What was found
IN-FLIGHT, CRUISE SETTING, ENGINE RPM DROPPED TO ZERO, PROPELLER ROTATED 2-3 TIMES AFTER RPM GAUGE READ ZERO. PILOT EXECUTED EMERGENCY LANDING. UPON ENGINE TEAR-DOWN, FOUND CRANKSHAFT BROKEN AT FORWARD CHEEK OF NR 2 MAIN BEARING JOURNAL. SUSPECT DEFECT (SCRATCH, NICK) STARTED IN JOURNAL RADIUS WHERE NR 2 CYLINDER CONNECTING ROD CONTACTED RADIUS POINT. SUBMITTER RECOMMENDS PRECAUTIONS TO BE TAKEN AT ENGINE OVERHAUL TO PRECLUDE EXCESSIVE MOVEMENT OF CONNECTING RODS AGAINST CRANKSHAFT THROWS AT DISASSEMBLY/REASSEMBLY.