Airworthiness Directive · Amendment 39-23215 · Turbine section
General Electric Company Engines
This AD applies to the following General Electric Company (GE) Model engines:
(1) GE90-90B and GE90-94B engines with a high pressure turbine (HPT) stage 1 disk having a part number and serial number identified in table 1 to paragraph (c) of this AD installed; and
(2) GE90-110B1 and GE90-115B engines with an HPT stage 1 disk or HPT stage 2 disk having a part number and serial number identified in table 1 to paragraph (c) of this AD or Table 1 or Table 2 of GE GE90-100 Service Bulletin (SB) 72-0926, Revision 01, dated December 22, 2023 (GE GE90-100 SB 72-0926, Revision 01), installed.
| Part name | Part No. | Serial No. |
|---|---|---|
| HPT Stage 1 Disk | 1847M95G01 | GWN05K5J |
| HPT Stage 1 Disk | 1847M95G01 | GWN05K5M |
| HPT Stage 1 Disk | 1847M95G01 | GWN05NP6 |
| HPT Stage 1 Disk | 1865M13G08 | GWN10N9A |
| HPT Stage 1 Disk | 1865M13G07 | GWN0NJ92 |
| HPT Stage 1 Disk | 1865M13G07 | GWN0NJ94 |
| HPT Stage 1 Disk | 1865M13G07 | GWN0NK87 |
| HPT Stage 1 Disk | 1865M13G08 | GWN0RJ4G |
| HPT Stage 1 Disk | 1865M13G08 | GWN0WPEC |
| HPT Stage 2 Disk | 1865M14P04 | TMT4RK67 |
| HPT Stage 2 Disk | 1865M14P04 | TMT4RG10 |
| HPT Stage 2 Disk | 1865M14P04 | TMT4RG11 |
The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) Model GE90-90B, GE90-94B, GE90- 110B1, and GE90-115B engines. This AD was prompted by a manufacturer investigation that revealed certain high-pressure turbine (HPT) stage 1 and HPT stage 2 disks were manufactured from powder metal material suspected to contain iron inclusion. This AD requires replacement of affected HPT stage 1 and HPT stage 2 disks with parts eligible for installation. The FAA is issuing this AD to address the unsafe condition on these products.
At the applicable times specified in paragraphs (g)(1) through (3) of this AD, remove each affected HPT stage 1 disk and HPT stage 2 disk from service and replace with a part eligible for installation.
(1) For HPT stage 1 disks and HPT stage 2 disks with a part number and serial number identified in table 1 to paragraph (c) of this AD, before further flight.
(2) For HPT stage 1 disks with a part number and serial number identified in Table 1 of GE GE90-100 SB 72-0926, Revision 01, that are not identified in table 1 to paragraph (c) of this AD, at the next piece-part exposure or before exceeding 4,650 cycles since new (CSN), whichever occurs first.
(3) For HPT stage 2 disks with a part number and serial number identified in Table 2 of GE GE90-100 SB 72-0926, Revision 01, that are not identified in table 1 to paragraph (c) of this AD, at the next piece-part exposure or before exceeding 11,300 CSN, whichever occurs first.
For affected HPT stage 1 disks having greater than 4,650 CSN on the effective date of this AD, the replacement required by paragraph (g)(2) of this AD may be deferred up to 50 flight cycles after the effective date of this AD.
(1) For the purpose of this AD, a “part eligible for installation” is any HPT stage 1 disk or HPT stage 2 disk having a part number and serial number that is not identified in table 1 to paragraph (c) of this AD or Table 1 or Table 2 of GE GE90-100 SB 72-0926, Revision 01.
(2) For the purpose of this AD, a “piece-part exposure” is when the affected HPT stage 1 disk or HPT stage 2 disk is removed from the engine and completely disassembled.
