The airplane took off on a cross country flight under visual flight rules to return to its home airport. While enroute, the pilot opened his VFR flight plan via radio with flight service. This was the last contact with the pilot. A ground witness who lives in the desert near the accident site stated that he heard a noise like an engine cutting out followed by noise resembling a car door slamming. A search was initiated for the airplane when it became overdue. The airplane wreckage and the fatally injured pilot and passengers were found the next day. The airplane struck the ground in a right wing low, stall spin attitude. All the wreckage was located in the immediate vicinity of the point of ground impact. The pilot obtained his private pilot airman certificate ten months prior to the accident and had logged approximately 85 flying hours in the same type airplane. There were no malfunctions or failures found with the engine.