FAA To Issue Airworthiness Directive On Certain Continental Engines - AVweb

How does this happen? Was a new person assigned to place snap rings, who did not know how to do it properly? Was the snap ring plier worn out? Were a lot of the crankshaft receiving grooves not machined properly? Was this employee sabotage?

Continental has been building these engines for umpteen years. Where is the Root Cause Analysis of what happened to this lot? The single point of failure has been known about since a Battle was lost due to the lack of a Horse Shoe Nail.