It's kind of/sort of irrelevant how old the aircraft is. Guaranteed at that age the engine has been swapped out several times, and the fan blades have probably been swapped out of the engine too. If this is in fact a case of fan blade failure and not the inner stage turbine seal like we first speculated, the question will then become how many hours/cycles were on the engine and/or the blades and was United meeting inspection requirements on the blades, especially given the history of component failure.Well it sounds like this isn't exactly a new thing and the FAA may have been looking the other way. Also that plane is 27 years old. I can only imagine how many hours it has on it.