What was found
(CAN) LEFT MAGNETO ADAPTER DRIVE BEARING SPINNING IN ACESSORY CASE. ENGINE CASE WAS DAMAGED BY SPINNING BEARING. ENGINE REMOVED FOR REPAIR, O/H. THE OPERATOR HAS HAD A NUMBER OF OTHER INCIDENTS OF MAGNETO DRIVE BEARING FAILURE. FAULT HAS BEEN DISCUSSED WITH ENGINE MFR AND O/H SHOPS. OPERATOR HAS REVEIWED MAGNETO INSTALLATION PROCEDURES WITH ALL MAINTENANCE STAFF.