What happened
During an arrival procedure, the pilot of a Beech TC-45J (modified as a Hamilton Turboliner) reported encountering moderate icing at an altitude of 4,000 feet. The flight was performing a localizer-only approach toward runway 35. Air traffic control observers noted the aircraft emerging from cloud cover near the approach end of the runway. At this stage, the pilot communicated intentions to execute a left base turn for runway 35 and confirmed the runway was in sight.
As the aircraft began the turn, it transitioned into a steep nose-down attitude. The plane subsequently struck a railroad yard while maintaining a relatively level orientation with its landing gear extended and flaps retracted; however, the descent angle at impact was estimated at approximately 30 degrees. The impact and subsequent ground fire resulted in the total destruction of the aircraft. There were no signs of mechanical failure or malfunction prior to the crash. The sole occupant of the aircraft, the pilot, was killed.
Findings
Investigations into the accident identified several contributing environmental factors, including flight into known adverse weather involving rain, fog, and icing conditions. The aircraft was operating below established approach and landing minimums. Additionally, the investigation concluded that the loss of control was linked to an inadvertent stall caused by inadequate airspeed during a circling maneuver.