90 FR 54 pgs. 13278-13284 - Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier Inc.) Airplanes
Type: RULEVolume: 90Number: 54Pages: 13278 - 13284
Pages: 13278, 13279, 13280, 13281, 13282, 13283, 13284Docket number: [Docket No. FAA-2024-1896; Project Identifier MCAI-2023-00978-T; Amendment 39-22966; AD 2025-04-08]
FR document: [FR Doc. 2025-04720 Filed 3-20-25; 8:45 am]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version: PDF Version
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-1896; Project Identifier MCAI-2023-00978-T; Amendment 39-22966; AD 2025-04-08]
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 and 440), CL-600-2C10 (Regional Jet Series 700, 701, and 702), CL-600-2C11 (Regional Jet Series 550), CL-600-2D15 (Regional Jet Series 705), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. This AD was prompted by the determination that radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G C-Band). This AD requires installing a new radio frequency (RF) bandpass filter on the coaxial line between the radio altimeter and the receive antenna in the aft equipment compartment. The FAA is issuing this AD to address the unsafe condition on these products.
DATES:
[top] This AD is effective April 25, 2025.
The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of April 25, 2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2024-1896; 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 MHI RJ material identified in this AD, contact MHI RJ Aviation Group, Customer Response Center, 3655 Ave. des Grandes-Tourelles, Suite 110, Boisbriand, Québec J7H 0E2 Canada; North America toll-free telephone 833-990-7272 or direct-dial telephone 450-990-7272; fax 514-855-8501; email thd.crj@mhirj.com; website mhirj.com.
• 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 regulations.gov under Docket No. FAA-2024-1896.
FOR FURTHER INFORMATION CONTACT:
Steven Dzierzynski, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; email 9-avs-nyaco-cos@faa.gov.
SUPPLEMENTARY INFORMATION:
Background
The FAA issued AD 2023-10-02, Amendment 39-22438 (88 FR 34065, May 26, 2023) (AD 2023-10-02) to address the effect of interference from wireless broadband operations in the 5G C-Band on all transport and commuter category airplanes equipped with a radio altimeter. AD 2023-10-02 was prompted by a determination that radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 5G C-Band. AD 2023-10-02 requires revising the limitations section of the existing airplane flight manual to incorporate limitations prohibiting transport and commuter category airplanes from performing certain low-visibility landing operations at any airport unless they have upgraded their radio altimeters. Transport Canada, which is the aviation authority for Canada, issued corresponding Transport Canada AD CF-2023-46, dated June 30, 2023, to require similar limitations on flight operations requiring radio altimeter data in U.S. airspace affected by 5G C-Band wireless signals.
The FAA subsequently 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 and 440), CL-600-2C10 (Regional Jet Series 700, 701, and 702), CL-600-2C11 (Regional Jet Series 550), CL-600-2D15 (Regional Jet Series 705), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. The NPRM published in the Federal Register on September 9, 2024 (89 FR 73009). The NPRM was prompted by AD CF-2023-62R1, dated November 21, 2023, issued by Transport Canada, which is the aviation authority for Canada (referred to after this as the MCAI). The MCAI states that, in addition to the effects of 5G C-Band broadband interference identified in FAA AD 2023-10-02, MHI RJ has determined that 5G C-Band broadband interference can result in certain failure messages and aural alerts being inhibited longer than intended. Specifically, this can result in the inhibition of hydraulic system #3 and wing anti-ice overheat failure messages such that flightcrew are unable to perform appropriate airplane flight manual (AFM) procedures in the time needed to prevent loss of elevator control due to hydraulic system overheat and wing structural damage due to wing anti-ice system overheat. This condition, if not corrected, could result in delayed flightcrew response leading to loss of continued safe flight and landing.
In the NPRM, the FAA proposed to require installing a new RF bandpass filter on the coaxial line between the radio altimeter and the receive antenna in the aft equipment compartment. When the airplane is modified as specified in this AD, the configuration with the RF bandpass filter installed has been determined to be "radio altimeter tolerant." The FAA is issuing this AD because radio altimeter anomalies can result in the inhibition of certain failure messages such that the flightcrew are unable to perform appropriate airplane flight manual procedures in the time needed to prevent potential ignition hazard due to overheated hydraulic fluid circulating in the fuel tanks area, which may lead to loss of continued safe flight and landing, and/or structural deformation of the wing leading edge which may reduce the safety margin (to stall).
