Rule2026-04921
Airworthiness Directives; Airbus Helicopters Deutschland GmbH (AHD) 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
March 13, 2026
Effective
April 17, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters. This AD was prompted by a report of a main rotor head (MRH) having the same part number (P/N) and serial number (S/N) as another MRH due to incorrect modification instructions where the modified part S/N was not re-identified and the MRH can be operated with the wrong associated log card if accidently interchanged. This AD requires performing a one-time consistency check of the P/N and S/N of the MRH, performing corrective actions if applicable, determining if the MRH has been modified, and re-identifying the modified MRH. This AD also allows replacing the MRH as an optional action and prohibits the installation of an affected MRH on any 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 49 (Friday, March 13, 2026)</title>
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[Federal Register Volume 91, Number 49 (Friday, March 13, 2026)]
[Rules and Regulations]
[Pages 12292-12294]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-04921]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-5393; Project Identifier MCAI-2025-00157-R;
Amendment 39-23277; AD 2026-05-04]
RIN 2120-AA64
Airworthiness Directives; Airbus Helicopters Deutschland GmbH
(AHD) 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 all
Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 A-1, MBB-BK
117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and MBB-BK 117
C-1 helicopters. This AD was prompted by a report of a main rotor head
(MRH) having the same part number (P/N) and serial number (S/N) as
another MRH due to incorrect modification instructions where the
modified part S/N was not re-identified and the MRH can be operated
with the wrong associated log card if accidently interchanged. This AD
requires performing a one-time consistency check of the P/N and S/N of
the MRH, performing corrective actions if applicable, determining if
the MRH has been modified, and re-identifying the modified MRH. This AD
also allows replacing the MRH as an optional action and prohibits the
installation of an affected MRH on any helicopter. The FAA is issuing
this AD to address the unsafe condition on these products.
DATES: This AD is effective April 17, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of April 17,
2026.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-5393; 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 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#9edfdaeddefbffedffb0fbebecf1eeffb0fbeb"><span class="__cf_email__" data-cfemail="a4e5e0d7e4c1c5d7c58ac1d1d6cbd4c58ac1d1">[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, 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
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2025-5393.
FOR FURTHER INFORMATION CONTACT: Promita Dey, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (316)
946-4106; email: <a href="/cdn-cgi/l/email-protection#c1b1b3aeaca8b5a0efa5a4b881a7a0a0efa6aeb7"><span class="__cf_email__" data-cfemail="dcacaeb3b1b5a8bdf2b8b9a59cbabdbdf2bbb3aa">[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 AHD Model MBB-BK 117 A-
1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-1, MBB-BK 117 B-2, and
MBB-BK 117 C-1 helicopters. The NPRM was published in the Federal
Register on December 18, 2025 (90 FR 59078). The NPRM was prompted by
EASA AD 2025-0028, dated February 7, 2025 (EASA AD 2025-0028) (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 an
occurrence was reported of two MRHs having an identical P/N and S/N.
The MCAI further states that a subsequent investigation determined that
the duplicate identification was due to incorrect modification
instructions for the MRH in an Airbus Helicopters service information
notice where the modified part serial number was not re-identified;
this could result in the MRH being operated with the wrong associated
log card if incorrectly interchanged.
In the NPRM, the FAA proposed to require performing a one-time
consistency check of the P/N and S/N of the MRH, performing corrective
actions if applicable, determining if the MRH has been modified, and
re-identifying the modified MRH. The NPRM also proposed to allow
replacing the MRH as an optional action and prohibit the installation
of an affected MRH on any helicopter.
The FAA is issuing this AD to detect and correct the incorrect
identification
[[Page 12293]]
of S/Ns and P/Ns on MRHs which, if not addressed, could result in
operation of an MRH and its critical parts beyond certified limits and
lead to failure of certain parts 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-2025-5393.
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 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 2025-0028, which specifies procedures for
a one-time consistency check of the P/N and S/N of the MRH to verify
against the existing helicopter log card or equivalent record and,
depending on the results, contacting Airbus Helicopters for approved
instructions. EASA AD 2025-0028 also specifies procedures for
performing an additional check of the existing helicopter log card or
equivalent record to determine if the MRH has been modified and
procedures for re-identifying an MRH that has been modified. EASA AD
2025-0028 allows replacing the MRH with a serviceable part in
accordance with the instructions of the applicable Aircraft Maintenance
Manual as an optional action to accomplishing the initial consistency
check and the corrective actions. EASA AD 2025-0028 prohibits
installing an affected MRH 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
Where the MCAI specifies contacting Airbus Helicopters for repair
instructions, this AD requires using a method approved by the FAA,
EASA, or Airbus Helicopters' EASA Design Organization Approval.
Costs of Compliance
The FAA estimates that this AD affects 34 helicopters of U.S.
registry.
The FAA estimates the following costs to comply with this AD.
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Perform consistency check................ 2 work-hours x $85 per hour $0 $170 $5,780
= $170.
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The FAA estimates the following costs to do any actions 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
actions.
