What was found
PILOTS REPORTED A MASSIVE ENGINE OIL LEAK FROM LH ENGINE DURING FLIGHT. THEY MADE A PRECAUTIONARY LANDING AND CALLED FOR MAINTENANCE. A TECH FOUND THE HEAD OF A SHEARED 12-POINT BOLT INSIDE THE COWLING. FURTHER INVESTIGATION FOUND THAT THE BOLT HEAD HAD COME FROM INSIDE THE CRANKCASE AROUND THE #2 PISTON. THE CRANKCASE HAS A HOLE IN THE BLOCK ROUGHLY 1" IN DIAMETER, WHICH WAS POURING OUT OIL. A PIECE OF THE BLOCK WAS ALSO FOUND IN THE COWLING. ENGINE MANUFACTURER BELIEVES IT TO BE FROM THE CRANKSHAFT BEARING. THE PILOTS REPORTED THAT THE ENGINE RAN NORMALLY AFTER THE OIL LEAK WAS NOTED.