You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA-2024-1896.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from Mesa Airlines, MHI RJ Aviation (MHI RJ), and an individual commenter. The following presents the comments received on the NPRM and the FAA's response to each comment.
Request To Refer To Revised Service Information
MHI RJ and an individual commenter requested that the proposed AD be revised to refer to revised service bulletins. The individual commenter noted that MHI RJ Service Bulletin 670BA-34-054 is currently at Revision E. MHI RJ stated that the original issue and Revisions A, B, C, D, and E of MHI RJ Service Bulletin 670BA-34-054; and Revisions D and E of MHI RJ Service Bulletin 601R-34-152 should be listed as methods of compliance for the actions required by the proposed AD. MHI RJ also requested that all acceptable revisions of the referenced service information be added to paragraph (n) of the proposed AD.
[top] The FAA agrees to refer to the latest revisions of the service information. MHI RJ Service Bulletin 601R-34-152, Revision E, dated June 29, 2023, includes minor editorial changes (adding reference to an FAA AD and additional reference documents; and revising recommended compliance times, though the FAA notes that the compliance times in this AD take precedence over those in the service information). Those changes do not have an effect on the technical content and no additional work is necessary for operators that incorporated MHI RJ Service Bulletin 601R-34-152, Revision D, dated May 11, 2023. MHI RJ Service Bulletin 670BA-34-054, dated February 20, 2023; Revision A, dated February 28, 2023; Revision B, dated March 28, 2023; Revision C, dated June 29, 2023; Revision D, dated August 31, 2023; and Revision E, dated January 11, 2024; contain minor editorial revisions that do not have an effect on the technical content or require additional work for operators that incorporated earlier revisions. Therefore, the FAA has revised this AD to refer to MHI RJ Service Bulletin 670BA-34-054, Revision E, dated January 11, 2024; and MHI RJ Service Bulletin 601R-34-152, Revision E, dated June 29, 2023.
Regarding the request to cite all acceptable revisions of the service information in paragraph (n) of this AD, the FAA notes that paragraph (n) of this AD identifies only material that is to be incorporated by reference in the AD, and this AD requires and incorporates by reference only Revision E of the service bulletins, as specified in paragraphs (h), (i), and (j) of this AD.
Requests To Revise Credit for Previous Actions
An individual commenter requested that the FAA revise paragraph (k) of the proposed AD to include credit for actions performed using the original issue or Revisions A, B, C, or D of MHI RJ Service Bulletin 670BA-34-054. MHI RJ requested revising the conditional credit specified in the introductory text of paragraph (k) of the proposed AD to specify an additional document. MHI RJ noted that credit is conditional on operators installing the electrical idents for coax cables using Part G of MHI RJ Service Bulletin 601R-34-152, which is included only in Revisions D and E of that service information. MHI RJ also stated that some operators may have used, and should be granted credit for, Service Non-Incorporated Engineering Order (SNIEO) KCM601R53009-S01, which provides instructions for fabricating and installing electrical idents, and which is equivalent to Part G of Revision D and Revision E of MHI RJ Service Bulletin 601R-34-152.
The FAA agrees with the commenters' requests. The FAA has revised paragraph (k) of this AD as follows:
• Revised paragraph (k)(1) of this AD to refer to MHI RJ Service Bulletin 601R-34-152, Revision E, dated June 29, 2023.
• Added paragraph (k)(2) of this AD to provide credit for actions done using certain revisions of MHI RJ Service Bulletin 601R-34-152 provided that idents were installed using SNIEO KCM601R53009-S01 or MHI RJ Service Bulletin 601R-34-152, Revision D, dated May 11, 2023.
• Added paragraph (k)(3) of this AD to provide credit for MHI RJ Service Bulletin 601R-34-152, Revision D, dated May 11, 2023.
• Added paragraph (k)(4) of this AD to provide credit for the original issue and Revisions A, B, C, or D of MHI RJ Service Bulletin 670BA-34-054.
Request To Clarify Applicability
Mesa Airlines requested clarification of the affected Model CL-600-2D24 (Regional Jet Series 900) airplanes in paragraph (c) of the proposed AD. The proposed AD identified manufacturer serial numbers (MSNs) 15001 through 15990, which, according to Mesa Airlines, is all Model CL-600-2D24 airplanes. The commenter noted, however, that the effectivity of MHI RJ Service Bulletin 670BA-34-054, dated February 20, 2023, is limited to selected MSNs. That service bulletin was cited in paragraph (i) of the proposed AD as the appropriate source of service information for installing the RF bandpass filter for the specified airplanes including Model CL-600-2D24 airplanes.
