NTSB Factual Report

On July 24, 2017, about 1930 mountain daylight time, a Robinson Helicopter Company R44 II, N233JD, sustained substantial damage during a forced landing following a loss of engine power near Sutherlin Lake, Montana. The airline transport pilot and his passenger were not injured. The helicopter was registered to a private individual and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and no flight plan was filed for the cross-country flight. The flight originated from White Sulphur Springs, Montana, about 1915, with a destination of Sutherlin Lake.

The pilot reported that they were flying over the northwestern end of a lake, about 100 feet above ground level, looking for a place to land when the engine RPM and rotor RPM began to decay. The pilot stated that he decreased collective and increased throttle, however, the engine had lost power, and he initiated an autorotation into the lake. As the helicopter settled into the water, it rolled over onto its right side and became partially submerged.

Examination of the helicopter by a Federal Aviation Administration inspector revealed that the tailboom and vertical stabilizer were structurally damaged. The helicopter was recovered to a secure location for further examination.