What was found
AFTER LANDING, PILOT REPORTED SUBSTANTIAL OIL LEAK. FOUND STARTER DRIVE/ SCAVENGE PUMP ASSY PN R-642085A17 HAD A SHEARED DRIVE SHAFT. THIS CAUSED EXCESSIVE OIL TO GO TO AIR OIL SEPERATOR AND OVERBOARD DUE TO SEPERATOR COULD NOT RETURN THE VOLUME OF OIL COMING TO IT TO RETURN TO ENGINE SUMP. DISCOVERED SHEARED SHAFT AT REMOVAL OF SCAVENGE PUMP STARTER DRIVE ASSY. REPLACED AND FUNCTIONAL CHECKS GOOD. STARTER DRIVE HAD 101.1 TSOH