The FAA provides the following clarification. The effectivity in MHI RJ Service Bulletin 670BA-34-054, dated February 20, 2023, is limited to selected MSNs. According to MHI RJ, the initial issue of this service bulletin was intended for those operators interested in purchasing the modification, so the MSNs listed in that service bulletin were confirmed to be committed for purchase of the modification kits. Rather than revising the service bulletin effectivity each time a new MSN needed to be added, MHI RJ later decided to make the service bulletin applicable to all MSNs. Therefore, the effectivity in subsequent service bulletin revisions includes all MSNs. As stated previously, this AD has been changed to refer to MHI RJ Service Bulletin 670BA-34-054, Revision E, dated January 11, 2024, for the required actions for airplanes including Model CL-600-2D24 airplanes.
Request To Clarify Unsafe Condition
The Background section of the NPRM and paragraph (e) ("Unsafe Condition") of the proposed AD stated that the FAA proposed the AD because radio altimeter anomalies can result in the inhibition of certain failure messages such that the flightcrew are unable to perform appropriate AFM procedures in the time needed to prevent "loss of elevator control due to hydraulic system overheat and wing structural damage due to wing anti-ice system overheat," which could result in "delayed flightcrew response leading to loss of continued safe flight and landing." MHI RJ recommended that the FAA revise the proposed AD to state that the intent is rather to prevent "potential ignition hazard due to overheated hydraulic fluid circulating in the fuel tanks area, which may lead to loss of continued safe flight and landing, and/or structural deformation of the wing leading edge which may reduce the safety margin (to stall)."
The FAA agrees with MHI RJ's proposed text, which better clarifies the radio altimeter anomalies that can result in the inhibition of certain failure messages. The Background section and paragraph (e) of this AD have been revised accordingly.
Request To Remove Statement Related to Unsafe Condition
The Background section of the NPRM stated that MHI RJ determined that 5G C-Band broadband interference can result in certain failure messages and aural alerts being inhibited longer than intended. The Background then included the following statement:
Specifically, this can result in the inhibition of hydraulic system #3 and wing anti-ice overheat failure messages such that flightcrew are unable to perform appropriate airplane flight manual (AFM) procedures in the time needed to prevent loss of elevator control due to hydraulic system overheat and wing structural damage due to wing anti-ice system overheat. This condition, if not corrected, could result in delayed flightcrew response leading to loss of continued safe flight and landing.
MHI RJ recommended removing the quoted statement because that content is not included in Canadian AD CF-2023-46, and it is unnecessary and misleading.
The FAA agrees to clarify. The FAA acknowledges that the specified text is not included in Transport Canada AD CF-2023-46. However, the FAA has determined that the added text provides additional details for a more comprehensive background of the unsafe condition identified in this final rule.
Request To Revise a Compliance Time
MHI RJ recommended changing paragraph (j) of the proposed AD, which proposed to require installing an RF bandpass filter on Model CL-600-2E25 airplanes "before the next flight in the contiguous U.S. airspace" after the effective date of the AD. MJI RJ recommended removing "in the contiguous U.S. airspace" because the proposed AD would apply to U.S.-registered airplanes operating in any airspace.
[top] The FAA disagrees with MHI RJ's request to change this compliance time language for Model CL-600-2E25 airplanes. The language has been retained in paragraph (j) of this AD to require compliance "before the next flight in the contiguous U.S. airspace" for Model CL-600-2E25 airplanes because none of those affected airplanes are currently flying in the U.S, but the AD requirements will apply if an affected airplane is placed on the U.S. Registry and flown in the contiguous U.S. The FAA has not changed paragraph (j) of this AD as a result of this comment.
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.
Material Incorporated by Reference Under 1 CFR Part 51
The FAA reviewed MHI RJ Service Bulletins 601R-34-152, Revision E, dated June 29, 2023, and 670BA-34-054, Revision E, dated January 11, 2024. This material specifies procedures for installing a new RF bandpass filter on the coaxial line between the radio altimeter and the receive antenna in the aft equipment compartment. 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.
Costs of Compliance
The FAA estimates that this AD affects up to 873 airplanes of U.S. registry. However, many of these airplanes may already have a bandpass filter installed in compliance with AD 2023-10-02 and would not incur any additional costs to comply with this AD. The FAA estimates the following costs to comply with this AD:
| Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|
| 58 work-hours × $85 per hour = $4,930 | $53,647 | $58,577 | Up to $51,137,721. |
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(f), 40113, 44701.
