Airworthiness Directive · Amendment 39-22904 · Turbine engine compressor section
CFM International, S.A. Engines
This AD applies to CFM International, S.A. (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 having an engine serial number (ESN) identified in Table 1 to paragraph (c) of this AD.
| ESN | ESN | ESN | ESN | ESN |
|---|---|---|---|---|
| 60A635 | 60A647 | 60A662 | 60A682 | 60A702 |
| 60A639 | 60A650 | 60A663 | 60A686 | |
| 60A642 | 60A653 | 60A670 | 60A687 | |
| 60A643 | 60A655 | 60A671 | 60A689 | |
| 60A644 | 60A656 | 60A673 | 60A690 | |
| 60A645 | 60A660 | 60A678 | 60A691 | |
| 60A646 | 60A661 | 60A679 | 60A696 |
The FAA is adopting a new airworthiness directive (AD) for certain CFM International, S.A. (CFM) Model LEAP-1B engines. This AD was prompted by a report of a quality escape involving certain high- pressure compressor (HPC) stage 2 seals manufactured without detailed finish machining, which could result in deeper rubs and mechanical damage to the seal teeth of the stage 3-4 compressor rotor blisk (stage 3-4 blisk) of the mating compressor rotor during initial operation. This AD requires a visual inspection of the HPC stage 2 seal, a visual inspection of the forward arm seal teeth of the stage 3-4 blisk, an eddy current inspection (ECI) of the forward arm seal teeth of the stage 3-4 blisk, and replacement of the HPC stage 2 seal and the stage 3-4 blisk, if necessary. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Before accumulating 2,900 cycles since new (CSN) or within 10 flight cycles after the effective date of this AD, whichever occurs later, perform the following:
(i) A visual inspection of the HPC stage 2 seal in accordance with the Accomplishment Instructions, paragraph 5.B.(3) of CFM Service Bulletin LEAP-1B-72-00-0394-01A-930A-D, Issue 002-00, dated January 23, 2024 (CFM SB LEAP-1B-72-00-0394-01A-930A-D, Issue 002-00).
(ii) A visual inspection of the forward arm seal teeth of the stage 3-4 blisk in accordance with the Accomplishment Instructions, paragraph 5.B.(4) of CFM SB LEAP-1B-72-00-0394-01A-930A-D, Issue 002-00.
(iii) An eddy current inspection of the forward arm seal teeth of the stage 3-4 blisk in accordance with the Accomplishment Instructions, paragraph 5.B.(5) of CFM SB LEAP-1B-72-00-0394-01A-930A-D, Issue 002-00.
(2) If, during the inspection required by paragraph (g)(1)(i) of this AD, any of the HPC stage 2 seal segments fail to meet the serviceability criteria specified in the Accomplishment Instructions, paragraph 5.B.(3) of CFM SB LEAP-1B-72-00-0394-01A-930A-D, Issue 002-00, before further flight, remove the unserviceable HPC stage 2 seal segments from service.
(3) If, during the inspections required by paragraphs (g)(1)(ii) and (iii) of this AD, the stage 3-4 blisk fails to meet the serviceability criteria specified in the Accomplishment Instructions, paragraph 5.B.(6) of CFM SB LEAP-1B-72-00-0394-01A-930A-D, Issue 002-00, before further flight:
(i) Remove the stage 3-4 blisk from service;
(ii) Remove all four HPC stage 2 seal segments from service; and
(iii) Replace the stage 3-4 blisk in accordance with the Accomplishment Instructions, paragraph 5.B.(7)(a) of CFM SB LEAP-1B-72-00-0394-01A-930A-D, Issue 002-00.
(4) If, during the actions required by paragraphs (g)(2) and (3) of this AD, the HPC stage 2 seal is removed, before further flight, replace the HPC stage 2 seal in accordance with the Accomplishment Instructions, paragraph 5.B.(7)(b) of CFM SB LEAP-1B-72-00-0394-01A-930A-D, Issue 002-00.
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.
