[Federal Register Volume 91, Number 123 (Monday, June 29, 2026)]
[Proposed Rules]
[Pages 39037-39040]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-13023]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2026-4669; Project Identifier MCAI-2025-00426-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 AD was prompted by the discovery of a low 
clearance condition between a hydraulic motor pump harness and the 
airplane structure at the aft fuselage between certain frames, which 
was found during final airplane assembly. This proposed AD would 
require modification of the harness installation. 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 August 13, 
2026.

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.

[[Page 39038]]

    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2026-4669; 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-2026-4669.
     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: Frank Carreras, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3539; 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-2026-4669; 
Project Identifier MCAI-2025-00426-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 Frank 
Carreras, Aviation Safety Engineer, FAA, 2200 South 216th St., Des 
Moines, WA 98198; phone: 206-231-3539; 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-2025-18, dated March 21, 2025 (Transport 
Canada AD CF-2025-18) (also referred to as the MCAI), to correct an 
unsafe condition for certain Airbus Canada Limited Partnership (ACLP) 
Model BD-500-1A10 and BD-500-1A11 airplanes. The MCAI states that 
during final assembly of an airplane, ACLP discovered a low clearance 
condition between a hydraulic motor pump harness and the airplane 
structure at the aft fuselage between frame (FR) 80 and FR 81. Harness 
chafing in this area can generate an ignition source. This condition, 
if not corrected, could lead to an uncontained fire when in the 
presence of flammable fluids.
    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-2026-4669.

Material Incorporated by Reference Under 1 CFR Part 51

    Transport Canada AD CF-2025-18 specifies procedures for modifying 
the harness installation of the hydraulic motor pump by adding a clamp 
support on the bracket for the harness installation, between FR 80 and 
FR 81 of the aft fuselage.
    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. 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-2025-18 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-2025-18 by reference 
in the FAA final rule. This proposed AD would, therefore, require 
compliance with Transport Canada AD CF-2025-18 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-2025-18 for compliance will be available at 
regulations.gov under Docket No. FAA-2026-4669 after the FAA final rule 
is published.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 101 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

[[Page 39039]]



                                      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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1 work-hour x $85 per hour = $85....................          $27                 $112                   $11,312
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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:

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-2026-4669; Project Identifier MCAI-2025-00426-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by August 13, 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-2025-18, dated March 21, 2025 (Transport Canada AD CF-
2025-18).

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by the discovery during final assembly of a 
low clearance condition between a hydraulic motor pump harness and 
the airplane structure at the aft fuselage between frame (FR) 80 and 
FR 81. The FAA is proposing this AD to prevent harness chafing in 
this area, which can generate an ignition source. The unsafe 
condition, if not corrected, could lead to an uncontained fire when 
in the presence of flammable fluids.

(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-2025-18.

(h) Exceptions to Transport Canada AD CF-2025-18

    (1) Where Transport Canada AD CF-2025-18 refers to its effective 
date, this AD requires using the effective date of this AD.
    (2) Where Transport Canada AD CF-2025-18 refers to hours air 
time, this AD requires using flight hours.

(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: 
[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 
Airbus Canada Limited Partnership's Transport Canada Design Approval 
Organization (DAO). If approved by the DAO, the approval must 
include the DAO-authorized signature.

(j) Additional Information

    For more information about this AD, contact Frank Carreras, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3539; email: [email protected].

(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-2025-18, dated March 21, 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.

[[Page 39040]]

    (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 June 24, 2026.
Brian Knaup,
Acting Deputy Director, Integrated Certificate Management Division, 
Aircraft Certification Service.
[FR Doc. 2026-13023 Filed 6-26-26; 8:45 am]
BILLING CODE 4910-13-P