Accident Overview
On 14 December 2017 at approximately 1120 local time, an Airbus Helicopters AS350 B3, registration LN-OPA, was conducting a commercial cargo flight at Brettesnes in Lofoten, Norway. The helicopter had arrived about 30 minutes earlier and landed on a pier. The pilot and a load master unloaded a concrete stub packed in a large bag (bigbag) and placed it about 3 m from the helicopter. Inside the bigbag they placed an empty 60-liter barrel, a shackle bag weighing about 20 kg, a 15 m longline, and four folded empty bags. The filled bigbag was positioned about 5 m from the helicopter. Other equipment was placed about 3 m away on top of several new folded bags.
Sequence of Events
The pilot attached a longline and instructed the load master to hold the filled bag on the ground while the helicopter took off for the first lift. The helicopter faced west with a southern wind of 15–20 kt. No movement of the bag was observed during takeoff. After the first lift, the pilot returned and retrieved the concrete stub, flying it to a concrete truck about 20 m north on the pier. During the following half-hour, the wind decreased to 10–15 kt. Upon returning to the landing area, the load master guided the helicopter down while pulling the longline toward himself.
About 1 m before touchdown, the pilot saw an orange bag fly up, drawn into the rotor downwash, and enter the main rotor. The helicopter vibrated violently for approximately 2 seconds before landing. Even on the ground with the engine at idle, vibrations continued but less intensely. The emergency locator transmitter activated automatically but was turned off by the pilot. The load master took cover behind sand piles. After about 10 seconds, the pilot unfastened his seatbelt, disconnected his helmet lead, set the start selector to OFF, applied the rotor brake, and exited the helicopter, running clear.
The bag that struck the rotor landed about 25 m from the helicopter. All contents that had been inside the bag remained at the original location. None of the equipment from the other pile (on top of new flattened bags) was lifted.
Damage and Injuries
No persons were injured. The helicopter sustained major damage to the main rotor and multiple structural fuselage damages due to vibrations after the bag struck the rotor.
Operator's Procedures and Subsequent Actions
The operator, Helitrans AS, had previously introduced the use of highly visible orange bags (instead of white, less-visible ones) based on suggestions from a safety forum. Following this accident, Helitrans implemented an immediate prohibition on having bigbags outside the helicopter, requiring them to be placed at a safe distance beyond the downwash area. The prohibition was extended to all light objects that could become airborne. The company also addressed the topic of loose objects on landing sites in operational meetings and at the Helicopter Safety Forum in January 2018.
Investigation Findings
The accident occurred because the landing site was not adequately secured. The downwash from the landing helicopter caught the filled bag; the weight of its contents was insufficient to prevent it from being lifted and emptied. The southern wind likely intensified the airflow toward the helicopter, further lifting the bag into the main rotor. This caused an imbalance and ground resonance, resulting in additional damage. Bags closer to the helicopter, weighted down with heavy items and being new and tightly folded, were not lifted. The investigation noted that securing landing sites remains a recurring issue.