Event
During cruise at flight level 370, the flight crew heard a loud noise resembling an explosion. The number one engine subsequently lost power, and the airplane began to experience vibrations. The crew shut down the affected engine and continued to Newark, where an uneventful landing was performed using the remaining two engines.
Investigation
Post-flight inspection revealed an engine turbine blade lodged in the airplane's vertical stabilizer. A teardown examination of the engine indicated thermal distress on the first stage turbine blades. This thermal distress caused a degradation of material properties, leading to fractures in the blades. The specific cause of the thermal distress could not be determined during the investigation.
Findings
The engine teardown showed that thermal distress to the first stage turbine blades resulted in a degradation of material properties, which in turn caused blade fractures. The origin of the thermal distress remains unidentified.