On December 21, 2015, about 2130 central standard time, a Schweizer 269C helicopter, N292B, registered to the pilot, was destroyed after it impacted terrain after encountering fog while maneuvering near Warrenton, Missouri. The private pilot, who was the sole occupant, sustained minor injuries. The flight was being conducted under the provisions of Federal Aviation Regulations Part 91. Dark night instrument meteorological conditions (IMC) prevailed in the accident and a flight plan was not filed. The flight originated from Moscow Mills, Missouri, about 2100 and was enroute to the pilot's private home helipad in Waynesville, Missouri. The pilot reported that he checked the weather before he departed Moscow Mills and said that the weather was good (6 miles visibility and clear skies). He said that there was a slight haze upon departure, about 100 feet AGL, and climbed to his planned enroute altitude of 2,000 AGL. The first 15 minutes of the flight were uneventful until he approached the Missouri River area. He stated that he started to lose visual reference to the ground, but thought it was just a small area of fog and that he would fly out of it soon. He tried to descend but did not see the ground through the fog/low clouds and initiated a climb. He stated that his altitude ranged from about 1,200 to 2,000 feet AGL. He then decided that he should turn around and exit the way he came in. He started a slow right turn and after established in the turn, the helicopter struck a tree. The pilot tried to initiate a climb and the helicopter struck another tree. The pilot lowered the collective and the helicopter descended through the trees to the ground. Figure 1. Overhead View of Accident Area and Location of Weather Reporting Facility The automated weather facility at Washington Municipal Airport (FYG) was located about 11 miles southwest of the accident site, at an elevation about 200-250 feet lower than the accident site. The FYG METAR observation at 2135 showed reduced visibility (5 statute miles with mist), a 1-degree dew point depression, and a cloud ceiling of 1,000 feet AGL (which would reference about 750 feet above the accident site elevation). The pilot reported in a statement that he received an adequate weather briefing prior to departure. It is unknown where the pilot obtained his weather briefing and the helicopter did not have on-board weather monitoring equipment installed. With the weather information that the pilot reported, and the automated weather reported from the FYG reporting station, VMC conditions prevailed at the departure location when the pilot initiated the flight, however, IMC conditions were encountered near the accident area.