Rule2026-06506
Airworthiness Directives; 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
April 3, 2026
Effective
May 8, 2026
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all Bombardier Inc. Model CL-600-1A11 (600), CL-600-2A12 (601), and CL-600- 2B16 (601-3A, 601-3R, and 604 Variants) airplanes. This AD was prompted by a report of uncommanded nose wheel steering upon landing with touchdown on the runway centerline. This AD requires replacing the nosewheel steering rudder pedal potentiometer universal coupling setscrews. This AD also requires revising the existing maintenance or inspection program, as applicable, to incorporate new life limits for the setscrews. 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 64 (Friday, April 3, 2026)</title>
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[Federal Register Volume 91, Number 64 (Friday, April 3, 2026)]
[Rules and Regulations]
[Pages 16818-16821]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2026-06506]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2025-1732; Project Identifier MCAI-2024-00249-T;
Amendment 39-23296; AD 2026-07-01]
RIN 2120-AA64
Airworthiness Directives; 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 all
Bombardier Inc. Model CL-600-1A11 (600), CL-600-2A12 (601), and CL-600-
2B16 (601-3A, 601-3R, and 604 Variants) airplanes. This AD was prompted
by a report of uncommanded nose wheel steering upon landing with
touchdown on the runway centerline. This AD requires replacing the
nosewheel steering rudder pedal potentiometer universal coupling
setscrews. This AD also requires revising the existing maintenance or
inspection program, as applicable, to incorporate new life limits for
the setscrews. The FAA is issuing this AD to address the unsafe
condition on these products.
DATES: This AD is effective May 8, 2026.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of May 8, 2026.
ADDRESSES:
AD Docket: You may examine the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-1732; 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 Bombardier material identified in this AD, contact
Bombardier Business
[[Page 16819]]
Aircraft Customer Response Center, 400 C[ocirc]te Vertu Road West,
Dorval, Qu[eacute]bec H4S 1Y9, Canada; telephone 514-855-2999; email
<a href="/cdn-cgi/l/email-protection#8eefeda0f7fbe2ceefebfce1a0ece1e3eceffceae7ebfca0ede1e3"><span class="__cf_email__" data-cfemail="1372703d6a667f537276617c3d717c7e717261777a76613d707c7e">[email protected]</span></a>; website <a href="https://my.bombardier.com">https://my.bombardier.com</a>.
<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-2025-1732.
FOR FURTHER INFORMATION CONTACT: John Massey, Aviation Safety Engineer,
FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-
228-7300; email <a href="/cdn-cgi/l/email-protection#221b0f4354510f4c5b43414d0f414d51624443430c454d54"><span class="__cf_email__" data-cfemail="2b12064a5d580645524a4844064844586b4d4a4a054c445d">[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 all Bombardier Inc.
Model CL-600-1A11 (600), CL-600-2A12 (601), and CL-600-2B16 (601-3A,
601-3R, and 604 Variants) airplanes. The NPRM was published in the
Federal Register on August 12, 2025 (90 FR 38713). The NPRM was
prompted by AD CF-2024-12R1, dated August 13, 2024 (Transport Canada AD
CF-2024-12R1) (also referred to as the MCAI), issued by Transport
Canada, which is the aviation authority for Canada. The MCAI states
that there has been an in-service report where upon landing with
touchdown on the runway centerline, following standard procedure, the
flight spoilers and thrust reverser were used after the nose wheel
touchdown. As the airplane speed reduced to below 80 knots, the
airplane veered to the left. The airplane was maintained on the runway
by using the rudder and by differential braking. Further investigation
determined that the nosewheel steering rudder pedal potentiometer
universal coupling setscrews were loose, causing an uncommanded
steering input.
In the NPRM, the FAA proposed to require replacing the nosewheel
steering rudder pedal potentiometer universal coupling setscrews. The
FAA also proposed revising the existing maintenance or inspection
program, as applicable, to incorporate new life limits for the
setscrews. The FAA is issuing this AD to address uncommanded nosewheel
steering due to loose nosewheel steering rudder pedal potentiometer
universal coupling setscrews. The unsafe condition, if not addressed,
could lead to a runway excursion.
You may examine the MCAI in the AD docket at <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2025-1732.
