Airworthiness Directive · Amendment 39-23175 · Turbine section
CFM International, S.A. Engines
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.
The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (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. This AD was prompted by reports of two in-flight shutdowns and subsequent investigation by the manufacturer that revealed cracks in the high-pressure turbine (HPT) rotor stage 1 blades. This AD requires initial and repetitive borescope inspections (BSIs) of the HPT rotor stage 1 blades. Depending on the results of the BSIs, this AD requires either additional BSIs at reduced intervals or replacement of the HPT rotor stage 1 blades. The FAA is issuing this AD to address the unsafe condition on these products.
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.
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.
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.
(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.
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.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
