As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, EXPERIENCED THE RIGHT ENGINE RPM FLUCTUATED. ADVANCED THROTTLE & NO POWER CHANGE OR CHANGE IN MANIFOLD PRESSURE, DREW ENGINE BACK TO IDLE & CHT REDUCED. FOLLOWED EMERGENCY PROCEDURES AND SHUTDOWN THE ENGINE. DECLARED AN EMERGENCY, RETURNED TO DEPARTURE.AND LANDED WITHOUT INCIDENT. MAINTENANCE INSPECTED THE ENGINE AND REMOVED THE OIL FILTER AND INSPECTED FOR CONTAMINATION. THE RESULTS NOTED WERE NON-FERRIS MATERIAL & COINCIDE WITH A TURBO-CHARGER BEARING FAILURE. REMOVED AND REPLACED THE TURBO CHARGER WITH OVERHAULED UNIT. RETURNED TO SERVICE