Discussion of Final Airworthiness Directive
Comments
The FAA received a comment from Bombardier. The following presents
the comments received on the NPRM and the FAA's response to each
comment.
Request To Correct a Part Name
Bombardier requested the FAA correct the part name from ``nose
wheel steering potentiometer universal coupling'' to ``nose wheel
steering rudder pedal potentiometer universal coupling.'' Bombardier
suggested that this change would reduce confusion regarding
potentiometers.
The FAA agrees with the requested use of the term ``nose wheel
steering rudder pedal potentiometer universal coupling'' throughout the
final rule. The FAA has revised this final rule accordingly.
Request To Revise References to Temporary Revisions (TR)
Bombardier requested the FAA revise the AD to change the TR
reference numbers for the CL600 and CL601 Time Limits/Maintenance
Checks (TLMC) as follows:
<bullet> Replace CL600 TLMC TR 5-165 with TR 5-167.
<bullet> Replace CL601 TLMC TR 5-269 with TR 5-272.
<bullet> Replace CL601A TLMC TR 5-283 with TR 5-286.
Bombardier noted that later revisions of the TRs specified in the
proposed AD are now available.
The FAA agrees to clarify. Paragraph (h) of this AD requires
operators to incorporate ``the information in the applicable temporary
revision'' of the specified TRs. If operators incorporate a later
revision of a TR that contains the same information as the specified TR
revision, then they are in compliance with paragraph (h) of this AD.
The FAA has reviewed the later revisions of the TRs and determined that
they do contain the same information. However, if there are changes to
procedures in later revisions, operators may request an alternative
method of compliance with this AD under the provisions of paragraph
(i)(1) of this AD. The FAA has not revised this AD in response to 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 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, and any other changes described previously,
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 the following material issued by Bombardier:
<bullet> Bombardier Service Bulletin 600-0782, dated October 30,
2023.
<bullet> Bombardier Service Bulletin 601-1114, dated October 30,
2023.
<bullet> Bombardier Service Bulletin 604-32-033, dated October 30,
2023.
<bullet> Bombardier Service Bulletin 605-32-010, dated October 30,
2023.
<bullet> Bombardier Service Bulletin 650-32-007, dated October 30,
2023.
This material contains procedures to replace the existing nosewheel
steering rudder pedal potentiometer universal coupling setscrews with
new self-locking setscrews, anaerobic retaining compound, and specified
torque, and rig the potentiometer; and perform an operational test of
the nosewheel steering system. These documents are distinct since they
apply to different airplane models.
The FAA also reviewed the following Bombardier material:
<bullet> Bombardier Challenger 600 Time Limits/Maintenance Checks
(TLMC) Temporary Revision (TR) No. TR 5-165, dated October 25, 2023.
<bullet> Bombardier Challenger 601 TLMC TR No. TR 5-269, dated
October 25, 2023.
<bullet> Bombardier Challenger 601 TLMC TR No. TR 5-283, dated
October 25, 2023.
<bullet> Bombardier Challenger 604 TLMC TR No. 5-2-73, dated
October 25, 2023.
<bullet> Bombardier Challenger 605 TLMC TR No. 5-2-29, dated
October 25, 2023.
<bullet> Bombardier Challenger 650 TLMC TR No. 5-2-5, dated October
16, 2023.
This material specifies certain life limits of the safe life items.
These documents are distinct since they apply to different airplane
models.
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.
[[Page 16820]]
Costs of Compliance
The FAA estimates that this AD affects 930 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs for Required Actions
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Setscrew replacement..................... 4 work-hours x $85 per hour $40 $380 $353,400
= $340.
----------------------------------------------------------------------------------------------------------------
The FAA has determined that revising the maintenance or inspection
program takes an average of 90 work-hours per operator, although the
agency recognizes that this number may vary from operator to operator.
Since operators incorporate maintenance or inspection program changes
for their affected fleet(s), the FAA has determined that a per-operator
estimate is more accurate than a per-airplane estimate. Therefore, the
agency estimates the average total cost per operator to be $7,650 (90
work-hours x $85 per work-hour).
The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some or all of the costs of
this 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
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:
2026-07-01 Bombardier Inc.: Amendment 39-23296; Docket No. FAA-2025-
1732; Project Identifier MCAI-2024-00249-T.
