2025-21-03: Turbine section

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2025-21-03 CFM International, S.A.: Amendment 39-23175; Docket No. FAA-2025-3434; Project Identifier AD-2025-00473-E. (a) Effective Date This airworthiness directive (AD) is effective December 29, 2025. (b) Affected ADs None. (c) Applicability This AD applies to CFM International, S.A. Model (CFM) 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 with an installed high-pressure turbine (HPT) rotor stage 1 blade, having part number (P/N) 2747M92P01, P/N 2553M91G03, P/N 2553M91G05, P/N 2553M91G06, P/N 2553M91G07, or P/N 2553M91G08 and that has accumulated more than 1,100 South Asia takeoffs. (d) Subject Joint Aircraft System Component (JASC) Code 7250, Turbine section. (e) Unsafe Condition This AD was prompted by reports of two in-flight shutdowns due to cracks in the HPT rotor stage 1 blades. The FAA is issuing this AD to prevent failure of the HPT rotor stage 1 blades. The unsafe condition, if not addressed, could result in failure of the engine, in-flight shutdown, loss of thrust control, and consequent loss of control of the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions (1) Group 1 Engines: Borescope Inspection (BSI) of HPT Rotor Stage 1 Blades For Group 1 engines with an affected HPT rotor stage 1 blade installed: (i) Within 100 flight cycles (FCs) after accumulating 1,100 South Asia takeoffs on the HPT rotor stage 1 blade, before the HPT rotor stage 1 blade accumulates 2,500 cycles since new (CSN), or within 100 FCs after the effective date of this AD, whichever occurs later, perform an initial BSI of the HPT rotor stage 1 blades in accordance with the Accomplishment Instructions, paragraph 5.E.(1)(c), of CFM Service Bulletin LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00, dated July 30, 2025 (CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00). (ii) Thereafter, at intervals not to exceed 150 FCs since the last BSI, perform a repetitive BSI of the HPT rotor stage 1 blades in accordance with the Accomplishment Instructions, paragraph 5.E.(1)(c), of CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00. (2) Group 2 Engines: BSI of HPT Rotor Stage 1 Blades For Group 2 engines with an affected HPT rotor stage 1 blade installed: (i) Within 100 FCs after accumulating 1,100 South Asia takeoffs on the HPT rotor stage 1 blade, before the HPT rotor stage 1 blade accumulates 5,100 CSN, or within 100 FCs after the effective date of this AD, whichever occurs later, perform an initial BSI of the HPT rotor stage 1 blades in accordance with the Accomplishment Instructions, paragraph 5.E.(1)(c), of CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00. (ii) Thereafter, at intervals not to exceed 300 FCs since the last BSI, perform a repetitive BSI of the HPT rotor stage 1 blades in accordance with the Accomplishment Instructions, paragraph 5.E.(1)(c), of CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00. (3) BSI Results Disposition for Group 1 and Group 2 Engines Based on the results of the BSI required by paragraphs (g)(1) or (2) of this AD, as applicable, either re-inspect or replace, as applicable, the HPT rotor stage 1 blades set using the criteria, compliance times, and procedures as described in the Accomplishment Instructions, paragraph 5.E.(1)(e), of CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00. (4) Conditional Inspection of the Sister Engine for Group 1 and Group 2 Engines (i) Based on the BSI results disposition required by paragraph (g)(3) of this AD, if re-inspection or replacement of the HPT rotor stage 1 is required, within 50 FCs based on the criteria, compliance times, and procedures described in the Accomplishment Instructions, paragraph 5.E.(1)(e), of CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00, then perform the actions required in paragraph (g)(4)(ii) of this AD. (ii) Within 5 FCs after performing the inspection required by paragraph (g)(1) or (2) of this AD, as applicable, either inspect or replace the HPT rotor stage 1 blades on the sister engine using the procedures and compliance times in the Accomplishment Instructions, paragraph 5.E.(1)(f), of CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00. Where CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00, specifies to remove the engine, this AD requires replacement of the HPT rotor stage 1 blades. (h) Definitions For the purpose of this AD, the following definitions apply: (1) Group 1 engines are CFM Model LEAP-1A29, LEAP-1A29CJ, LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and LEAP-1A35A engines. (2) Group 2 engines are CFM Model LEAP-1A23, LEAP-1A24, LEAP-1A24E1, LEAP-1A26, LEAP-1A26CJ, and LEAP-1A26E1 engines. (3) A "South Asia takeoff" is any takeoff accomplished in the South Asia region, which includes the following countries: Bangladesh, Bhutan, India, Maldives, Nepal, and Sri Lanka. (4) A "sister engine" refers to the other engine installed on the same airplane. (i) Credit for Previous Actions (1) This paragraph provides credit for the initial BSI required by paragraphs (g)(1)(i) or (2)(i) of this AD if you performed the initial BSI before the effective date of this AD using CFM Service Bulletin LEAP-1A-72-00-0485-01A-930A-D, Issue 001-00, dated September 27, 2022, or Issue 002-00, dated April 16, 2025. (2) The inspections and corrective actions as required by paragraphs (g)(1) through (4) of this AD satisfy the requirements of paragraphs (g)(1) through (4) of AD 2022-17-12, Amendment 39-22150 (87 FR 53651, September 1, 2022) (AD 2022-17-12). (3) The inspections and corrective actions as required by paragraphs (g)(1) through (4) of AD 2022-17-12 satisfy the requirements of paragraphs (g)(1) through (4) of this AD. (j) No Reporting Requirement Where CFM SB LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00, requires reporting any unserviceable findings, this AD does not require that action. (k) 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 (l) 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. (l) 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. (m) 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 the AD specifies otherwise. (i) CFM Service Bulletin LEAP-1A-72-00-0485-01A-930A-D, Issue 003-00, dated July 30, 2025. (ii) [Reserved] (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 December 5, 2025. Peter A. White, Deputy Director, Integrated Certificate Management Division, Aircraft Certification Service. [FR Doc. 2025-22684 Filed 12-11-25; 8:45 am]BILLING CODE 4910-13-P