[Federal Register Volume 90, Number 176 (Monday, September 15, 2025)]
[Proposed Rules]
[Pages 44337-44340]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-17732]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-2543; Project Identifier MCAI-2025-00215-T]
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: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain Airbus Canada Limited Partnership Model BD-500-1A10 and BD-
500-1A11 airplanes. This proposed AD was prompted by the discovery that
titanium fasteners had been incorrectly installed in the butt strap at
the outer wing box lower skin to center wing box interface in lieu of
the correct nickel alloy fasteners. This proposed AD would require the
identification of fasteners installed in the butt strap at the outer
wing box lower skin to center wing box interface, and applicable on-
condition actions. The FAA is proposing this AD to address the unsafe
condition on these products.
DATES: The FAA must receive comments on this proposed AD by October 30,
2025.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: 202-493-2251.
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.
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 regulations.gov under
Docket No. FAA-2025-2543; 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:
For Transport Canada material identified in this proposed
AD, contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada;
telephone 888-663-3639; email [email protected]. You may find this material on the
Transport Canada website at tc.canada.ca/en/aviation. It is also
available at regulations.gov under Docket No. FAA-2025-2543.
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.
FOR FURTHER INFORMATION CONTACT: Aryanna Sanchez, Aviation Safety
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 817-
222-4058; email: [email protected].
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 the ADDRESSES section. Include ``Docket No. FAA-2025-2543;
Project
[[Page 44338]]
Identifier MCAI-2025-00215-T'' 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
regulations.gov, 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
Aryanna Sanchez, Aviation Safety Engineer, FAA, 2200 South 216th St.,
Des Moines, WA 98198; phone: 817-222-4058; email:
[email protected]. Any commentary that the FAA receives which
is not specifically designated as CBI will be placed in the public
docket for this rulemaking.
Background
Transport Canada, which is the aviation authority for Canada, has
issued Transport Canada AD CF-2025-09, dated February 24, 2025
(Transport Canada AD CF-2025-09) (also referred to as the MCAI), to
correct an unsafe condition for certain Airbus Canada Limited
Partnership Model BD-500-1A10 and BD-500-1A11 airplanes. The MCAI
states that titanium fasteners (part number (P/N) B0206003GD) had been
incorrectly installed in the butt strap at the outer wing box lower
skin to center wing box interface in lieu of the correct nickel alloy
fasteners (P/N B0206033GD). The use of titanium fasteners could result
in a reduction in joint strength, and the risk of a fuel leak if the
fastener fails and falls free from the joint. This condition, if not
corrected, could cause damage to and loss of principal structure and
fatigue critical structure.
The FAA is proposing this AD to address the unsafe condition on
these products.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2025-2543.
Material Incorporated by Reference Under 1 CFR Part 51
Transport Canada AD CF-2025-09 specifies procedures for a detailed
inspection to identify the part markings on the head of the fasteners,
and applicable on-condition actions. On-condition actions include
replacing non-serviceable fasteners (those not identified as HST54,
HST154, HST254, B0201074, B0201074 with oversize code X, or B0201074
with oversize code Y). For non-serviceable fasteners, the replacement
includes a detailed inspection to make sure that the fastener heads are
not damaged; the fastener heads are installed within requirements; and
there are no signs of loose fasteners, fasteners that rotated, or
fasteners that moved.
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 referenced above. The FAA is issuing this NPRM
after determining that the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in Transport Canada AD CF-2025-09 described previously, except for any
differences identified as exceptions in the regulatory text of this
proposed 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 civil aviation
authority (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 Transport Canada AD CF-2025-09 by reference
in the FAA final rule. This proposed AD would, therefore, require
compliance with Transport Canada AD CF-2025-09 in its entirety through
that incorporation, except for any differences identified as exceptions
in the regulatory text of this proposed AD. Material required by
Transport Canada AD CF-2025-09 for compliance will be available at
regulations.gov under Docket No. FAA-2025-2543 after the FAA final rule
is published.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 79 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
Estimated Costs for Required Actions
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Labor cost Parts cost Cost per product Cost on U.S. operators
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29 work-hours x $85 per hour = $2,465.............. $0 $2,465 $194,735
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The FAA estimates the following costs to do any necessary on-
condition actions 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 this on-condition action:
[[Page 44339]]
Estimated Costs of On-Condition Actions
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Cost per
Labor cost Parts cost product
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Up to 4 work-hours x $85 per Up to $11,550........... Up to $11,890
hour = $340. (for 11
fasteners).
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The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this proposed AD may be covered under warranty, thereby reducing the
cost impact on affected operators.
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:
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 Canada Limited Partnership (Type Certificate Previously Held
by C Series Aircraft Limited Partnership (CSALP); Bombardier, Inc.):
Docket No. FAA-2025-2543; Project Identifier MCAI-2025-00215-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by October 30, 2025.
(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-2025-09, dated February 24, 2025 (Transport Canada AD
CF-2025-09).
(d) Subject
Air Transport Association (ATA) of America Code 57, Wings.
(e) Unsafe Condition
This AD was prompted by the discovery that titanium fasteners
had been incorrectly installed in the butt strap at the outer wing
box lower skin to center wing box interface in lieu of the correct
nickel alloy fasteners. The FAA is issuing this AD to address the
use of titanium fasteners. The unsafe condition, if not addressed,
could result in a reduction in joint strength, potential damage to
and loss of principal structure and fatigue critical structure, and
the risk of a fuel leak if the fastener fails and falls free from
the joint.
(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-2025-09.
(h) Exceptions to Transport Canada AD CF-2025-09
(1) Where Transport Canada AD CF-2025-09 refers to its effective
date, this AD requires using the effective date of this AD.
(2) Where Transport Canada AD CF-2025-09 refers to ``10000
flight cycles'', this AD requires replacing that text with ``10,000
total flight cycles.''
(i) No Reporting Requirement
Although the material referenced in Transport Canada AD CF-2025-
09 specifies to submit certain information to the manufacturer, this
AD does not include that requirement.
(j) 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 (k) of this AD and email to:
[email protected]. 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
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.
(k) Additional Information
For more information about this AD, contact Aryanna Sanchez,
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA
98198; phone: 817-222-4058; email: [email protected].
(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.
[[Page 44340]]
(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-2025-09, dated February 24, 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 [email protected]. 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 www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].
Issued on September 10, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft
Certification Service.
[FR Doc. 2025-17732 Filed 9-12-25; 8:45 am]
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