RE: Southwest Airline Flight #1380 engine failure.
Turbofan engineer anon here. This is not the first time a CFM56-7B22 fan rotor has violently disassembled itself. FAA proposed a new rule in Aug17. Considering the number of engines out there and how astoundingly reliable they are, it takes quite a while to inspect all the blades when an engine comes in for a shop visit. No idea if the incident engine has been inspected or how many cycles are on the blades.