The National Transportation Safety Board says Boeing warned plane owners in 2011 about a flaw in the part that failed and contributed to the engine flying off a UPS plane before it crashed and killed 15 in November but at that point the plane manufacturer didn’t believe it threatened safety.
All the freight carriers are using decommissioned passenger planes, not exactly surprising. That said, the FAA should be holding them to better specs even though they’re not carrying people aside from the flight crew anymore.