Rule2026-05984
Airworthiness Directives; Airbus Canada Limited Partnership (Type Certificate Previously Held by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.) Airplanes
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 27, 2026
Effective
May 1, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500- 1A11 airplanes. This AD was prompted by the discovery on the production line that the electrical system harnesses in lavatory A had reduced bend radii, were not properly secured, and did not meet the requirement for clearance from an oxygen supply line. This AD requires an inspection of the sleeve and electrical harness for chafing damage and incorrect installation, and applicable on-condition actions. 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 59 (Friday, March 27, 2026)</title>
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[Federal Register Volume 91, Number 59 (Friday, March 27, 2026)]
[Rules and Regulations]
[Pages 14755-14758]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-05984]
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Rules and Regulations
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains regulatory documents
having general applicability and legal effect, most of which are keyed
to and codified in the Code of Federal Regulations, which is published
under 50 titles pursuant to 44 U.S.C. 1510.
The Code of Federal Regulations is sold by the Superintendent of Documents.
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Federal Register / Vol. 91, No. 59 / Friday, March 27, 2026 / Rules
and Regulations
[[Page 14755]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-2559; Project Identifier MCAI-2025-00053-T;
Amendment 39-23295; AD 2026-06-06]
RIN 2120-AA64
Airworthiness Directives; Airbus Canada Limited Partnership (Type
Certificate Previously Held by C Series Aircraft Limited Partnership
(CSALP); Bombardier, Inc.) Airplanes
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 Airbus Canada Limited Partnership Model BD-500-1A10 and BD-500-
1A11 airplanes. This AD was prompted by the discovery on the production
line that the electrical system harnesses in lavatory A had reduced
bend radii, were not properly secured, and did not meet the requirement
for clearance from an oxygen supply line. This AD requires an
inspection of the sleeve and electrical harness for chafing damage and
incorrect installation, and applicable on-condition actions. The FAA is
issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective May 1, 2026.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of May 1, 2026.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-2559; 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 Transport Canada material identified in this AD,
contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada;
telephone 888-663-3639; email <a href="/cdn-cgi/l/email-protection#0e5a4d204f677c79617c7a6667606b7d7d4a677c6b6d7a67786b7d234d61607d6769606b7d6a6b606f7867696f6c6762677a6b205a4d4e7a6d20696d206d6f"><span class="__cf_email__" data-cfemail="88dccba6c9e1faffe7fafce0e1e6edfbfbcce1faedebfce1feedfba5cbe7e6fbe1efe6edfbecede6e9fee1efe9eae1e4e1fceda6dccbc8fceba6efeba6ebe9">[email protected]</span></a>. You may find this material on the
Transport Canada website at tc.canada.ca/en/aviation.
<bullet> You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 2200 South 216th St., Des
Moines, WA. For information on the availability of this material at the
FAA, call 206-231-3195. It is also available at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-2559.
FOR FURTHER INFORMATION CONTACT: Yves Petiote, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 202-
975-4867; email: <a href="/cdn-cgi/l/email-protection#ee97988b9dc09e8b9a87819a8bae888f8fc0898198"><span class="__cf_email__" data-cfemail="245d5241570a5441504d4b5041644245450a434b52">[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 Airbus Canada
Limited Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. The
NPRM was published in the Federal Register on September 29, 2025 (90 FR
46533). The NPRM was prompted by AD CF-2025-45, dated August 29, 2025
(Transport Canada AD CF-2025-45) (also referred to as the MCAI), issued
by Transport Canada, which is the aviation authority for Canada. The
MCAI states it was discovered on the production line that electrical
system harnesses in lavatory A had reduced bend radii, were not
properly secured and did not meet the requirement for clearance from an
oxygen supply line. Inadequately secured and installed wire harnesses
could create a chafing condition leading to a source of ignition, and
when combined with an oxygen leak as well as loss of ventilation, may
lead to an uncontrolled fire.
In the NPRM, the FAA proposed to require an inspection of the
sleeve and electrical harness for chafing damage and incorrect
installation, and applicable on-condition actions, as specified in
Transport Canada AD CF-2025-45. 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-2025-2559.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from the Air Line Pilots Association,
International (ALPA) who supported the NPRM without change.
