Accident
While cruising at 8,500 feet mean sea level, the pilot noticed a loss of all oil pressure. The pilot secured the engine, lowered the landing gear and wing flaps, and declared an emergency, stating he would attempt an engine-out landing at Harris Ranch Airport. While descending through 1,000 feet mean sea level, the pilot reported that he could not reach the airport and retracted the flaps. The aircraft nosed over in a soft plowed field one-quarter mile short of the runway.
Investigation
Examination of the aircraft revealed evidence of an oil leak in the engine, and the bottom of the aircraft was covered with oil. The engine contained no oil. A hole was found in the crankcase, caused by the failure of the number six connecting rod. The other connecting rods were overheated. The oil filter adapter was safety-wired but was very loose; its internal and external threads were badly worn.
Findings
The loss of engine power was attributed to a total loss of oil due to a hole in the crankcase resulting from the failure of the number six connecting rod. The loose oil filter adapter with worn threads may have been a contributing factor, though the primary failure was the connecting rod.