2025-04-08: Navigation

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(f), 40113, 44701. 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 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 BILLING CODE 4910-13-P ER21MR25.000 (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 ER21MR25.001 BILLING CODE 4910-13-C (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 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 accordance with the applicable parts of the Accomplishment Instructions in MHI RJ Service Bulletin 670BA-34-054, Revision E, dated January 11, 2024. (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 [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, 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 [email protected]. (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 [email protected]; 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 [email protected]. 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]BILLING CODE 4910-13-P