The FAA received additional comments from the Citizens Rulemaking
Alliance. The following presents the comments received on the NPRM and
the FAA's response to each comment.
Request To Justify Forgoing Notice and Comment or Issue an NPRM
The Citizens Rulemaking Alliance requested that the FAA either
provide its justification for finding good cause to bypass notice and
comment procedures, convert this action to an NPRM, or stay the
effective date until 30 days after close of a comment period of at
least 45 days. The commenter asserted the FAA has not adequately
justified use of the good cause exemption to bypass notice and comment
and the 30-day delayed effective date.
The FAA notes the comment was submitted in response to an NPRM for
which the FAA provided a 45-day comment period. This final rule is
effective 35 days after its publication in the Federal Register.
Therefore, no change to this AD is necessary.
Request To Make Incorporation by Reference (IBR) Materials Reasonably
Available
The Citizens Rulemaking Alliance stated that the FAA's current
practices for IBR frequently fail to meet the legal and regulatory
standards for reasonable availability. The commenter called on the FAA
to guarantee that all IBR materials are easily and freely accessible to
the public and affected parties for both commenting and compliance
purposes. The commenter also requested that this access be documented
in the rulemaking record.
The FAA's practices comply with 5 U.S.C. 552(a) of the
Administrative
[[Page 14756]]
Procedure Act and 1 CFR part 51. The FAA makes IBR materials available
in the AD docket when the final rule is published in the Federal
Register, following formal approval of the IBR by the Office of the
Federal Register. Materials may only be posted before the final rule's
publication if they are already publicly available or if there is
written consent from the owner of the IBR material. All relevant
materials incorporated by reference will be accessible in the AD docket
on Regulations.gov, which the public can access without registration or
fees.
The FAA also provides summaries and access details in the preamble
and regulatory text, makes materials available for inspection at FAA
and National Archives and Records Administration (NARA) offices, offers
publisher contact information, and obtains formal IBR approval from the
Office of the Federal Register. These efforts are intended to ensure
that all IBR materials meet the ``reasonably available'' standard
required by 1 CFR part 51. The FAA did not change this AD as a result
of this comment.
Request To Comply With the Paperwork Reduction Act (PRA)
The Citizens Rulemaking Alliance requested that the FAA revise the
AD to comply with the PRA if reporting is required or remove any
reporting provisions until PRA requirements are satisfied. If reporting
is not required, the commenter requested the FAA clarify that in the
AD.
The FAA notes this AD does not require reporting. If an AD were to
require reporting, the preamble of the AD would include a paragraph
titled ``Paperwork Reduction Act'' that would provide the applicable
OMB control number, required PRA statements, and the estimated time to
collect the required information (burden). Any costs associated with
the reporting requirement would be included in the Costs of Compliance
section in the preamble of the AD. Therefore, the FAA did not change
this AD as a result of this comment.
Request To Consider Impact on Small Entities
The commenter requested that the FAA either provide the reasoned
basis for its certification under the Regulatory Flexibility Act (RFA)
that the AD will not have a significant economic impact on a
substantial number of small entities, or prepare an initial regulatory
flexibility analysis if certification cannot be supported.
The FAA disagrees with preparing an initial regulatory flexibility
analysis. The RFA of 1980 (5 U.S.C. 601-612), as amended by the Small
Business Regulatory Enforcement Fairness Act of 1996 (Pub. L. 104-121)
and the Small Business Jobs Act of 2010 (Pub. L. 111-240), requires
Federal agencies to consider the effects of the regulatory action on
small business and other small entities and to minimize any significant
economic impact. The term ``small entities'' comprises small businesses
and not-for-profit organizations that are independently owned and
operated and are not dominant in their fields, and governmental
jurisdictions with populations of less than 50,000.
The FAA identified two air carriers and two corporate trustees that
will be affected by this AD. Based on the Small Business Administration
size standard for air carriers and corporate trustees, all four
entities are large businesses:
Small Business Size Standards 1
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NAICS \2\ Code Description Size standard
------------------------------------------------------------------------
481111..................... Scheduled Passenger Air 1,500 employees.
Transportation.
523991..................... Trust, Fiduciary, and $47.0 million.
