How often are the turbines in the hot section of the jet engines replaced due to deteriorated TBC? or just how often are they replaced? lets say for CFM56-7
So this article, says that the average brand new CFM56-7 will go 18,000 cycles (i.e. flights) before its first shop visit. You can't replace the turbine blade on-wing, only in the overhaul shop. So we could say that the blades would last at least 18,000 flights, potentially longer.