On-Condition Costs
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Cost per
Action Labor cost Parts cost product
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Review existing helicopter 1 work-hour x $0 $85
log card or equivalent $85 per hour =
record. $85.
Re-identify MRH.............. 1 work-hour x 0 85
$85 per hour =
$85.
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The FAA has received no definitive data on which to base the cost
estimates for the corrective actions specified in this AD.
Optional Action Costs
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Action Labor cost Parts cost Cost per product
----------------------------------------------------------------------------------------------------------------
Replace MRH...................... 10 work-hours x $85 per Up to $89,000....... Up to $89,850.
hour = $850.
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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
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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 adding the following new airworthiness
directive:
2026-05-04 Airbus Helicopters Deutschland GmbH (AHD): Amendment 39-
23277; Docket No. FAA-2025-5393; Project Identifier MCAI-2025-00157-
R.
(a) Effective Date
This airworthiness directive (AD) is effective April 17, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Airbus Helicopters Deutschland GmbH (AHD)
Model MBB-BK 117 A-1, MBB-BK 117 A-3, MBB-BK 117 A-4, MBB-BK 117 B-
1, MBB-BK 117 B-2, and MBB-BK 117 C-1 helicopters, certificated in
any category.
(d) Subject
Joint Aircraft System Component (JASC) Code 6220, Main Rotor
Head.
(e) Unsafe Condition
This AD was prompted by a report of a main rotor head (MRH)
having the same part number (P/N) and serial number (S/N) as another
MRH due to incorrect modification instructions where the modified
part S/N was not re-identified and the MRH can be operated with the
wrong associated log card if accidently interchanged. The FAA is
issuing this AD to detect and correct the incorrect identification
of S/Ns and P/Ns on MRHs which, if not addressed, could result in
operation of an MRH and its critical parts beyond certified limits
and lead to failure of certain parts and consequent loss of control
of the helicopter.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
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 (EASA) AD
2025-0028, dated February 7, 2025 (EASA AD 2025-0028).
(h) Exceptions to EASA AD 2025-0028
(1) Where EASA AD 2025-0028 refers to its effective date, this
AD requires using the effective date of this AD.
(2) Where EASA AD 2025-0028 requires compliance in terms of
flight hours, this AD requires using hours time-in-service.
(3) Where paragraphs (2) and (4) of EASA AD 2025-0028 specify
discrepancy, for the purposes of this AD, a discrepancy can be
defined as the serial number on the MRH [Main Rotor Head] not
matching the serial number on the helicopters existing log card or
equivalent record.
(4) Where the material referenced in EASA AD 2025-0028 specifies
``check'', this AD requires replacing that text with ``inspect''.
(5) Where EASA AD 2025-0028 and the material referenced in EASA
AD 2025-0028 specifies ``MRH log card'', this AD requires replacing
that text with ``existing helicopter log card or equivalent
record''.
(6) Where EASA AD 2025-0028 or the referenced material specifies
to contact AH [Airbus Helicopters] to obtain approved instructions,
or specifies a part is eligible for installation in accordance with
AH instructions, this AD requires those actions done in accordance
with a method approved by the Manager, International Validation
Branch, FAA; or EASA; or Airbus Helicopters' EASA Design
Organization Approval (DOA). If approved by the DOA, the approval
must include the DOA-authorized signature.
(7) This AD does not adopt the ``Remarks'' section of EASA AD
2025-0028.
(i) No Reporting Requirement
Although the material referenced in EASA AD 2025-0028 specifies
to submit certain information to the manufacturer, this AD does not
require that action.
(j) Alternative Methods of Compliance (AMOCs)
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 responsible Flight
Standards 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#f6b7bbb9b5b6909797d8919980"><span class="__cf_email__" data-cfemail="61202c2e22210700004f060e17">[email protected]</span></a>. Before using any approved AMOC, notify your
appropriate principal inspector, or lacking a principal inspector,
the manager of the responsible Flight Standards Office.
(k) Additional Information
For more information about this AD, contact Promita Dey,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; phone: (913) 563-8269; email:
<a href="/cdn-cgi/l/email-protection#b7c7c5d8dadec3d699d3d2cef7d1d6d699d0d8c1"><span class="__cf_email__" data-cfemail="d5a5a7bab8bca1b4fbb1b0ac95b3b4b4fbb2baa3">[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) AD 2025-0028,
dated February 7, 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#f1b0b582b194908290df9484839e8190df9484"><span class="__cf_email__" data-cfemail="67262314270206140649021215081706490212">[email protected]</span></a>; website: easa.europa.eu. You may
find this 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#f59387db9c9b86859096819c9a9bb59b948794db929a83"><span class="__cf_email__" data-cfemail="593f2b7730372a293c3a2d3036371937382b38773e362f">[email protected]</span></a>.
Issued on February 25, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-04921 Filed 3-12-26; 8:45 am]
BILLING CODE 4910-13-P
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</html>Indexed from Federal Register on March 13, 2026.
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