2025-04-12: Turbine Section

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: 2025-04-12 CFM International, S.A.: Amendment 39-22970; Docket No. FAA-2024-2424; Project Identifier AD-2024-00416-E. (a) Effective Date This airworthiness directive (AD) is effective April 8, 2025. (b) Affected ADs None. (c) Applicability This AD applies to the following CFM International, S.A. (CFM) Model engines: (1) LEAP-1A23, LEAP-1A24, LEAP-1A24E1, LEAP-1A26, LEAP-1A26CJ, LEAP-1A26E1, LEAP-1A29, LEAP-1A29CJ, LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, LEAP-1A35A; (2) LEAP-1B21, LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, LEAP-1B28B2C, LEAP-1B28B3, LEAP-1B28BBJ1, LEAP-1B28BBJ2; and (3) LEAP-1C28, LEAP-1C30, and LEAP-1C30B1. (d) Subject Joint Aircraft System Component (JASC) Code 7250, Turbine Section. (e) Unsafe Condition This AD was prompted by a manufacturer investigation that revealed a quality escape for certain low-pressure turbine (LPT) disks made from forgings with nonconforming grain size. The FAA is issuing this AD to prevent the fracture and uncontained failure of certain LPT stage 4 and stage 5 disks. The unsafe condition, if not addressed, could result in uncontained part release, damage to the engine, and damage to the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions (1) For LEAP-1A engines with an installed LPT stage 5 disk having a part number (P/N) and serial number (S/N) listed in Table 1, Table 2, or Table 3 of CFM Service Bulletin (SB) LEAP-1A-72-00-0519-01A-930A-D, Issue 001-00, dated September 18, 2024 (CFM SB LEAP-1A-72-00-0519-01A-930A-D): At the next piece-part exposure of the LPT stage 5 disk, or before exceeding the applicable cycles since new (CSN) threshold identified in Table 1, Table 2, or Table 3 of CFM SB LEAP-1A-72-00-0519-01A-930A-D, whichever occurs first after the effective date of this AD, remove the LPT stage 5 disk from service and replace with a part eligible for installation. (2) For LEAP-1B engines with an installed LPT stage 4 disk having a P/N and S/N listed in Table 1 of CFM SB LEAP-1B-72-00-0419-01A-930A-D, Issue 001-00, dated September 18, 2024 (CFM SB LEAP-1B-72-00-0419-01A-930A-D): At the next piece-part exposure of the LPT stage 4 disk, or before exceeding the applicable CSN threshold identified in Table 1 of CFM SB LEAP-1B-72-00-0419-01A-930A-D, whichever occurs first after the effective date of this AD, remove the LPT stage 4 disk from service and replace with a part eligible for installation. (3) For LEAP-1B engines with an installed LPT stage 5 disk having a P/N and S/N listed in Table 2 or Table 3 of CFM SB LEAP-1B-72-00-0419-01A-930A-D: At the next piece-part exposure of the LPT stage 5 disk, or before exceeding the applicable CSN threshold identified in Table 2 or Table 3 of CFM SB LEAP-1B-72-00-0419-01A-930A-D, whichever occurs first after the effective date of this AD, remove the LPT stage 5 disk from service and replace with a part eligible for installation. (h) Installation Prohibition (1) After the effective date of this AD, do not install an LPT stage 5 disk that has a P/N and S/N identified in Table 1, Table 2, or Table 3, of CFM SB LEAP-1A-72-00-0519-01A-930A-D, in any LEAP-1A engine. (2) After the effective date of this AD, do not install an LPT stage 4 disk or LPT stage 5 disk that has a P/N and S/N identified in Table 1, Table 2, or Table 3, of CFM SB LEAP-1B-72-00-0419-01A-930A-D in any LEAP-1B engine. (3) After the effective date of this AD, do not install an LPT stage 5 disk that has a P/N and S/N identified in Table 1 of CFM SB LEAP-1C-72-00-0100-01A-930A-D, Issue 001-00, dated September 18, 2024, in any LEAP-1C engine. (i) Definitions For the purpose of this AD: (1) "LEAP-1A engines" are CFM Model LEAP-1A23, LEAP-1A24, LEAP-1A24E1, LEAP-1A26, LEAP-1A26CJ, LEAP-1A26E1, LEAP-1A29, LEAP-1A29CJ, LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and LEAP-1A35A engines. (2) "LEAP-1B engines" are CFM Model LEAP-1B21, LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, LEAP-1B28B2C, LEAP-1B28B3, LEAP-1B28BBJ1, and LEAP-1B28BBJ2 engines. (3) "LEAP-1C engines" are CFM Model LEAP-1C28, LEAP-1C30, and LEAP-1C30B1 engines. (4) A "part eligible for installation" on a LEAP-1A engine is an LPT stage 5 disk that does not have a P/N and S/N identified in Table 1, Table 2, or Table 3 of CFM SB LEAP-1A-72-00-0519-01A-930A-D. (5) A "part eligible for installation" on a LEAP-1B engine is an LPT stage 4 disk or LPT stage 5 disk that does not have a P/N and S/N identified in Table 1, Table 2, or Table 3 of CFM SB LEAP-1B-72-00-0419-01A-930A-D. (j) Alternative Methods of Compliance (AMOCs) (1) The Manager, AIR-520 Continued Operational Safety 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 local Flight Standards District Office, as appropriate. If sending information directly to the manager of the AIR-520 Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (k) of this AD and email to: AMOC@faa.gov . (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office. (k) Additional Information For more information about this AD, contact Mehdi Lamnyi, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7743; email: mehdi.lamnyi@faa.gov . (l) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) 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 the AD specifies otherwise. (i) CFM Service Bulletin (SB) LEAP-1A-72-00-0519-01A-930A-D, Issue 001-00, dated September 18, 2024. (ii) CFM SB LEAP-1B-72-00-0419-01A-930A-D, Issue 001-00, dated September 18, 2024. (iii) CFM SB LEAP-1C-72-00-0100-01A-930A-D, Issue 001-00, dated September 18, 2024. (3) For CFM material identified in this AD, contact CFM International, S.A., GE Aviation Fleet Support, 1 Neumann Way, M/D Room 285, Cincinnati, OH 45215; phone: (877) 432-3272; email: aviation.fleetsupport@ge.com . (4) You may view this material at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110. (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 21, 2025. Peter A. White, Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service. [FR Doc. 2025-03459 Filed 3-3-25; 8:45 am]BILLING CODE 4910-13-P