Mr Heflin; So wrong on so many levels. I suspect you've never been involved in aircraft maintenance and witnessed the inspection complexity and the hundreds of people who are involved over a long period of time. I was a C-130 USAF crew chief for several years and a flight engineer for over 20 years; including the civil commercial model; L100. The flight engineer inspects the props prior to flight standing on the ground looking up at the blades for obvious defects. Corrosion is not an obvious defect. Its not like the obvious, visual corrosion on your boat . It's hidden and requires Non Destruction Testing to find it. The major player here is the depot. They have the equipment and the trained NDT inspectors to find corrosion. They are paid to perform proper depot level inspections. These depot inspections are considerably more complex than what can be performed at the squadron field level.
When I first learned of the crash I assumed a wing had failed, that's a well known issue. A blade breaking off is rare indeed. I remember once that it happened on an A model about 100 years ago but did not cause a crash.
I pray for the lost lives.