[4910-13-P]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-0219; Project Identifier MCAI-2023-00764-T; Amendment
39-22755; AD 2024-10-09]
RIN 2120-AA64
Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held
by Bombardier, Inc.) Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for certain MHI
RJ Aviation ULC Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This
AD was prompted by a determination that a more restrictive airworthiness limitation is
necessary. This AD requires revising the existing maintenance or inspection program, as
applicable, to incorporate a more restrictive airworthiness limitation, as specified in a
Transport Canada AD, which is incorporated by reference. The FAA is issuing this AD to
address the unsafe condition on these products.
DATES: This AD is effective [INSERT DATE 35 DAYS AFTER DATE OF
PUBLICATION IN THE FEDERAL REGISTER].
The Director of the Federal Register approved the incorporation by reference of a
certain publication listed in this AD as of [INSERT DATE 35 DAYS AFTER DATE OF
PUBLICATION IN THE FEDERAL REGISTER].
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under Docket
No. FAA-2024-0219; 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:
• For material, contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; telephone 888663-3639; email TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca;
website tc.canada.ca/en/aviation.
• You may view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 2200 South 216th Street, Des Moines, WA. For information
on the availability of this material at the FAA, call 206-231-3195. It is also available in
the AD docket at regulations.gov under Docket No. FAA-2024-0219.
FOR FURTHER INFORMATION CONTACT: Mark Taylor, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone
516-228-7300; email 9-avs-nyaco-cos@faa.gov.
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 MHI RJ Aviation ULC Model
CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. The NPRM published in the
Federal Register on February 2, 2024 (89 FR 7299). The NPRM was prompted by AD
CF-2023-41, dated June 15, 2023, issued by Transport Canada, which is the aviation
authority for Canada (Transport Canada AD CF-2023-41) (also referred to as the MCAI).
The MCAI states that a more restrictive airworthiness limitation has been developed due

to reports of an unclear effectivity for airworthiness limitation (AWL) task number
53-41-180 in the Maintenance Requirements Manual (MRM), Part 2. If the revised task,
AWL number 53-41-180, is not performed at the required intervals, failures of the strap
modification to the fuselage station (FS) 409 + 128 bulkhead could remain undetected
and could result in the loss of the structural integrity of the airplane.
In the NPRM, the FAA proposed to require revising the existing maintenance or
inspection program, as applicable, to incorporate a more restrictive airworthiness
limitation, as specified in Transport Canada AD CF-2023-41. The FAA is issuing 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-2024-0219.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from one commenter, Air Wisconsin Airlines. The
following presents the comments received on the NPRM and the FAA’s response to each
comment.
Request for Change to Applicability
Air Wisconsin Airlines noted that the proposed applicability in paragraph (c) of
the proposed AD, which references the applicability in Transport Canada AD
CF-2023-41, does not list the applicable reference serial numbers 7946 through 8113.
The commenter requested that the proposed AD be revised to list the applicable serial
numbers, if they are the same as those listed in Transport Canada AD CF-2023-41.
The FAA disagrees with correcting the applicability of this AD. Paragraph (c) of
this AD states that the AD affects the airplanes identified in Transport Canada AD CF2023-41, which has the applicability as affecting airplanes with serial numbers 7946
through 8113. No changes have been made to this AD regarding this issue.

Request for Clarification of the Applicability of a Task
Air Wisconsin Airlines requested clarification of whether paragraph (h)(2) of the
proposed AD would require revising the maintenance or inspection program to
incorporate a revised task for all airplanes or only certain airplanes.
The FAA agrees to clarify. Revising the maintenance or inspection program to
incorporate a revised AWL task affects all airplanes identified in the applicability in
paragraph (c) of the AD. A task within an AWL might have an effectivity for specific
airplanes. No changes have been made to this AD regarding this issue.
Request for Clarification of the Fuselage Station of the Strap Modification
Air Wisconsin Airlines requested that paragraph (e) of the proposed AD regarding
the location of the strap modification be changed from “(FS) 409 and 128” to “(FS) 409 +
128”. MHI RJ TR 2B-2283 lists the aircraft station as “fuselage (FS) 409 + 128
bulkhead.” In the NPRM, the location is listed as “(FS) 409 and 128 bulkhead,” which
sounds like 2 different locations.
The FAA agrees with the commenter. The FAA has confirmed with the
manufacturer that the location of the strap modification is FS 409 + 128. The FAA has
changed this final rule to reflect the proper location.
Conclusion
This product has been approved by the aviation authority of another country and
is approved for operation in the United States. Pursuant to the FAA’s bilateral agreement
with this State of Design Authority, it has notified the FAA of the unsafe condition
described in the MCAI referenced above. The FAA reviewed the relevant data,
considered the 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 this product. 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.
Related Service Information Under 1 CFR Part 51
Transport Canada AD CF-2023-41 specifies procedures for a more restrictive
airworthiness limitation for AWL task number 53-41-180. 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 78 airplanes of U.S. registry. The FAA
estimates the following costs to comply with this AD:
The FAA has determined that revising the existing 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 workhours × $85 per work-hour).
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
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
§ 39.13 [Amended]
2. The FAA amends § 39.13 by adding the following new airworthiness directive:
2024-10-09 MHI RJ Aviation ULC (Type Certificate Previously Held by
Bombardier, Inc.): Amendment 39-22755; Docket No. FAA-2024-0219; Project
Identifier MCAI-2023-00764-T.

