Airworthiness Directives; Bombardier, Inc., Airplanes

Issuing agencies

Abstract

The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model CL-600-2B16 (604 Variants) airplanes. This proposed AD was prompted by reports of cracks being found on the lower wing plank at the rear spar wing station (WS) 59 to WS 65 web and/or flange. This proposed AD would require inspecting the lower wing plank rear spar web and lower flange, the forward surface of the pressure bulkhead frame under the stiffeners, and the vertical stabilizer front spar to frame attachment fitting lower legs for cracks, and repair or rectification if applicable. The FAA is proposing this AD to address the unsafe condition on these products.

Full Text

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<title>Federal Register, Volume 91 Issue 216 (Tuesday, November 10, 2026)</title>
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[Federal Register Volume 91, Number 216 (Tuesday, November 10, 2026)]
[Proposed Rules]
[Pages 72467-72470]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-22899]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2026-13808; Project Identifier MCAI-2024-00785-T]
RIN 2120-AA64


Airworthiness Directives; Bombardier, Inc., Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

[[Page 72468]]


ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Bombardier, Inc., Model CL-600-2B16 (604 Variants) 
airplanes. This proposed AD was prompted by reports of cracks being 
found on the lower wing plank at the rear spar wing station (WS) 59 to 
WS 65 web and/or flange. This proposed AD would require inspecting the 
lower wing plank rear spar web and lower flange, the forward surface of 
the pressure bulkhead frame under the stiffeners, and the vertical 
stabilizer front spar to frame attachment fitting lower legs for 
cracks, and repair or rectification if applicable. 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 December 
28, 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 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-2026-13808; 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

    <bullet> 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 <a href="/cdn-cgi/l/email-protection#9ecaddb0dff7ece9f1eceaf6f7f0fbededdaf7ecfbfdeaf7e8fbedb3ddf1f0edf7f9f0fbedfafbf0ffe8f7f9fffcf7f2f7eafbb0cadddeeafdb0f9fdb0fdff"><span class="__cf_email__" data-cfemail="cf9b8ce18ea6bdb8a0bdbba7a6a1aabcbc8ba6bdaaacbba6b9aabce28ca0a1bca6a8a1aabcabaaa1aeb9a6a8aeada6a3a6bbaae19b8c8fbbace1a8ace1acae">[email&#160;protected]</span></a>. You may find this material on the 
Transport Canada website at tc.canada.ca/en/aviation. It is also 
available at <a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-13808.
    <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.

FOR FURTHER INFORMATION CONTACT: Christopher Spencer, Aviation Safety 
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; 
phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#edd4c08c9b9ec083948c8e82c08e829ead8b8c8cc38a829b"><span class="__cf_email__" data-cfemail="f9c0d4988f8ad49780989a96d49a968ab99f9898d79e968f">[email&#160;protected]</span></a>.

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-2026-13808; 
Project Identifier MCAI-2024-00785-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 
<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 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 
Christopher Spencer, Aviation Safety Engineer, FAA, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#556c78342326783b2c34363a78363a26153334347b323a23"><span class="__cf_email__" data-cfemail="5a63773b2c297734233b3935773935291a3c3b3b743d352c">[email&#160;protected]</span></a>. 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-2024-47, dated December 23, 2024 
(Transport Canada AD CF-2024-47) (also referred to as the MCAI), to 
correct an unsafe condition for certain Bombardier, Inc. Model CL-600-
2B16 (604 Variants) airplanes. The MCAI states that there were reports 
of cracks being found on the lower wing plank at the rear spar WS 59 to 
WS 65 web and/or flange. Further investigation revealed that six non-
destructive testing manual procedures associated with airworthiness 
limitations tasks could lead to undetected cracks, which could lead to 
structural failure of the airplane.
    The FAA is proposing 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-2026-13808.

