What was found
(CAN) WHEN MAINTENANCE REPORTED FOR WORK A POOL OF OIL WAS FOUND UNDER THE ENGINE. TROUBLESHOOTING RESULTED IN FINDING A STUCK CHECK VALVE AND METAL PARTICLES IN THE OIL FILTER. THE ENGINE WAS REMOVED AND RETURNED TO A REPAIR FACILITY WHO REPORTED THAT THE AGB DUPLEX BEARING HAD FAILED FOR REASONS UNKNOWN. THE DUPLEX BEARING THAT FAILED WAS A NEW PN 3112999-01 THAT BEEN INSTALLED IAW PWC SB 7329 AT THE LAST ENGINE OVERHAUL.