What was found
DURING DESCENT, FLT CREW OBSERVED FLUCTUATING FUEL FLOW ON RT ENG FOLLOWED BY VIBRATION AND NOISE. CREW REDUCED POWER SETTING TO IDLE AND CONTINUED FLT. DURING FINAL APROACH, OIL PRESSURE BEGAN TO FLUCTUATE AND LOW OIL PRESSURE CAUTION LIGHT ILLUMINATED. PILOT COMMANDED A SHUT-DOWN AND LANDED ACFT WITHOUT FURTHER INCIDENCE. UNABLE TO ROTATE EITHER THE LP OR HP SPOOLS. EXAMINATION OF INLET AREA SHOWED NO EVIDENCE OF FOREIGN OBJECT INGESTION. METAL CONTAMINATION FND IN OIL TANK, XSFER GEARBOX AND OIL FILTER, FILTER BYPASS BUTTON WAS NOT OUT. UNABLE TO DISASSEMBLE OIL PUMP DUE TO INTERNAL DAMAGE. ENG IN-FLT SHUTDOWN CAUSED BY FAILURE OF NR 4 BEARING AND SUBSEQUENT INTERNAL DOMESTIC OBJECT DAMAGE TO ENGINE.