Pilot Debrief

Cessna 172 near Cottage Grove, MN — 2020-09-13

Final reportCEN20LA392
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Date
2020-09-13
Location
Cottage Grove, MN, USA
Airport
SGS
Aircraft
Cessna 172
Registration
N8488L
Category
Airplane
Highest injury
Fatal
Fatalities
3
Phase of flight
Descent

Probable cause

A steep descent and impact with terrain for reasons that could not be determined based on the available information.

NTSB narrative

The accident flight was a “discovery flight” arranged by the rear seat passenger for his girlfriend, the front seat passenger. A flight instructor was seated in the right front seat. Flight track information revealed that, about four minutes after departure at an altitude of about 1,900 ft, the airplane entered a steep descent that continued until water contact. The airplane was destroyed when it impacted the water. Examination of the airplane revealed no evidence of mechanical anomalies that would have precluded normal operation, and no evidence of a bird strike. Visual meteorological conditions were present in the area at the time of the accident. Available medical information provided no evidence that the CFI had any medical condition, substance use, or toxic exposure that contributed to the accident. Based on the absence of detected ethanol in the CFI’s urine, it is likely that ethanol detected in his cavity blood was from sources other than ingestion. Given the available information, the reason for the airplane’s impact with terrain could not be determined.

Analysis

Primary failure mode
Loss of control
First missed decision gate
Pilot could have aborted the flight after the sharp descent began.

NTSB coding

Evidence available

  • Video
  • Photos
  • 14 docket documents
View NTSB final reportView NTSB docket

Docket documents14

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