Airworthiness Directives; General Electric Company CF34-3A1 and -3B1 Series Turbofan Engines

The FAA is revising an existing airworthiness directive (AD) for General Electric Company (GE) CF34-3A1 and -3B1 series turbofan engines with certain serial numbers (SNs) of stage 5 low pressure turbine (LPT) disks, part number (P/N) 6078T92P01, and/or certain SNs of stage 6 LPT disks, P/N 6078T89P01. That AD currently requires initial and repetitive visual and eddy current inspections of those disks. That AD also allows as optional terminating action to the repetitive inspections, replacement of those SN disks. Also, that AD requires replacement of certain stage 5 and stage 6 LPT disks. This ad requires the same actions. This AD results from the discovery that an incorrect part number for stage 6 LPT disks was published in the existing AD and from the need to allow credit for actions completed per previous releases of Alert Service Bulletin CF34-AL S/B 72-A0173. We are issuing this AD to prevent LCF failure of stage 5 LPT disks and stage 6 LPT disks, which could lead to uncontained engine failure.