Material Incorporated by Reference Under 1 CFR Part 51

    Transport Canada AD CF-2024-47 specifies procedures for eddy 
current and ultrasonic inspections for cracks of the lower wing plank 
at the rear spar web WS 59 to WS 65 and lower flange, the forward 
surface of the pressure bulkhead frame under the stiffeners between 
left buttock line 9.00 and right buttock line 9.00 at fuselage station 
409.00, and the vertical stabilizer front spar to frame attachment 
fitting lower legs at fuselage station 755.00; it also specifies 
procedures for repair or rectification of cracks.
    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.

[[Page 72469]]

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in Transport Canada AD CF-2024-47 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-2024-47 by reference 
in the FAA final rule. This proposed AD would, therefore, require 
compliance with Transport Canada AD CF-2024-47 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-2024-47 for compliance will be available at 
<a href="http://regulations.gov">regulations.gov</a> under Docket No. FAA-2026-13808 after the FAA final 
rule is published.

Interim Action

    The FAA considers that this proposed AD would be an interim action. 
If final action is later identified, the FAA might consider further 
rulemaking then.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 201 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                Labor cost                  Parts cost        Cost per product          Cost on U.S. operators
----------------------------------------------------------------------------------------------------------------
Up to 24 work-hours x $85 per hour =                $0  Up to $2,040...............  Up to $410,040.
 $2,040.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs or rectifications specified in 
this proposed 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

    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:
    Bombardier, Inc.: Docket No. FAA-2026-13808; Project Identifier 
MCAI-2024-00785-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by December 28, 2026.

 (b) Affected ADs

    None.

 (c) Applicability

    This AD applies to Bombardier, Inc., Model CL-600-2B16 (604 
Variants) airplanes, certificated in any category, as identified in 
Transport Canada AD CF-2024-47, dated December 23, 2024 (Transport 
Canada AD CF-2024-47).

 (d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage; 
55, Stabilizers; and 57, Wings.

 (e) Unsafe Condition

    This AD was prompted by reports of cracks being found on the 
lower wing plank at the rear spar wing station 59 to wing station 65 
web and/or flange. The FAA is issuing this AD to address undetected 
cracks. The unsafe condition, if not addressed, could result in 
structural failure of the airplane.

 (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-2024-47.

 (h) Exception to Transport Canada AD CF-2024-47

    Where Transport Canada AD CF-2024-47 refers to its effective 
date, this AD requires using the effective date of this AD.

 (i) No Reporting Requirement

    Although the material referenced in Transport Canada AD CF-2024-
47 specifies to submit certain information to the manufacturer, this 
AD does not include that requirement.

[[Page 72470]]

 (j) Additional AD Provisions

    The following provisions also apply to this AD:
    (1) 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#c0818d8f8380a6a1a1eea7afb6"><span class="__cf_email__" data-cfemail="a7e6eae8e4e7c1c6c689c0c8d1">[email&#160;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, International 
Validation Branch, FAA; or Transport Canada; or Bombardier'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 Christopher Spencer, 
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: 516-228-7300; email: <a href="/cdn-cgi/l/email-protection#794054180f0a541700181a16541a160a391f1818571e160f"><span class="__cf_email__" data-cfemail="83baaee2f5f0aeedfae2e0ecaee0ecf0c3e5e2e2ade4ecf5">[email&#160;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 this AD specifies otherwise.
    (i) Transport Canada AD CF-2024-47, dated December 23, 2024.
    (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#90c4d3bed1f9e2e7ffe2e4f8f9fef5e3e3d4f9e2f5f3e4f9e6f5e3bdd3fffee3f9f7fef5e3f4f5fef1e6f9f7f1f2f9fcf9e4f5bec4d3d0e4f3bef7f3bef3f1"><span class="__cf_email__" data-cfemail="194d5a3758706b6e766b6d7170777c6a6a5d706b7c7a6d706f7c6a345a76776a707e777c6a7d7c77786f707e787b7075706d7c374d5a596d7a377e7a377a78">[email&#160;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#6c0a1e4205021f1c090f180503022c020d1e0d420b031a"><span class="__cf_email__" data-cfemail="5c3a2e7235322f2c393f283533321c323d2e3d723b332a">[email&#160;protected]</span></a>.

    Issued on November 5, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2026-22899 Filed 11-9-26; 8:45 am]
BILLING CODE 4910-13-P


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