What was found
AIRCRAFT EXPERIENCED A LOSS IN OIL QUANTITY IN THE RT ENGINE. DIVERTED TO YUL. OIL QUANTITY AT TOP OF DESCENT WAS ZERO WITH NORMAL TEMP/PRESSURE. ARRIVED WITH NO PROBLEMS. "ENG OIL FILTER R" BYPASS MESSAGE DISPLAYED AT TOP OF DESCENT; ENGINE CONTINUED TO OPERATE NORMALLY UNTIL DELIBERATELY SHUT DOWN ON THE GROUND. METAL WAS FOUND ON NR 3 BEARING MAGNETIC CHIP DETECTOR, ENGINE REMOVED. EXTENSIVE FRETTING WEAR BETWEEN NR 3 BEARING AND CARBON SEAL SEAT COMPONENTS, ESPECIALLY INNER RACE AND REAR SEAL SEAT. OIL WETTING & COKING WAS FOUND IN THE HIGH PRESSURE TURBINE T1 DISK, INDICATING OIL LOSS THROUGH THIS AREA.