(a) Effective Date
This airworthiness directive (AD) is effective May 8, 2026.
(b) Affected ADs
None.
(c) Applicability
This AD applies to all Bombardier Inc. airplanes, certificated
in any category, identified in paragraphs (c)(1) through (3) of this
AD.
(1) Model CL-600-1A11 (600) airplanes.
(2) Model CL-600-2A12 (601) airplanes.
(3) Model CL-600-2B16 (601-3A, 601-3R, and 604 Variants)
airplanes.
(d) Subject
Air Transport Association (ATA) of America Code 32, Landing
gear.
(e) Unsafe Condition
This AD was prompted by a report of uncommanded nose wheel
steering upon landing with touchdown on the runway centerline. The
FAA is issuing this AD to address uncommanded nosewheel steering due
to loose nosewheel steering rudder pedal potentiometer universal
coupling setscrews. The unsafe condition, if not addressed, could
lead to a runway excursion.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Replacement of Universal Coupling and Nosewheel Steering Rudder
Pedal Potentiometer Universal Coupling Setscrews
For airplanes identified in paragraphs (g)(1) through (5) of
this AD: Within 36 months or 1,400 flight hours, whichever occurs
first, after the effective date of this AD, replace the nosewheel
steering rudder pedal potentiometer universal coupling setscrews
(self-locking setscrews) in accordance with Sections 2.B.(3) and
2.C. of the Accomplishment Instructions in the applicable service
bulletin identified in paragraphs (g)(1) through (5) of this AD.
(1) For Model CL-600-1A11 (600) airplanes, serial numbers 1004
through 1085 inclusive, on which the actions in Part E of Canadair
Challenger Service Bulletin 600-0380, Revision 02, have been
completed: Bombardier Service Bulletin 600-0782, dated October 30,
2023.
Note 1 to paragraph (g)(1): This note applies to paragraphs
(g)(1) and (h)(1) of this AD. These airplanes are also referred to
by the marketing designation Challenger 600.
(2) For Model CL-600-2A12 (601) airplanes, serial numbers 3001
through 3059 inclusive, on which the actions in Part D of Canadair
Challenger Service Bulletin 601-0092, Revision 01 have been
completed, and serial numbers 3060 through 3066 inclusive; and Model
CL-600-2B16 (601-3A and 601-3R Variants) airplanes, serial numbers
5001 through 5194 inclusive: Bombardier Service Bulletin 601-1114,
dated October 30, 2023.
Note 2 to paragraph (g)(2): This note applies to paragraphs
(g)(2), (h)(2), and (h)(3) of this AD. These airplanes are also
referred to by the marketing designation Challenger 601.
(3) For Model CL-600-2B16 (604 Variant) airplanes, serial
numbers 5301 through 5665 inclusive: Bombardier Service Bulletin
604-32-033, dated October 30, 2023.
Note 3 to paragraph (g)(3): This note applies to paragraphs
(g)(3) and (h)(4) of this
[[Page 16821]]
AD. These airplanes are also referred to by the marketing
designation Challenger 604.
(4) For Model CL-600-2B16 (604 Variant) airplanes, serial
numbers 5701 through 5990 inclusive: Bombardier Service Bulletin
605-32-010, dated October 30, 2023.
Note 4 to paragraph (g)(4): This note applies to paragraphs
(g)(4) and (h)(5) of this AD. These airplanes are also referred to
by the marketing designation Challenger 605.
(5) For Model CL-600-2B16 (604 Variant) airplanes, serial
numbers 6050 through 6193 inclusive: Bombardier Service Bulletin
650-32-007, dated October 30, 2023.
Note 5 to paragraph (g)(5): This note applies to paragraphs
(g)(5) and (h)(6) of this AD. These airplanes are also referred to
by the marketing designation Challenger 650.
(h) Maintenance/Inspection Program Revision
Within 60 days after the effective date of this AD, revise the
existing maintenance or inspection program, as applicable, to
incorporate the information in the applicable temporary revision
identified in paragraphs (h)(1) through (6) of this AD. The initial
compliance time for the replacement is within 96 months after the
replacement required by paragraph (g) of this AD. Using a different
document with information identical to the information in the
applicable temporary revision identified in paragraphs (h)(1)
through (6) of this AD is acceptable for compliance with the
requirements of this paragraph.
