What happened
During an instructional flight, a flight instructor was training a second pilot on the specific procedures required for operating a ski-equipped aircraft on frozen surfaces. The session was intended to familiarize the trainee with landing and takeoff techniques on snow and ice.
While performing a touch-and-go maneuver on a frozen, snow-covered lake, the instructor took control of the aircraft to demonstrate a specific technique. After touching down on the eastern side of the lake, the instructor maintained the tail section in an elevated position while keeping the airspeed slightly below flying speed. This maneuver was performed to create visible tracks in the snow to assess the surface conditions.
As the aircraft reached the middle of the lake, the instructor applied full engine power to initiate a takeoff. However, the aircraft failed to gain enough altitude to clear rising, tree-covered terrain located at the far end of the lake. The impact with the trees caused substantial damage to the wings, fuselage, and empennage of the aircraft.
Findings
An examination of the aircraft following the accident showed no evidence of mechanical failures or anomalies prior to the event. The instructor noted that the area was experiencing occasional strong gusts of wind originating from the west during the flight.