Airworthiness Directives; General Electric Company CF34-3A1 Turbofan Engines
The FAA is adopting a new airworthiness directive (AD) for General Electric Company (GE) CF34-3A1 turbofan engines installed on Bombardier series Regional Jets with certain high pressure turbine (HPT) rotating components installed. This AD requires removal from service of certain HPT components prior to the parts exceeding their designated life limits. This AD results from the discovery that the manufacturer removed certain part numbers of HPT rotating components from the Life Limits section of the CF34 Engine Manual, SEI-756. The effect of this manual change was the removal of life limits from certain components that are eligible for installation in GE CF34-3A1 engines. We are issuing this AD to impose life limits on these HPT rotating components to prevent low cycle fatigue (LCF) cracking and failure of those components, which could result in uncontained engine failure and damage to the airplane.