Custody Activities.
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\1\ Source: U.S. Small Business Administration, Table of Small Business
Size Standards, <a href="https://www.sba.gov/sites/default/files/2023-06/Table%20of%20Size%20Standards_Effective%20March%2017%2C%202023%20%282%29.pdf">https://www.sba.gov/sites/default/files/2023-06/Table%20of%20Size%20Standards_Effective%20March%2017%2C%202023%20%282%29.pdf</a>.
\2\ North American Industrial Classification System.
If an agency determines that a rulemaking will not result in a
significant economic impact on a substantial number of small entities,
the head of the agency may certify that under section 605(b) of the
RFA. Therefore, as provided in section 605(b) and based on the
foregoing, the head of FAA certifies that this AD will not result in a
significant economic impact on a substantial number of small entities.
The FAA did not change this AD as a result of this comment.
Request To Provide Additional Cost Information
The Citizens Rulemaking Alliance requested that the FAA add to the
AD docket the methodology and assumptions supporting the estimated cost
of the proposed AD and reopen the comment period for public input on
the additional cost information. The commenter stated that the FAA
should also provide the per airplane labor and parts cost, any assumed
downtime or out-of-service impacts, and the aggregate costs for the
U.S. fleet.
The FAA recognizes that, in doing the actions required by an AD,
operators might incur indirect or incidental costs in addition to the
direct costs. The cost analysis in an AD typically describes only the
direct costs of the specific actions required by an AD, which does not
include indirect or incidental costs such as downtime, loss of revenue,
planning, or time necessitated by other administrative actions since
those costs might vary significantly among operators. The number of
work hours necessary to do the required actions of an AD is provided by
the manufacturer. This number represents the time necessary to perform
only the actions actually required by an AD. The cost of parts or
special tools, if necessary, to complete the actions required by an AD
is also provided by the manufacturer. Further, when the FAA is informed
that the manufacturer may cover some or all of the estimated costs of
an AD under warranty, the FAA indicates that in the AD.
In the Cost of Compliance section of the proposed AD, the FAA
disclosed the estimated number of work hours, the number of airplanes
affected on the U.S. registry, estimated parts cost, and the aggregate
costs for the U.S. fleet. Since the FAA has assessed and disclosed the
total known costs of the AD requirements in the Costs of Compliance
section of the proposed AD, and the commenter did not provide
additional cost data for the FAA to consider in its cost analysis, it
is not necessary to reopen the comment period or provide additional
information in the AD docket. 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
[[Page 14757]]
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 Transport Canada AD CF-2025-45, which specifies
procedures for an inspection of the sleeve and electrical harness for
chafing damage and incorrect installation, and applicable on-condition
actions. On-condition actions include repair of damage and installation
of tie-down straps on the electrical harness.
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.
Costs of Compliance
The FAA estimates that this AD affects 83 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
Labor cost Parts cost Cost per product Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
3 work-hour x $85 per hour = $85................... $0 $255 $21,165
----------------------------------------------------------------------------------------------------------------
The FAA estimates the following costs to do any necessary on-
condition action that would be required based on the results of any
required actions. The FAA has no way of determining the number of
aircraft that might need these on-condition actions:
Estimated Costs of On-Condition Installations *
------------------------------------------------------------------------
Labor cost Parts cost Cost per product
------------------------------------------------------------------------
3 work-hours x $85 per hour = $255... $4,935 $5,190
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* The FAA has received no definitive data on which to base the cost
estimates for the on-condition repairs specified in this AD.
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 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:
2026-06-06 Airbus Canada Limited Partnership (Type Certificate
Previously Held by C Series Aircraft Limited Partnership (CSALP);
Bombardier, Inc.): Amendment 39-23295; Docket No. FAA-2025-2559;
Project Identifier MCAI-2025-00053-T.
(a) Effective Date
This airworthiness directive (AD) is effective May 1, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Airbus Canada Limited Partnership (Type
Certificate previously held by C Series Aircraft Limited Partnership
(CSALP); Bombardier, Inc.) Model BD-500-1A10 and BD-500-1A11
airplanes, certificated in any category, as identified in Transport
Canada AD CF-2025-45, dated August 29, 2025 (Transport Canada AD CF-
2025-45).
