As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT NR 397 - DEN - THE NR 2 ENGINE SUDDENLY SPOOLED DOWN WITH VIBRATION, IN FLIGHT AT 31,000 FEET. THE AIRCRAFT WAS DIVERTED TO DEN WHERE IT LANDED WITHOUT INCIDENT. THE NR 2 ENGINE WAS REMOVED AND REPLACED. DISASSEMBLY OF THE ENGINE REVEALED NR 4 BEARING FAILURE AS THE PRIMARY CAUSE OF THE ENGINE IN FLIGHT SPOOL DOWN. (M)