2023-26-07: Turbine Section

1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 2. The FAA amends § 39.13 by adding the following new airworthiness directive: 2023-26-07 General Electric Company: Amendment 39-22650; Docket No. FAA-2023-1647; Project Identifier AD-2023-00487-E. (a) Effective Date This airworthiness directive (AD) is effective February 27, 2024. (b) Affected ADs None. (c) Applicability 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). Table 1 to Paragraph (c)-Affected HPT Stage 1 and Stage 2 Disks, and Interstage HPT Seals ER23JA24.021 Note 1 to paragraph (c): Part numbers and serial numbers for affected HPT stage 1 disks, HPT stage 2 disks, and interstage HPT seals are also listed in GE GE90-100 Service Bulletin (SB) 72-0904 R00, dated May 25, 2022; GE GE90-100 SB 72-0911 R01, dated September 21, 2022; and GE GE90 SB 72-1223, dated January 25, 2023. (d) Subject Joint Aircraft System Component (JASC) Code 7230, Turbine Engine Compressor Section; 7250, Turbine Section. (e) Unsafe Condition This AD was prompted by a manufacturer investigation that revealed certain 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. The FAA is issuing this AD to prevent premature fracture and subsequent uncontained failure. The unsafe condition, if not addressed, could result in uncontained debris release, damage to the engine, and damage to the airplane. (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions 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. (h) Definition 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. (i) Alternative Methods of Compliance (AMOCs) (1) The Manager, AIR-520 Continued Operational Safety Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of AIR-520 Continued Operational Safety Branch, send it to the attention of the person identified in paragraph (j) of this AD and email to: ANE-AD-AMOC@faa.gov. (2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local Flight Standards District Office/certificate holding district office. (j) Additional Information For more information about this AD, contact Alexei Marqueen, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7178; email: Alexei.T.Marqueen@faa.gov. (k) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference (IBR) of the service information listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this service information as applicable to do the actions required by this AD, unless the AD specifies otherwise. (i) General Electric GE90-100 Service Bulletin 72-0914, dated January 25, 2023. (ii) [Reserved] (3) For service information identified in this AD, contact General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; phone: (513) 552-3272; email: aviation.fleetsupport@ge.com; website: ge.com. (4) You may view this service information at FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call (817) 222-5110. (5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit: www.archives.gov/federal-register/cfr/ibr-locations or email: fr.inspection@nara.gov. Issued on January 2, 2024. Caitlin Locke, Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2024-01166 Filed 1-22-24; 8:45 am]BILLING CODE 4910-13-P