Airworthiness Directive · Amendment 39-21933 · Turbine section
General Electric Company Turbofan Engines
This AD applies to General Electric Company (GE) GEnx-1B64, GEnx-1B64/P1, GEnx-1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/P2, GEnx-1B70, GEnx-1B70/75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-1B70/P2, GEnx-1B70C/P1, GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/75/P2, GEnx-1B76/P2, GEnx-1B76A/P2, GEnx-2B67, GEnx-2B67B, and GEnx-2B67/P model turbofan engines with a compressor discharge pressure (CDP) bolted joint assembled or reassembled with the 11C4525P01 torque fixture or assembled with the 11C4629P01 torque wrench.
The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) GEnx-1B and GEnx-2B model turbofan engines. This AD was prompted by the manufacturer's report of two findings of sheared compressor discharge pressure (CDP) bolts during engine shop visits. This AD requires initial and repetitive inspections of the CDP bolted joint and, depending on the findings, a piece part inspection of the stages 6-10 compressor rotor spool, CDP seal, and high-pressure turbine (HPT) rotor stage 1 disk. As a terminating action, this AD requires operators to reassemble the CDP bolted joint using a specific torque wrench. The FAA is issuing this AD to address the unsafe condition on these products.
(1) At the next engine shop visit after the effective date of this AD, perform an inspection of the CDP bolted joint for fractured or missing material using the Accomplishment Instructions, paragraph 3.A.(2) of GE GEnx-1B Service Bulletin (SB) 72-0495 R00, dated May 11, 2021 (GEnx-1B SB 72-0495) (for GEnx-1B models) or Accomplishment Instructions, paragraph 3.A.(2) of GE GEnx-2B SB 72-0433 R00, dated May 11, 2021, (GEnx-2B SB 72-0433) (for GEnx-2B models).
(2) Repeat the inspection required by paragraph (g)(1) of this AD at every engine shop visit.
(3) If a fractured or missing bolt or nut is found during any inspection required by paragraph (g)(1) or (2) of this AD, before further flight, perform piece part inspections of the stages 6-10 compressor rotor spool, CDP seal, and high-pressure turbine rotor stage 1 disk in accordance with the Instructions for Continued Airworthiness.
As terminating action to the repetitive inspections required by paragraph (g)(2) of this AD, reassemble the CDP bolted joint using the 11C4888P01 torque wrench, in accordance with the Accomplishment Instructions, paragraph 3.B.(1) of GEnx-1B SB 72-0495 (for GEnx-1B models) or the Accomplishment Instructions, paragraph 3.B.(1) of GEnx-2B SB 72-0433 (for GEnx-2B models).
For the purpose of this AD, an “engine shop visit” is the induction of an engine into the shop for maintenance involving a module exposure in which the mid fan shaft removal exposes the CDP bolted joint.
