What happened
On June 13, 1997, an SA-360C helicopter, registration OH-HTR, was performing a fertilizer spreading mission in Siilinjärvi. The pilot was operating the aircraft to transport a 900 kg fertilizer tank suspended from an external cargo hook.
During the takeoff phase, the leg of the fertilizer tank struck the ground approximately eight meters from the departure point, causing a noticeable jolt in the cockpit. While the pilot continued the takeoff using maximum power to increase airspeed, the suspended load swung significantly, eventually striking a row of bushes. The impact caused a sharp nose-down movement. Although the pilot attempted to increase power and released the load, the helicopter could not maintain altitude and descended into terrain containing trees and bushes. The main rotor blades struck two birch trees and various treetops, rendering the blades unserviceable. The impact also caused damage to the leading edge of the horizontal stabilizer. There were no injuries to the pilot.
The investigation
The investigation examined several factors affecting the aircraft's performance, including the environmental conditions, the pilot's recent flight history, and the accuracy of the loading equipment. Investigators analyzed the takeoff sequence, the impact of the terrain, and the lack of wind indicators at the temporary landing site. The investigation also reviewed the regulatory status of the pilot's agricultural flight qualification and the oversight of the training flight.