On March 7, 2018, about 1400 central standard time, a Hughes 369D helicopter, transporting a powerline worker via a long line, was involved in an accident near Blair, Wisconsin, when the worker contacted the powerlines and received serious injuries. The helicopter was not damaged and the pilot received no injuries. The helicopter was registered to HLH Holdings, LLC, and was operated by High Line Helicopters, LLC, under the provisions of 14 Code of Federal Regulations Part 133 as a Rotorcraft External-Load Operation. Visual meteorological conditions prevailed for the flight, which was not on a flight plan. The local flight had just originated when the accident occurred. The pilot reported that the purpose of the flight was to lift a utility lineman using the helicopter so that the lineman could install components in conjunction with a new powerline project. He stated that once the lineman hooked up to the long line he proceeded to lift the lineman up to a nearby structure but the lineman contacted an existing powerline. The lineman was subsequently set back on the ground to await emergency services. The lineman suffered severe injuries as a result of the accident.. The pilot reported that the powerline that the lineman struck was not visible from the pilot's perspective until it was too late to correct course. He also reported as a recommendation: "Better recognition of hazards and obstructions while performing external load operations." The weather conditions reported at a nearby airport included a broken ceiling at 3,700 ft above the ground, 10 miles visibility and no precipitation.