What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
During a flight from lax to kbxx at an approximate altitude of 5000 ft in a slow decent for phoenix engine RPM indicated 3000. At which time the airspeed began to decay. The pilot indicated he brought back the manifold pressure and propeller lever as he diagnosed the problem. Approximately 45 seconds into the event the engine and propeller stopped and a small amount of smoke appeared in the cockpit. Pilot could not make nearest airport and landed on rural road with no further incident.
Upon arrival to review aircraft, noted engine and propeller were already off aircraft. Found #4 connecting rod protruding through engine case. Noted crank seal was not seated in proper location. Could not positively identify cause of failure, due to aircraft propeller and engine being removed and partially disassembled and no tear down of engine being conducted/authorized by owner.
As the FAA filed it
DURING A FLIGHT FROM LAX TO KBXX AT AN APPROXIMATE ALTITUDE OF 5000 FT IN A SLOW DECENT FOR PHOENIX ENGINE RPM INDICATED 3000. AT WHICH TIME THE AIRSPEED BEGAN TO DECAY. THE PILOT INDICATED HE BROUGHT BACK THE MANIFOLD PRESSURE AND PROPELLER LEVER AS HE DIAGNOSED THE PROBLEM. APPROXIMATELY 45 SECONDS INTO THE EVENT THE ENGINE AND PROPELLER STOPPED AND A SMALL AMOUNT OF SMOKE APPEARED IN THE COCKPIT. PILOT COULD NOT MAKE NEAREST AIRPORT AND LANDED ON RURAL ROAD WITH NO FURTHER INCIDENT.
UPON ARRIVAL TO REVIEW AIRCRAFT, NOTED ENGINE AND PROPELLER WERE ALREADY OFF AIRCRAFT. FOUND #4 CONNECTING ROD PROTRUDING THROUGH ENGINE CASE. NOTED CRANK SEAL WAS NOT SEATED IN PROPER LOCATION. COULD NOT POSITIVELY IDENTIFY CAUSE OF FAILURE, DUE TO AIRCRAFT PROPELLER AND ENGINE BEING REMOVED AND PARTIALLY DISASSEMBLED AND NO TEAR DOWN OF ENGINE BEING CONDUCTED/AUTHORIZED BY OWNER.