Airworthiness Directive · Amendment 39-22650 · Turbine engine compressor section
General Electric Company Engines
This AD applies to General Electric Company (GE) Model GE90-90B and GE90-94B engines with interstage HPT seals listed in Table 1 to Paragraph (c) of this AD and GE90-110B1 and GE90-115B engines with an installed high-pressure turbine (HPT) stage 1 disk, HPT stage 2 disk, forward HPT rotor seal, or stages 7-9 compressor rotor spool part number (P/N) and serial number (S/N) identified in Table 1 to Paragraph (c) of this AD, or identified in Paragraph 4. APPENDIX—A, Tables 1, 2, or 3, of GE GE90-100 Service Bulletin (SB) 72-0914, dated January 25, 2023 (GE90-100 SB 72-0914).
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 disks, HPT stage 2 disks, forward HPT rotor seals, interstage HPT seals, and stages 7-9 compressor rotor spools were manufactured from powder metal material suspected to contain iron inclusion. This AD requires replacement of affected HPT stage 1 disks, HPT stage 2 disks, forward HPT rotor seals, interstage HPT seals, and stages 7-9 compressor rotor spools. The FAA is issuing this AD to address the unsafe condition on these products.
At the applicable times specified in paragraphs (g)(1) through (6) of this AD, remove each affected HPT stage 1 disk, HPT stage 2 disk, forward HPT rotor seal, interstage HPT seal, and stages 7-9 compressor rotor spool from service and replace with a part eligible for installation.
(1) For HPT stage 1 disks, before further flight.
(2) For HPT stage 2 disks with a part number and serial number identified in Paragraph 4. APPENDIX—A, Table 1 of GE90-100 SB 72-0914, at the next piece part exposure or before exceeding 3,500 cycles since new (CSN), whichever occurs first.
(3) For HPT stage 2 disks with a part number and serial number identified in Table 1 to paragraph (c) of this AD, before further flight.
(4) For forward HPT rotor seals with a part number and serial number identified in Paragraph 4. APPENDIX—A, Table 3 of GE90-100 SB 72-0914, at the next piece part exposure or before exceeding 14,200 CSN, whichever occurs first.
(5) For interstage HPT seals, at the next piece part exposure or before exceeding 12,600 CSN, whichever occurs first.
(6) For stages 7-9 compressor rotor spools, at the next piece part exposure or before exceeding the cyclic removal thresholds identified in Paragraph 4. APPENDIX—A, Table 2 of GE90-100 SB 72-0914, whichever occurs first.
For the purpose of this AD, a “part eligible for installation” is any HPT stage 1 disk, HPT stage 2 disk, stages 7-9 compressor rotor spool, forward HPT rotor seal, or interstage HPT seal with a part number and serial number that is not identified in paragraph (c) of this AD.
