Flight History
On September 13, 2020, at 1432 central daylight time, a Cessna 172, N8488L, was destroyed in an accident near Cottage Grove, Minnesota. The flight instructor and two passengers were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the operator, the accident flight was a discovery flight arranged by the passenger for his girlfriend. The male passenger was seated in the right rear seat, the female passenger in the left front seat, and the flight instructor in the right front seat.
Automatic Dependent Surveillance-Broadcast (ADS-B) data indicated the airplane departed about 1428, proceeded southbound, crossed the Mississippi River, and turned to a southeast heading. The last return at 1432 placed the airplane over Lower Grey Cloud Island at about 1,900 ft and 101 mph. The flight profile showed a sharp descent followed by a sharp ascent, then a steep descent until impact. An aircraft performance study based on ADS-B data indicated a loss of over 1,000 ft in seven seconds, a descent rate exceeding 8,000 ft per minute before impact. A Go-Pro video from another pilot inbound to the departure airport captured the accident airplane descending. Eagles or geese were seen in the area, but no evidence indicated a collision with birds.
Wreckage and Impact Information
The wreckage was located in 70-foot-deep water and examined at a secure facility after recovery. All control cables failed at or near their cockpit connections, consistent with overload. Cables were traced from the cabin area to their respective flight control surfaces. Both wings displayed accordion-type compression damage aft to the main spar, consistent with high-speed impact. The left horizontal stabilizer had more impact damage than the right. The vertical stabilizer was impact damaged but straight, and the anticollision light on the tail was intact, indicating the airplane was upright on impact. Damaged propeller blades were bent aft into the engine compartment. Engine examination revealed no anomalies that would have precluded normal operation.
Medical and Pathological Information
The Ramsey County Medical Examiner performed the flight instructor's autopsy, listing cause of death as multiple traumatic injuries due to aircraft accident, with manner of death accidental. The FAA Forensic Sciences Laboratory identified ethanol at 0.051 g/dL in cavity blood but did not detect ethanol in urine.