Airworthiness Directive · Amendment 39-22123 · 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, LEAP-1A35A model turbofan engines with engine serial number (ESN) 598-280, 598-283, 598-284, 598-291, 598-300, 598-302, 598-327, 598-572, 598-629, 598-646, 598-648, 598-659, 598-667, 598-812, 598-862, 598-909, and 599-192.
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 non-synchronous vibrations resulting in more open clearances and potential hot gas ingestion into the high- pressure turbine (HPT) rotor cavity, which may result in thermal degradation of the HPT rotor interstage seal and HPT rotor stage 2 disk. This AD requires inspection of the stage 2 HPT nozzle assembly honeycomb and HPT stator stationary seal honeycomb. Depending on the results of the inspection, this AD requires replacement of the stage 2 HPT nozzle assembly honeycomb, HPT stator stationary seal, HPT rotor interstage seal, and HPT rotor stage 2 disk. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Before reaching the lowest applicable inspection threshold in Accomplishment Instructions, paragraph 5.A.(1), Table 1 or Table 2 of CFM Service Bulletin LEAP-1A-72-00-0460-01A-930A-D, Issue 002-00, dated June 10, 2022 (the SB), as applicable to each ESN and engine rating, or within 100 cycles after the effective date of this AD, whichever occurs later, perform an inspection of the stage 2 HPT nozzle assembly honeycomb in accordance with the Accomplishment Instructions, paragraph 5.B.(3)(a) of the SB.
(2) If, during the inspection required by paragraph (g)(1) of this AD, the stage 2 HPT nozzle assembly honeycomb fails to meet the criteria in the Accomplishment Instructions, paragraphs 5.B.(3)(a)1 to 5.B.(3)(a)4 of the SB, perform the following:
(i) Before further flight, remove and replace the stage 2 HPT nozzle assembly honeycomb in accordance with the Accomplishment Instructions, paragraph 5.B.(3)(c)1 of the SB.
(ii) For engines with an installed HPT rotor interstage seal, identified by serial number in Accomplishment Instructions, paragraph 5.A.(1), Table 1 of the SB, before further flight, remove the HPT rotor interstage seal and replace with a part eligible for installation.
(iii) For engines with ESN 598-646 and ESN 598-812, before further flight, remove the HPT rotor stage 2 disk and replace with a part eligible for installation.
(iv) For Group 1 engines, or an engine that has previously operated as a Group 1 engine, before further flight, remove the HPT rotor stage 2 disk and replace with a part eligible for installation.
(3) Before reaching the lowest applicable inspection threshold in Accomplishment Instructions, paragraph 5.A.(1), Table 1 or Table 2 of the SB, as applicable to each ESN and engine rating, or within 100 cycles after the effective date of this AD, whichever occurs later, perform an inspection of the HPT stator stationary seal honeycomb in accordance with the Accomplishment Instructions, paragraph 5.B.(4)(a) of the SB.
(4) If, during the inspection required by paragraph (g)(3) of this AD, the HPT stator stationary seal honeycomb fails to meet the criteria in the Accomplishment Instructions, paragraph 5.B.(4)(a)1 to 5.B.(4)(a)3 of the SB, before further flight, replace the HPT stator stationary seal in accordance with the Accomplishment Instructions, paragraph 5.B.(4)(c)1, of the SB.
For the purpose of this AD, Group 1 engines are affected LEAP-1A30, LEAP-1A32, LEAP-1A33, LEAP-1A33B2, and LEAP-1A35A model turbofan engines.
The reporting requirements in the Accomplishment Instructions, paragraphs 5.B.(3)(a)5 and 5.B.(4)(a)4, of the SB, are not required by this AD.
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.
