A witness reported that he saw the airplane takeoff from the airpark and fly a left traffic pattern. The airplane disappeared behind a tree line after lining up on a pipeline easement northeast of the airport. The witness then reported a bright flash from a power line, and he responded to the accident scene. He observed the airplane resting inverted in the field. The airplane sustained substantial damage to both wings and the forward fuselage. A Federal Aviation Administration (FAA) inspector responded to the accident site. The inspector reported that the airplane struck a set of power lines and crashed in a pipeline field about seven-tenths of a mile from the airpark. The owner of the property adjacent to the field told the inspector that he witnessed the airplane hit the power lines and that the airplane appeared to be attempting to land in the field. The witness reported that since the accident he has spoken with the pilot on multiple occasions and the pilot has no memory of the crash or the events leading to the accident. However, in his statement to the FAA inspector, the witness reported the pilot telling him several times that he was on final approach to the runway when he hit the power lines.