviewing
instructions, searching existing data sources, gathering and
maintaining the data needed, and completing and reviewing the
collection of information. All responses to this collection of
information are mandatory. Send comments regarding this burden estimate
or any other aspect of this collection of information, including
suggestions for reducing this burden, to: Information Collection
Clearance Officer, Federal Aviation Administration, 10101 Hillwood
Parkway, Fort Worth, TX 76177-1524.
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.
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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 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, and
(2) Will not affect intrastate aviation in Alaska.
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:
2026-08-51 Airbus Helicopters Deutschland GmbH (AHD): Amendment 39-
23249; Docket No. FAA-2026-3867; Project Identifier MCAI-2026-00403-
R.
(a) Effective Date
The FAA issued Emergency Airworthiness Directive (AD) 2026-08-51
on April 16, 2026 (also referred to as the emergency AD), directly
to affected owners and operators. As a result of such actual notice,
the emergency AD was effective for those owners and operators on the
date it was received. This AD contains the same requirements as the
emergency AD and, for those who did not receive actual notice, is
effective on May 14, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Airbus Helicopters Deutschland GmbH (AHD)
Model MBB-BK 117 D-3 helicopters, certificated in any category.
(d) Subject
Joint Aircraft Service Component (JASC) Code: 6300, Main rotor
drive system.
(e) Unsafe Condition
This AD was prompted by a report of a crack on the affected
part, which was detected after the crew reported increased vibration
of the helicopter. The mandatory continuing airworthiness
information defines the affected part as a rotor hub-shaft
manufacturer part number D623M1501203 and D623M1501204. The FAA is
issuing this AD to address cracking of the rotor hub-shaft, which
could lead to failure of the main rotor transmission and consequent
loss of control of the helicopter.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
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 Emergency AD
2026-0078-E, dated April 13, 2026 (EASA Emergency AD 2026-0078-E).
(h) Exceptions to EASA Emergency AD 2026-0078-E
(1) Where EASA Emergency AD 2026-0078-E refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where EASA Emergency AD 2026-0078-E requires compliance in
terms of flight hours, this AD requires using hours time-in-service.
(3) This AD does not adopt the ``Remarks'' section of EASA
Emergency AD 2026-0078-E.
(i) Special Flight Permits
Special flight permits, as described in 14 CFR 21.197 and
21.199, are not allowed.
(j) 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 (k) of
this AD and email to: <a href="/cdn-cgi/l/email-protection#1e5f53515d5e787f7f30797168"><span class="__cf_email__" data-cfemail="bafbf7f5f9fadcdbdb94ddd5cc">[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.
(k) 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#2d494c5b4449034843435e6d4b4c4c034a425b"><span class="__cf_email__" data-cfemail="1d797c6b7479337873736e5d7b7c7c337a726b">[email protected]</span></a>.
(l) 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) Emergency AD
2026-0078-E, dated April 13, 2026.
(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#9fdedbecdffafeecfeb1faeaedf0effeb1faea"><span class="__cf_email__" data-cfemail="e9a8ad9aa98c889a88c78c9c9b869988c78c9c">[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, 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#d5b3a7fbbcbba6a5b0b6a1bcbabb95bbb4a7b4fbb2baa3"><span class="__cf_email__" data-cfemail="e98f9bc780879a998c8a9d808687a987889b88c78e869f">[email protected]</span></a>.
Issued on April 23, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-08324 Filed 4-28-26; 8:45 am]
BILLING CODE 4910-13-P
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