(1) For all Model CL-600-1A11 (600) airplanes: Bombardier
Challenger 600 Time Limits/Maintenance Checks (TLMC) Temporary
Revision (TR) No. TR 5-165, dated October 25, 2023.
(2) For all Model CL-600-2A12 (601) airplanes: Bombardier
Challenger 601 TLMC TR No. TR 5-269, dated October 25, 2023.
(3) For all Model CL-600-2B16 airplanes (601-3A and 601-3R
Variants): Bombardier Challenger 601 TLMC TR No. TR 5-283, dated
October 25, 2023.
(4) For Model CL-600-2B16 (604 Variant) airplanes, serial
numbers 5301 through 5665 inclusive: Bombardier Challenger 604 TLMC
TR No. 5-2-73, dated October 25, 2023.
(5) For Model CL-600-2B16 (604 Variant) airplanes, serial
numbers 5701 through 5990 inclusive: Bombardier Challenger 605 TLMC
TR No. 5-2-29, dated October 25, 2023.
(6) For Model CL-600-2B16 (604 Variant) airplanes, serial
numbers 6050 and subsequent: Bombardier Challenger 650 TLMC TR No.
5-2-5, dated October 16, 2023.
(i) 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 (j) of this AD and email to:
<a href="/cdn-cgi/l/email-protection#b1f0fcfef2f1d7d0d09fd6dec7"><span class="__cf_email__" data-cfemail="4d0c00020e0d2b2c2c632a223b">[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, 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.
(j) Additional Information
For more information about this AD, contact John Massey,
Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410,
Westbury, NY 11590; telephone 516-228-7300; email <a href="/cdn-cgi/l/email-protection#d6effbb7a0a5fbb8afb7b5b9fbb5b9a596b0b7b7f8b1b9a0"><span class="__cf_email__" data-cfemail="142d39756267397a6d75777b39777b67547275753a737b62">[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) Bombardier Challenger 600 Time Limits/Maintenance Checks
(TLMC) Temporary Revision (TR) No. TR 5-165, dated October 25, 2023.
(ii) Bombardier Challenger 601 TLMC TR No. TR 5-269, dated
October 25, 2023.
(iii) Bombardier Challenger 601 TLMC TR No. TR 5-283, dated
October 25, 2023.
(iv) Bombardier Challenger 604 TLMC TR No. 5-2-73, dated October
25, 2023.
(v) Bombardier Challenger 605 TLMC TR No. 5-2-29, dated October
25, 2023.
(vi) Bombardier Challenger 650 TLMC TR No. 5-2-5, dated October
16, 2023.
(vii) Bombardier Service Bulletin 600-0782, dated October 30,
2023.
(viii) Bombardier Service Bulletin 601-1114, dated October 30,
2023.
(ix) Bombardier Service Bulletin 604-32-033, dated October 30,
2023.
(x) Bombardier Service Bulletin 605-32-010, dated October 30,
2023.
(xi) Bombardier Service Bulletin 650-32-007, dated October 30,
2023.
(3) For Bombardier material identified in this AD, contact
Bombardier Business Aircraft Customer Response Center, 400
C[ocirc]te-Vertu Road West, Dorval, Qu[eacute]bec H4S 1Y9, Canada;
telephone 514-855-2999; email <a href="/cdn-cgi/l/email-protection#99f8fab7e0ecf5d9f8fcebf6b7fbf6f4fbf8ebfdf0fcebb7faf6f4"><span class="__cf_email__" data-cfemail="6b0a0845121e072b0a0e190445090406090a190f020e1945080406">[email protected]</span></a>; website
<a href="https://my.bombardier.com">https://my.bombardier.com</a>.
(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#7513075b1c1b06051016011c1a1b351b1407145b121a03"><span class="__cf_email__" data-cfemail="c2a4b0ecabacb1b2a7a1b6abadac82aca3b0a3eca5adb4">[email protected]</span></a>.
Issued on March 24, 2026.
Steven W. Thompson,
Acting Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2026-06506 Filed 4-2-26; 8:45 am]
BILLING CODE 4910-13-P
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