§?39.13 [Amended]
2. The FAA amends §?39.13 by adding the following new airworthiness directive:
2025-04-08 MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier Inc.): Amendment 39-22966; Docket No. FAA-2024-1896; Project Identifier MCAI-2023-00978-T.
(a) Effective Date
This airworthiness directive (AD) is effective April 25, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to the MHI RJ Aviation ULC (Type Certificate previously held by Bombardier Inc.) airplanes identified in paragraphs (c)(1) through (6) of this AD, certificated in any category, that are equipped with a radio altimeter and not determined to be a radio altimeter tolerant airplane as defined in paragraph (g) of this AD.
(1) Model CL-600-2B19 (Regional Jet Series 100 and 440) airplanes, serial number (S/N) 7002 through 8113.
(2) Model CL-600-2C10 (Regional Jet Series 700, 701, and 702) airplanes, S/N 10002 through 10999.
(3) Model CL-600-2C11 (Regional Jet Series 550) airplanes, S/N 10002 through 10999.
(4) Model CL-600-2D15 (Regional Jet Series 705) airplanes, S/N 15001 through 15990.
(5) Model CL-600-2D24 (Regional Jet Series 900) airplanes, S/N 15001 through 15990.
(6) Model CL-600-2E25 (Regional Jet Series 1000) airplanes, S/N 19013 through 19990.
(d) Subject
Air Transport Association (ATA) of America Code 34, Navigation.
(e) Unsafe Condition
[top] This AD was prompted by the determination that radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G C-Band). The FAA is issuing this AD because radio altimeter anomalies can result in the inhibition of certain failure messages such that the flightcrew are unable to perform appropriate airplane flight manual procedures in the time needed to prevent potential ignition hazard due to overheated hydraulic fluid circulating in the fuel tanks area, which may lead to loss of continued safe flight and landing, and/or structural deformation of the wing leading edge which may reduce the safety margin (to stall).
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Definitions
For purposes of this AD, a "radio altimeter tolerant airplane" is one for which the radio altimeter, as installed, demonstrates the tolerances specified in paragraphs (g)(1) and (2) of this AD, using a method approved by the FAA. No actions are required by this AD for radio altimeter tolerant airplanes.
(1) Tolerance to radio altimeter interference, for the fundamental emissions (3.7-3.98 GHz), at or above the power spectral density (PSD) curve threshold specified in figure 1 to paragraph (g)(1) of this AD.
Figure 1 to Paragraph (g)(1)-Fundamental Effective Isotropic PSD at Outside Interface of Airplane Antenna
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[Federal Register graphic "ER21MR25.000" is not available. Please view the graphic in the PDF version of this document.]
(2) Tolerance to radio altimeter interference, for the spurious emissions (4.2-4.4 GHz), at or above the PSD curve threshold specified in figure 2 to paragraph (g)(2) of this AD.
Figure 2 to Paragraph (g)(2)-Spurious Effective Isotropic PSD at Outside Interface of Airplane Antenna
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[Federal Register graphic "ER21MR25.001" is not available. Please view the graphic in the PDF version of this document.]
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(h) Filter Installation: Model CL-600-2B19
For Model CL-600-2B19 airplanes: Within 2,300 flight hours or 12 months after the effective date of this AD, whichever occurs first, install a radio frequency (RF) bandpass filter on each radio altimeter in accordance with the applicable parts of the Accomplishment Instructions in MHI RJ Service Bulletin 601R-34-152, Revision E, dated June 29, 2023. Alternatively, airplanes with a dual radio altimeter configuration may comply with this paragraph by installing an RF bandpass filter on one radio altimeter and deactivating the second radio altimeter in accordance with the applicable parts of the Accomplishment Instructions in MHI RJ Service Bulletin 601R-34-152, Revision E, dated June 29, 2023.
(i) Filter Installation: Model CL-600-2C10, CL-600-2C11, CL-600-2D15, and CL-600-2D24
For Model CL-600-2C10, CL-600-2C11, CL-600-2D15, and CL-600-2D24 airplanes: Within 2,100 flight hours or 12 months after the effective date of this AD, whichever occurs first, install an RF bandpass filter on each radio altimeter in accordance with the applicable parts of the Accomplishment Instructions in MHI RJ Service Bulletin 670BA-34-054, Revision E, dated January 11, 2024. Alternatively, airplanes with a dual radio altimeter configuration may comply with this paragraph by installing an RF bandpass filter on one radio altimeter and deactivating the second radio altimeter in accordance with the applicable parts of the Accomplishment Instructions in MHI RJ Service Bulletin 670BA-34-054, Revision E, dated January 11, 2024.
