What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
(-23) A/c at flight level 27 when the pilot experienced a sudden loss of manifold pressure. A landing was made at the Cedar City airport without incident. Maintenance found that the turbocharger had failed. The unit was sent to the "firewall forward" repair station (PP5R) for teardown. Inspection revealed that the shaft had broken off at the turbine wheel friction weld point and displayed evidence of foreign object damage to the turbine blades. This damage created excessive vibration in the shaft. Suspecting a piece of broken off exhaust valve passing through the turbine, firewall notified the owner and maintenance activity in cdc of the FOD damage to the blades. They requested that a compression test be performed on the engine cylinders to test the broken valve theory. This was accomplished satisfactorily.
As the FAA filed it
(-23) A/C AT FLIGHT LEVEL 27 WHEN THE PILOT EXPERIENCED A SUDDEN LOSS OF MANIFOLD PRESSURE. A LANDING WAS MADE AT THE CEDAR CITY AIRPORT WITHOUT INCIDENT. MAINTENANCE FOUND THAT THE TURBOCHARGER HAD FAILED. THE UNIT WAS SENT TO THE "FIREWALL FORWARD" REPAIR STATION (PP5R) FOR TEARDOWN. INSPECTION REVEALED THAT THE SHAFT HAD BROKEN OFF AT THE TURBINE WHEEL FRICTION WELD POINT AND DISPLAYED EVIDENCE OF FOREIGN OBJECT DAMAGE TO THE TURBINE BLADES. THIS DAMAGE CREATED EXCESSIVE VIBRATION IN THE SHAFT. SUSPECTING A PIECE OF BROKEN OFF EXHAUST VALVE PASSING THROUGH THE TURBINE, FIREWALL NOTIFIED THE OWNER AND MAINTENANCE ACTIVITY IN CDC OF THE FOD DAMAGE TO THE BLADES. THEY REQUESTED THAT A COMPRESSION TEST BE PERFORMED ON THE ENGINE CYLINDERS TO TEST THE BROKEN VALVE THEORY. THIS WAS ACCOMPLISHED SATISFACTORILY.