Background
The pilot was cleared for an instrument approach to the airport. After exiting cloud cover, the pilot was observed circling at low altitude on a closed left downwind for runway 30.
Accident Sequence
Witnesses reported that during the turn from base to final, the aircraft established a very steep angle of bank while engine power was heard increasing. Subsequently, control was lost, and the airplane impacted the ground in an inverted, nose-low attitude. A post-impact fire consumed the aircraft. Both occupants were killed.
Weather and Light Conditions
At the airport, weather was reported as 900-foot overcast ceiling with 2 miles visibility in fog and haze with light mist. Official sunset occurred one minute prior to the impact.
Probable Cause
According to official findings, the probable cause of the accident was an inadvertent stall, with factors being the weather and the light conditions.