What happened
On September 23, 2012, at approximately 12:40, an FK 9 Mark IV ultralight aircraft crashed in the Kaldoaivi wilderness near Petsikko, Finland. The aircraft, which was equipped with amphibious floats, had departed from Lake Saarijärvi in Utsjoki about 30 minutes prior to the accident. The flight's objective was to fly along the boundaries of the Kaldoaivi reindeer herding cooperative to observe reindeer and attempt to herd them toward a collection point. The crew also intended to make a landing at Lake Juokkarjärvi.
Following the aircraft's failure to arrive at its intended destination or return to Utsjoki, a report of the missing aircraft was made to the Aeronautical Rescue Coordination Centre (ARCC) at 19:50. Search operations located the wreckage the following morning at approximately 09:30. The aircraft had struck the ground at a steep angle with its wings nearly horizontal, triggering a severe fire that completely destroyed the airframe. Both the pilot and the passenger sustained fatal injuries.
The investigation
Investigators examined the wreckage and recovered all peripheral components of the aircraft. While the engine was found either idling or stopped, and no specific mechanical failure was identified during technical testing, the intense fire prevented investigators from entirely ruling out a technical malfunction. GPS data retrieved from the aircraft revealed that the pilot had been performing low-altitude maneuvers at low airspeeds prior to the impact.
Regarding the pilot, investigators noted that the pilot's license had expired in 2011. While the pilot possessed sufficient general flight experience, they lacked specific training or experience for low-level flight and the performance of aerial herding, which is classified as aerial work under aviation regulations.
Findings
- The primary cause of the accident was an aerodynamic stall occurring during low-speed flight.
- The aircraft was significantly overweight, with an estimated takeoff weight of 612 kg, far exceeding the maximum allowable takeoff weight of 495 kg for this type of two-seat ultralight seaplane.
- The excessive weight increased the aircraft's stall speed, making the low-speed maneuvers more hazardous.
- The pilot was engaged in unauthorized aerial work (reindeer herding) without the required permits.
- The aircraft's useful load capacity was also compromised, recorded at only 123 kg despite a regulatory requirement of 175 kg.