A fractured bracket caused an UPS cargo plane to crash in Louisville last November, killing 15 people, according to investigators. The engine detached during takeoff after a bearing assembly failed inside the bracket, sending the McDonnell-Douglas MD-11 skidding off the runway.

Investigators found that Boeing had issued service bulletins over a decade ago warning about the bearing problem, yet maintenance crews remained unaware of the risks. The company never classified the bearing as a critical safety component, and the FAA didn't require operators to replace it proactively.

The hearing revealed that mechanics at ST Engineering, the maintenance contractor, had never seen Boeing's service letters. Even UPS's own maintenance representative admitted ignorance about the bearing warnings until after the crash. Three other MD-11 aircraft were later found with similar bearing cracks during mandatory inspections.

This echoes the 1979 American Airlines Flight 191 disaster, where a DC-10 lost its left engine due to structural failure. The parallel raises serious questions about aviation safety protocols and whether manufacturers adequately communicate critical maintenance concerns to operators.