What happened
On July 3, 2007, an Eurocopter AS350 B3 helicopter, registration HB-ZGT, was performing a commercial hay transport mission in Sassi Grossi, Bodio. The operation involved moving hay bales from a loading site at Alp Monti di Faidal to a landing zone at a lower altitude.
During the eighth and final rotation of the day, the helicopter was in a descent phase to deposit the load. The cargo, secured in a net and suspended by a 20-meter long sling, was approximately three meters above the ground when it collided with a person on the ground. The impact caused serious injuries to the individual. The flight crew and a ground assistant attempted to issue warnings, but the collision occurred before the person could be moved from the danger zone.
The investigation
The investigation examined the operational procedures, the training of the ground crew, and the circumstances surrounding the presence of the third party at the landing site. It was established that while a ground assistant was present to manage the load and communicate with the pilot, the owner of the cargo was also present at the landing site. This individual had been engaged in tasks such as organizing straps and nets, though they were not officially part of the flight crew.
Findings
- The primary cause of the accident was the collision between the external load and a person who unexpectedly entered the danger zone.
- The individual involved had not been briefed on the potential hazards of the helicopter operations prior to the commencement of the transport.
- The ground assistant, who had been employed for approximately three months, was focused on transmitting altitude updates to the pilot via radio and noticed the approaching person only at the last moment.
- The pilot was focused on the final approach and also observed the person late in the sequence.
- The aircraft and its equipment, including the 20-meter sling, were functioning correctly with no technical failures identified.
- Weather conditions were clear with good visibility and did not contribute to the accident.