What happened
The aircraft was operating under visual flight rules (VFR) along the shoreline of Lake Michigan when the pilot encountered a sudden decrease in ceiling height. Recognizing the deteriorating conditions, the pilot decided to execute a 180-degree maneuver to return to the departure airport.
During this turn, the aircraft entered a bank of fog. To avoid the reduced visibility, the pilot descended below the safe altitude. Inadvertently, the aircraft impacted the surface of Lake Michigan during this descent.
The investigation
The investigation focused on the sequence of events leading to the impact with the water. Examination of the flight path and weather conditions indicated that the pilot was operating in marginal visual meteorological conditions (MVFR) or lower without adequate situational awareness of the terrain and water surface below.
Findings
The primary factors contributing to the accident were the encounter with a fog bank during a turn and the subsequent uncontrolled descent into the lake. The pilot's decision to continue VFR flight into deteriorating weather conditions played a significant role in the outcome.
Deteriorating weather conditions led to the loss of visual reference, resulting in controlled flight into terrain (water).