Airworthiness Directive · Amendment 39-21878 · Turbine section
General Electric Company Turbofan Engines
This AD applies to General Electric Company (GE) CF34-8C5, CF34-8C5B1, CF34-8E2, CF34-8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E6, and CF34-8E6A1 model turbofan engines with an installed high-pressure turbine (HPT) rotor stage 1 disk, part number (P/N) 4125T22P04, and a serial number (S/N) listed in Figure 1 or Figure 2 to paragraph (c) of this AD.
The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) CF34-8C and CF34-8E model turbofan engines. This AD was prompted by a report of a quality escape during the manufacturing of a high-pressure turbine (HPT) rotor stage 1 disk. This AD requires removing the HPT rotor stage 1 disk from service and replacing the HPT rotor stage 1 disk with a part eligible for installation. The FAA is issuing this AD to address the unsafe condition on these products.
For all affected engines, at the next engine shop visit or before the HPT rotor stage 1 disk accumulates 7,600 cycles since new, whichever occurs first after the effective date of this AD, remove the HPT rotor stage 1 disk from service and replace with a part eligible for installation.
For the purpose of this AD:
(1) An “engine shop visit” is the induction of an engine into the shop for maintenance involving the separation of pairs of major mating engine flanges, except that the separation of engine flanges solely for the purposes of transportation without subsequent engine maintenance does not constitute an engine shop visit.
(2) A “part eligible for installation” is an HPT rotor stage 1 disk that is not listed in Figure 1 or Figure 2 to paragraph (c) of this AD or an HPT rotor stage 1 disk that has been repaired using an FAA-approved repair.
Note 1 to paragraph (h)(2): Guidance for repairing the HPT rotor stage 1 disk can be found in GE Repair Document RD #150-1811-P1, dated March 17, 2020.
