What happened
The pilot received two weather briefings prior to departure. The initial briefing focused heavily on identifying an alternate airport due to forecast conditions including Instrument Meteorological Conditions (IMC), low ceilings, reduced visibility, light snow, fog, and possible freezing drizzle. The aircraft was not certificated for flight in known icing conditions.
During the arrival phase, the plane entered an overcast layer at 3500 feet MSL. Two minutes later, the pilot reported encountering freezing precipitation. The first approach was abandoned near the Final Approach Fix (FAF) or outer marker after the pilot flew through the localizer course line and ended up approximately one-half mile to the right of the intended path.
The pilot was vectored for another Instrument Landing System (ILS) approach. While inbound, he was informed that approach control had received a low altitude alert. He was reminded that his altitude should be 2600 feet until reaching the FAF; however, he reached only 2400 feet. His airspeed was much higher than normal while descending from the FAF. The plane struck a building and burned about one-third mile northeast of the end of runway 18.
The investigation
The investigation examined the aircraft's certification status regarding icing conditions and the pilot's adherence to altitude restrictions during the instrument approach. It noted the discrepancy between the assigned altitude and the actual altitude reached by the pilot.
Findings
Contributing factors included the freezing precipitation encountered by an aircraft not certificated for such conditions, the pilot's failure to maintain the assigned altitude of 2600 feet, and excessive airspeed during descent. The pilot deviated from the localizer course on the first approach and failed to correct altitude on the second attempt despite alerts.
Safety message
Pilots must ensure their aircraft is certificated for known icing conditions before entering such environments. Strict adherence to assigned altitudes and airspeed restrictions during instrument approaches is critical for terrain clearance.