Mooney M20J — Moose Lake, MN

What happened

The instrument rated private pilot departed into a snowstorm at the time of the accident. The pilot had just received a weather briefing and an instrument flight rules clearance. One witness heard the airplane take off from the non-towered airport toward the north and turn west before the sound of the engine stopped abruptly. A search was initiated after the pilot did not contact air traffic control. The airplane was found partially submerged in a river the next morning.

Weather observations around the time of the accident depicted gusty wind out of the north, low clouds, and light snow. Several witnesses in the area reported large snowflakes and an accumulation of 1.5 to 2 inches within an hour. The airplane was parked outside on the day of the accident. A witness at the airport was unaware of any tools that the pilot had access to clear snow or ice from the airplane before the flight. Investigators were unable to determine how much snow may have accumulated on the airplane before the flight or if the pilot removed any wing contamination before he took off.

The airplane came to rest near the west bank of the river in about 2 to 4 ft of water. The engine and propeller were imbedded in the mud and silt on the bank of the river and the tail was extended into the air. Signatures on the leading edge of both wings and at the fuselage were consistent with a nose low, wings level attitude at the time of impact. An examination of the airframe, engine, and related systems revealed no anomalies that would have precluded normal operations.

From the toxicology results, it appears that the pilot had taken the prescription medication clonazepam. The concentration of clonazepam in cavity blood was below therapeutic levels. The inactive metabolite, 7-amino-clonazepam was also detected at low concentrations, suggesting the use of the medication occurred several days prior to the accident. Thus, it is unlikely that the pilot’s use of clonazepam was a factor in the accident.

Based upon the statement from the witness, the prevailing wind at the time of the accident, and the location of the wreckage, the pilot likely departed from the north/south runway. It is most likely that the pilot lost control of the airplane after entering the snowstorm. The reason for the loss of control could not be determined with the available information.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.