What happened
On July 18, a seaplane was conducting training maneuvers on Lake Siljan as part of an Austrian Approved Training Organization (ATO) program. The flight, which included an instructor and two students, was intended to facilitate a student's first sea-based flight through a series of repeated take-offs and landings. While the flight was part of a training framework, the instructor had not yet completed the required annual refresher training for the flight school, leading the session to be conducted as a private flight.
The flight departed from Siljansnäs Airport under weather conditions characterized by good visibility, high cumulus clouds, and moderate, variable winds from the southwest. After completing several successful landings, the aircraft turned east-northeast over Sollerön island to attempt another landing. During this maneuver, the aircraft tipped forward and flipped over. The accident resulted in two fatalities, claiming the lives of both the instructor and the student.
The investigation
The Swedish Accident Investigation Authority (SHK) examined the circumstances surrounding the flight and the aircraft's configuration. Investigators determined that the aircraft was likely configured for water operations with the landing gear retracted at the time of the accident. The investigation found no evidence of any technical malfunctions or mechanical failures that could have contributed to the crash.
Findings
The investigation identified that the primary cause of the accident was that the flight was planned and executed with a level of difficulty that exceeded the instructor's current proficiency and the student's specific experience with seaplane operations. Because the instructor had not completed his annual training, his recent experience on the type was insufficient for the complexity of the mission.
Furthermore, the crew failed to perform a reconnaissance of the landing area prior to the attempt. This lack of preparation led to the landing being performed at a high speed, into a tailwind, and in sea conditions that were likely too rough for the aircraft's operational limitations.
Safety action
Following the investigation, a recommendation was issued to EASA to develop and distribute safety-promoting materials specifically targeting seaplane operations to inform relevant stakeholders of the risks involved.