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

The FAA is adopting a new 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 6089T89P01. This AD requires initial and repetitive visual and eddy current inspections of those disks. This AD also allows as optional terminating action to the repetitive inspections, replacement of those SN disks. This AD also requires replacement of certain stage 5 and stage 6 LPT disks. This AD results from a report of a stage 5 LPT disk that failed due to cracking from low-cycle-fatigue (LCF) during factory testing. 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.