(j) Filter Installation: Model CL-600-2E25
[top] For Model CL-600-2E25 airplanes: Before the next flight in the contiguous U.S. airspace after the effective date of this AD, install an RF bandpass filter on each radio altimeter in
(k) Credit for Previous Actions
(1) For Model CL-600-2B19 airplanes: This paragraph provides credit for the actions required by paragraph (h) of this AD, if those actions were performed before the effective date of this AD using the material in paragraphs (k)(1)(i) through (iv) of this AD, provided the electrical idents for coax cables are installed using Part G of the Accomplishment Instructions in MHI RJ Service Bulletin 601R-34-152, Revision E, dated June 29, 2023, within the compliance time specified in paragraph (h) of this AD.
(i) MHI RJ Service Bulletin 601R-34-152, dated February 14, 2023.
(ii) MHI RJ Service Bulletin 601R-34-152, Revision A, dated February 28, 2023.
(iii) MHI RJ Service Bulletin 601R-34-152, Revision B, dated March 28, 2023.
(iv) MHI RJ Service Bulletin 601R-34-152, Revision C, dated April 20, 2023.
(2) For Model CL-600-2B19 airplanes: This paragraph provides credit for the actions required by paragraph (h) of this AD, if those actions were performed before the effective date of this AD using the material in paragraphs (k)(2)(i) through (iv) of this AD, provided the electrical idents for coax cables were installed using Part G of the Accomplishment Instructions in MHI RJ Service Bulletin 601R-34-152, Revision D, dated May 11, 2023, or MHI RJ Service Non-Incorporated Engineering Order (SNIEO) KCM601R53009-S01, dated May 2, 2023, prior to the effective date of this AD.
(i) MHI RJ Service Bulletin 601R-34-152, dated February 14, 2023.
(ii) MHI RJ Service Bulletin 601R-34-152, Revision A, dated February 28, 2023.
(iii) MHI RJ Service Bulletin 601R-34-152, Revision B, dated March 28, 2023.
(iv) MHI RJ Service Bulletin 601R-34-152, Revision C, dated April 20, 2023.
(3) For Model CL-600-2B19 airplanes: This paragraph provides credit for the actions required by paragraph (h) of this AD, if those actions were performed before the effective date of this AD using MHI RJ Service Bulletin 601R-34-152, Revision D, dated May 11, 2023.
(4) For Model CL-600-2C10, CL-600-2C11, CL-600-2D15, CL-600-2D24, and CL-600-2E25 airplanes: This paragraph provides credit for the actions required by paragraphs (i) and (j) of this AD, as applicable, if those actions were performed before the effective date of this AD using the material in paragraphs (k)(4)(i) through (v) of this AD.
(i) MHI RJ Service Bulletin 670BA-34-054, dated February 20, 2023.
(ii) MHI RJ Service Bulletin 670BA-34-054, Revision A, dated February 28, 2023.
(iii) MHI RJ Service Bulletin 670BA-34-054, Revision B, dated March 28, 2023.
(iv) MHI RJ Service Bulletin 670BA-34-054, Revision C, dated June 29, 2023.
(v) MHI RJ Service Bulletin 670BA-34-054, Revision D, dated August 31, 2023.
(l) 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 (m)(1) of this AD. Information may be emailed to AMOC@faa.gov. 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.
(m) Additional Information
(1) For more information about this AD, contact Steven Dzierzynski, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7300; email 9-avs-nyaco-cos@faa.gov.
(2) Material identified in this AD that is not incorporated by reference is available at the address specified in paragraph (n)(3) of this AD.
(n) 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) MHI RJ Service Bulletin 601R-34-152, Revision E, dated June 29, 2023.
(ii) MHI RJ Service Bulletin 670BA-34-054, Revision E, dated January 11, 2024.
(3) For MHI RJ material identified in this AD, contact MHI RJ Aviation Group, Customer Response Center, 3655 Ave. des Grandes-Tourelles, Suite 110, Boisbriand, Québec J7H 0E2 Canada; North America toll-free telephone 833-990-7272 or direct-dial telephone 450-990-7272; fax 514-855-8501; email thd.crj@mhirj.com; website mhirj.com.
(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 fr.inspection@nara.gov.
Issued on February 18, 2025.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.
[FR Doc. 2025-04720 Filed 3-20-25; 8:45 am]
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