Airworthiness Directive · Amendment 39-22150 · Turbine section
CFM International, S.A. Turbofan Engines
This AD applies to CFM International, S.A. (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 model turbofan 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 that has accumulated more than 800 Middle East and North Africa (MENA) takeoffs.
The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) LEAP-1A model turbofan engines. This AD was prompted by reports of two in-flight shutdowns (IFSDs) 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. This AD also requires sending the inspection results to CFM if any unserviceable finding is found. The FAA is issuing this AD to address the unsafe condition on these products.
(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 800 MENA takeoffs on the HPT rotor stage 1 blade, before the HPT rotor stage 1 blade accumulates 1,750 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, paragraphs 5.E.(1)(c), of CFM Service Bulletin LEAP-1A-72-00-0461-01A-930A-D, Issue 003-00, dated July 13, 2022 (the SB).
(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, paragraphs 5.E.(1)(c), of the SB.
(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 800 MENA takeoffs on the HPT rotor stage 1 blade, before the HPT rotor stage 1 blade accumulates 2,600 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, paragraphs 5.E.(1)(c), of the SB.
(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, paragraphs 5.E.(1)(c), of the SB.
(3) BSI Results Disposition
Based on the results of the BSI required by paragraph (g)(1) or (2) of this AD, as applicable, either re-inspect or replace the HPT rotor stage 1 blades set using the criteria, compliance times, and procedures referenced in the Accomplishment Instructions, paragraph 5.E.(1)(f), of the SB.
(4) Conditional Inspection of the Sister Engine on the Same Airplane
(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 referenced in the Accomplishment Instructions, paragraph 5.E.(1)(f), of the SB, 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)(g), of the SB. Where the SB specifies to remove the engine, this AD requires replacement of the HPT rotor stage 1 blades.
(5) Reporting Requirements
If, during any inspection required by paragraph (g)(1), (2), (3), or (4) of this AD, as applicable, any HPT unserviceable finding is found on an engine as identified in the Accomplishment Instructions, paragraph 5.E.(1)(f) of the SB, within 30 days of performing the inspection, report the HPT rotor stage 1 blade unserviceable finding to CFM in accordance with the Accomplishment Instructions, paragraph 5.E.(1)(f)1, of the SB.
Note 1 to paragraph (g): The Accomplishment Instructions in paragraph 5.E.(1)(f) of the SB reference applicable aircraft maintenance manual tasks for procedures and compliance times for the actions required by paragraphs (g)(3) through (5) of this AD.
(1) Group 1 engines are CFM LEAP-1A29, LEAP-1A29CJ, LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and LEAP-1A35A model turbofan engines.
(2) Group 2 engines are CFM LEAP-1A23, LEAP-1A24, LEAP-1A24E1, LEAP-1A26, LEAP-1A26CJ, and LEAP-1A26E1 model turbofan engines.
(3) For the purpose of this AD, a “MENA takeoff” is any takeoff accomplished in the MENA region, as defined in the Planning Information, paragraph 3.D., of the SB.
(4) For the purpose of this AD, “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.
