Airworthiness Directive · Amendment 39-19132 · Turbine section
General Electric Company Turbofan Engines
This AD applies to General Electric Company (GE) GEnx-1B64/P2, -1B67/P2, -1B70/P2, -1B70/75/P2, -1B70C/P2, and -1B74/75/P2 turbofan engines, with a high-pressure turbine (HPT) stage 1 blade retainer, part number (P/N) 2445M91P01 or 2383M99P02, with a serial number listed in Planning Information, Paragraph 1.A., of GE GEnx-1B Service Bulletin (SB) 72-0326 R02, revised August 16, 2017.
We are adopting a new airworthiness directive (AD) for certain General Electric Company (GE) GEnx-1B64/P2, -1B67/P2, -1B70/P2, -1B70/ 75/P2, -1B70C/P2, and -1B74/75/P2 turbofan engines. This AD was prompted by a report of the failure of the high-pressure turbine (HPT) stage 1 blade retainer and subsequent in-flight shutdown of the engine. This AD requires inspection of the HPT stage 1 blade retainer. We are issuing this AD to address the unsafe condition on these products.
(1) At the next piece-part exposure of the HPT stage 1 blade retainer after the effective date of this AD, perform a one-time inspection of the HPT stage 1 blade retainer in accordance with the Accomplishment Instructions, paragraph 3.A.(1), in GE GEnx-1B SB 72-0326 R02, revised August 16, 2017.
(2) If any cracks are found in the HPT stage 1 blade retainer, or the retainer does not meet the dimensional criteria found in the Accomplishment Instructions, Paragraph 3.A.(1), in GEnx-1B SB 72-0326 R02, revised August 16, 2017, replace the HPT stage 1 blade retainer with a part eligible for installation.
For the purpose of this AD, “piece-part exposure” is defined as when the part is completely disassembled.