(d) Subject
Air Transport Association (ATA) of America Code 92, Electrical
system installation.
(e) Unsafe Condition
This AD was prompted by the discovery on the production line
that electrical system harnesses in lavatory A had reduced bend
radii, were not properly secured and did not meet the requirement
for clearance from an oxygen supply line. The FAA is issuing this AD
to address inadequately secured and installed wire harnesses, which
if not addressed, could result in a chafing condition leading to a
source of ignition, and when combined with an oxygen leak as well
[[Page 14758]]
as loss of ventilation, may lead to an uncontrolled fire.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Requirements
Except as specified in paragraph (h) of this AD: Comply with all
required actions and compliance times specified in, and in
accordance with, Transport Canada AD CF-2025-45.
(h) Exceptions to Transport Canada AD CF-2025-45
(1) Where Transport Canada AD CF-2025-45 refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where Transport Canada AD CF-2025-45 refers to January 30,
2025 (the effective date of Transport Canada AD CF-2025-04, dated
January 16, 2025), this AD requires using the effective date of this
AD.
(i) Additional AD Provisions
The following provisions also apply to this AD:
(1) Alternative Methods of Compliance (AMOCs): The Manager, AIR-
520, Continued Operational Safety 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 Continued Operational Safety 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#e2a3afada1a2848383cc858d94"><span class="__cf_email__" data-cfemail="50111d1f13103631317e373f26">[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.
(2) Contacting the Manufacturer: For any requirement in this AD
to obtain instructions from a manufacturer, the instructions must be
accomplished using a method approved by the Manager, AIR-520,
Continued Operational Safety Branch, FAA; or Transport Canada; or
Airbus Canada Limited Partnership's Transport Canada Design Approval
Organization (DAO). If approved by the DAO, the approval must
include the DAO-authorized signature.
(3) Required for Compliance (RC): Except as required by
paragraph (i)(2) of this AD, if any material contains procedures or
tests that are identified as RC, those procedures and tests must be
done to comply with this AD; any procedures or tests that are not
identified as RC are recommended. Those procedures and tests that
are not identified as RC may be deviated from using accepted methods
in accordance with the operator's maintenance or inspection program
without obtaining approval of an AMOC, provided the procedures and
tests identified as RC can be done and the airplane can be put back
in an airworthy condition. Any substitutions or changes to
procedures or tests identified as RC require approval of an AMOC.
(j) Additional Information
For more information about this AD, contact Yves Petiote,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 202-975-4867; email: <a href="/cdn-cgi/l/email-protection#433a3526306d3326372a2c3726032522226d242c35"><span class="__cf_email__" data-cfemail="ceb7b8abbde0beabbaa7a1baab8ea8afafe0a9a1b8">[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 this AD specifies otherwise.
(i) Transport Canada AD CF-2025-45, dated August 29, 2025.
(ii) [Reserved]
(3) For Transport Canada material identified in this AD, contact
Transport Canada, Transport Canada National Aircraft Certification,
159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; telephone 888-
663-3639; email <a href="/cdn-cgi/l/email-protection#bde9fe93fcd4cfcad2cfc9d5d4d3d8cecef9d4cfd8dec9d4cbd8ce90fed2d3ced4dad3d8ced9d8d3dccbd4dadcdfd4d1d4c9d893e9fefdc9de93dade93dedc"><span class="__cf_email__" data-cfemail="76223558371f04011904021e1f18130505321f041315021f0013055b351918051f1118130512131817001f1117141f1a1f0213582235360215581115581517">[email protected]</span></a>. You may find this material on
the Transport Canada website at tc.canada.ca/en/aviation.
(4) You may view this material at the FAA, Airworthiness
Products Section, Operational Safety Branch, 2200 South 216th St.,
Des Moines, WA. For information on the availability of this material
at the FAA, call 206-231-3195.
(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#2046520e494e5350454354494f4e604e4152410e474f56"><span class="__cf_email__" data-cfemail="5e382c7037302d2e3b3d2a3731301e303f2c3f70393128">[email protected]</span></a>.
Issued on March 20, 2026.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2026-05984 Filed 3-26-26; 8:45 am]
BILLING CODE 4910-13-P
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