As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CRUISE FLIGHT, THE PILOTS NOTED A LOSS OF ENGINE POWER, ACCOMPANIED BY ABNORMAL ENGINE SOUNDS AND A BURNING ODOR. THEY DIVERTED TO ANOTHER AIRPORT. VISUAL INSPECTION OF THE ENGINE REVEALED THE NR 1 CYLINDER HEAD WAS IN THE PROCESS OF SEPARATING FROM THE BARREL AND ESCAPING COMBUSTION GASSES HAD BURNED HOLES IN THE CYLINDER BAFFLE AND ADJACENT COMPONENTS. THE ENGINE HAD LAST UNDERGONE A DETAILED INSPECTION 7.3 HOURS PRIOR; A COMPRESSION TEST WAS 70/80 AND NO DEFECTS WERE FOUND AT THAT TIME. THE CYLINDER HEAD CASTING NR WAS C-03354.