Airworthiness Directive · Amendment 39-21267 · Turbine section
General Electric Company Turbofan Engines
This AD applies to all General Electric Company (GE) GEnx-1B64/P2, -1B67/P2, -1B70/P2, -1B70C/P2, -1B70/75/P2, -1B74/75/P2, -1B76/P2, -1B76A/P2, and GEnx-2B67/P model turbofan engines with:
(1) a high-pressure turbine (HPT) rotor stage 2 disk, part number (P/N) 2383M86P02, having one of the following serial numbers (S/Ns): TMT18D6T, TMT18D6U, TMT18JC4, TMT18NGC, TMT1985C, TMT3UA34, TMT3UA55, TMT4CT46, or TMT4CT47, installed; or
(2) a stages 6-10 compressor rotor spool,P/N 2628M56G01, S/N GWN10ECM, installed.
The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) GEnx-1B64/P2, -1B67/P2, -1B70/P2, -1B70C/P2, -1B70/75/P2, -1B74/75/P2, -1B76/P2, -1B76A/P2, and GEnx- 2B67/P model turbofan engines. This AD was prompted by the detection of melt-related freckles in the billet, which may reduce the life limits of certain high-pressure turbine (HPT) rotor stage 2 disks and a certain stages 6-10 compressor rotor spool. This AD requires the removal of certain HPT rotor stage 2 disk and the removal of a certain stages 6-10 compressor rotor spool before reaching their new life limits. The FAA is issuing this AD to address the unsafe condition on these products.
After the effective date of this AD, before the parts accumulate the cycles since new (CSN) threshold listed in Table 1 to paragraph (g) of this AD, remove the affected HPT rotor stage 2 disk and the stages 6-10 compressor rotor spool from service and replace with parts eligible for installation.
After the effective date of this AD, do not install the affected HPT rotor stage 2 disks or the stages 6-10 compressor rotor spool identified in Table 1 to paragraph (g) of this AD on an engine.
