Flight History
On 6 April 2020, the commander of Airbus Helicopters AS350 B3, registration LN-OFQ, was tasked with moving a container weighing just under 1,100 kg as part of a power transmission line construction project. The helicopter was equipped with a 15-metre longline and a 6-metre extension, attached to a lifting yoke for the 2-metre-high container, requiring an altitude of approximately 24 metres above ground to lift the load.
The commander departed rig area C42 at 0839 hours local time with 35% fuel (approx. 190 litres) and approximately 20 kg of equipment. En route, he noted strong southeasterly winds with gusts. He initially landed near pylon 151 but realized it was the wrong location; the correct pylon was approximately 10 NM further northeast on the eastern side of the Høgsfjord. After consulting with the client and a colleague, he decided to fly to rig area C32 to reassess conditions.
Accident Sequence
The helicopter remained on the ground with the engine running for nearly seven minutes. When the commander lifted off, the container was positioned in front and to the right. He turned left to a heading of about 140 degrees, keeping the line taut in his right-side view. As the longline became taut, a wind gust occurred, causing the helicopter to roll left and pitch up. The commander applied forward and right cyclic, but the helicopter continued rolling. At 11.6 degrees of roll, the situation progressed into a dynamic rollover, and the helicopter crashed.
Aircraft and Personnel Information
The helicopter, an Airbus Helicopters AS350 B3, was Norwegian-registered (LN-OFQ), owned by Skjolden Invest AS, and operated by Helitrans AS. The sole occupant, the commander, sustained minor injuries; the NSIA noted his helmet use prevented further injury. The helicopter was destroyed. No passengers were on board.
Weather Conditions
Windy conditions with strong gusts were reported. The forecast wind for the area was above the operator's 30-knot limit for sling load operations. Local wind variations were common; exact wind conditions at the accident site were unknown.
Survival Aspects
The commander was alone and only lightly injured. The NSIA attributed the absence of more serious injury to his use of a helmet.