(a) Effective Date
This airworthiness directive (AD) is effective [INSERT DATE 35 DAYS AFTER
DATE OF PUBLICATION IN THE FEDERAL REGISTER].
(b) Affected ADs
None.
(c) Applicability
This AD applies to MHI RJ Aviation ULC (Type Certificate previously held by
Bombardier, Inc.) Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes,
certificated in any category, as identified in Transport Canada AD CF-2023-41, dated
June 15, 2023 (Transport Canada AD CF-2023-41).
(d) Subject
Air Transport Association (ATA) of America Code 05, Time Limits/Maintenance
Checks.
(e) Unsafe Condition
This AD was prompted by a determination that a more restrictive airworthiness
limitation is necessary. The FAA is issuing this AD to address failure of the strap
modification to the fuselage station (FS) 409 + 128 bulkhead. The unsafe condition, if not
addressed, could result in the loss of the structural integrity 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-2023-41.
(h) Exception to Transport Canada AD CF-2023-41
(1) Where Transport Canada AD CF-2023-41 refers to its effective date, this AD

requires using the effective date of this AD.
(2) Where paragraph A. of Transport Canada AD CF-2023-41 specifies to
“incorporate the revised task AWL number 53-41-180 in Appendix B of the MRM CSP
A-053 Part 2,” this AD requires replacing that text with “revise the existing maintenance
or inspection program, as applicable, by incorporating the revised task AWL number 5341-180 specified in MHI RJ Temporary Revision 2B-2283, dated March 16, 2023.”
(3) The initial compliance time for doing the task specified in paragraph A. of
Transport Canada AD CF-2023-41 is at the applicable “threshold” as specified in the
service information referenced in paragraph B. of Transport Canada AD CF-2023-41, or
within 60 days after the effective date of this AD, whichever occurs later.
(4) This AD does not adopt paragraph B. of Transport Canada AD CF-2023-41.
(i) Provisions for Alternative Actions and Intervals
After the existing maintenance or inspection program has been revised as required
by paragraph (g) of this AD, no alternative actions (e.g., inspections) and intervals are
allowed unless they are approved as specified in the provisions of the “Corrective
Actions” section of Transport Canada AD CF-2023-41.
(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, mail it to the address identified in paragraph (k) of this AD or email to: 9-AVSNYACO-COS@faa.gov. If mailing information, also submit information by email.
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 MHI RJ Aviation ULC’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 Mark Taylor, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone
516-228-7300; email 9-avs-nyaco-cos@faa.gov.
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the incorporation by reference
(IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR
part 51.
(2) You must use this service information as applicable to do the actions required
by this AD, unless this AD specifies otherwise.
(i) Transport Canada AD CF-2023-41, dated June 15, 2023.
(ii) [Reserved]
(3) For Transport Canada AD CF-2023-41, contact Transport Canada, Transport
Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5,
Canada; phone 888-663-3639; email TC.AirworthinessDirectivesConsignesdenavigabilite.TC@tc.gc.ca. You may find this Transport Canada AD on the
Transport Canada website tc.canada.ca/en/aviation.
(4) You may view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 2200 South 216th Street, 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
fr.inspection@nara.gov.
Issued on May 15, 2024.

Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division,
Aircraft Certification Service.
[FR Doc. 2024-13016 Filed: 6/13/2024 8:45 am; Publication Date: 6/14/2024]