Accident Details
Approximately seven minutes after takeoff, while climbing, the pilot observed a significant drop in oil pressure. Shortly after, a noise was heard from the engine. The pilot initiated a diversion back toward the airport. The engine began running rough and subsequently failed. The aircraft made an emergency landing in a dry river wash. During the landing, the aircraft impacted terrain and caught fire.
Occupant Injuries
One occupant sustained fatal injuries during the accident. The pilot, who suffered thermal injuries, and one passenger succumbed to their injuries one day later.
Investigation
Examination of the aircraft revealed evidence of oil loss and oil exhaustion. A heavy coating of oil was found on the belly of the aircraft. Investigators found that a B-nut fitting on an oil line running from the engine to the right oil cooler had backed off the nipple fitting on the engine. This oil supply line was one that was typically removed during oil changes to facilitate removal of the oil filter and to drain the oil cooler.
Further investigation revealed that the pilot had performed his own oil and oil filter changes. He had changed the oil and filter two days before the accident.