Preliminary data based on the notification from the Norwegian authorities:
The helicopter with a pilot and three passengers from the power company performed a visual inspection of a 22 kV power line on the east side of Gullesfjorden. The inspection was flown from north to south.
At Tverrbakkhella, a closer inspection of the powerline became necessary. At this position there was a crossing 22 kV fjordspan in a northwest - southeast direction. The fjordspan crossed above the inspected power line at an angle of approx. 90 °.
The helicopter flew under the fjordspan, without detecting it. Tracks on the helicopter and electronical data indicates that the helicopter sequentially, in the right turn hooks the crossing fjordspan with the right skid in a rising motion.
The helicopter encountered a severe nose down angle after hitting the power line. The cable was cut and the helicopter regains a more horizontal flight angle and performed a successful emergency landing.