What happened
On February 18, 2003, an Aerospatiale AS350 B2 helicopter, registration I-EQUR, was performing a repositioning flight for passenger transport services. The aircraft departed from Corvara in Badia, heading toward Riscone di Brunico to pick up tourists for a transfer to the Marmolada region.
As the pilot approached a meadow in front of a local hotel, the flight profile involved a 360-degree turn followed by a 180-degree turn while progressively descending. During the final phase of the approach, which was being executed in the direction opposite to the initial approach, the lower part of the vertical stabilizer struck the Brunico-Bolzano electrical power lines. The impact caused the lower vertical plane to detach and become entangled in the cables. The upper vertical plane and the tail rotor also detached from the airframe.
Following the sudden jerk, the pilot attempted to maintain control, but the loss of tail rotor surfaces caused the helicopter to yaw uncontrollably before crashing into the ground. The pilot, who sustained a minor head injury, multiple contusions, and spinal compression, managed to exit the wreckage after the impact forced the cabin door open. The pilot then successfully shut down the engine and secured the aircraft.
The investigation
The ANSV investigation focused on the visibility conditions and the pilot's approach maneuvers. Aerial photographic surveys conducted after the accident revealed that sunlight reflecting off the snow-covered ground, combined with tracks left by skis, significantly obscured the view of the power lines.
However, investigators noted that two electricity pylons were clearly visible at the edges of the landing area, spaced only 291 meters apart. The investigation established that the presence of these pylons should have allowed the pilot to deduce the existence of overhead cables and adjust the landing position accordingly. The investigation found no evidence of mechanical failure, confirming the aircraft was in an airworthy condition prior to the event.
Findings
- The primary cause of the accident was the impact between the helicopter tail and the electrical power lines.
- The main contributing factor was the pilot's failure to see the Brunico-Bolzano power lines.
- A contributing human factor was the pilot's failure to notice the highly visible pylons, which served as indicators of the overhead wires.
- The decision to perform the final approach against the sun, combined with the glare from the snowy terrain, further degraded visibility and contributed to the accident.