On March 25, 2016, about 1730 central daylight time, a Brantly B-2B helicopter, N2266U, collided with trees and terrain following a loss of control in Galena, Missouri. The pilot received serious injuries. The helicopter was substantially damaged. The helicopter was owned and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight originated from private property in Cape Fair, Missouri about 1715.The pilot flew the helicopter to a restaurant located about 4 miles from the accident site, where he ate. A witness reported the pilot then started the helicopter and as it was warming up, the engine backfired. The witness reported the engine did not sound "right" to him as the helicopter took off and he thought it was going to contact the trees prior to it gaining sufficient altitude. The pilot flew about 4 miles southeast where another witness, located across the street from the accident site, saw the helicopter. This witness stated the helicopter circled his property three times, in a clockwise direction. The second pass was about 40 to 60 ft above the trees, during which, he waved to the pilot and the pilot waved back. The helicopter looked as if it was going to land on the third pass as it was about 20 ft above the ground before it climbed out. As the helicopter climbed, the engine power sounded like it was fluctuating. He then saw the tail "dip" and the helicopter began to spin. He lost sight of the helicopter behind the trees, then heard the impact. He stated the engine of the helicopter continued to run for several minutes after the impact. This witness took several photographs of the helicopter as it circled his residence. Another witness heard the helicopter from inside her house. She stated she went outside and saw the helicopter circle the area three times at an "unusually" low altitude. She stated the helicopter was about 20 ft above the trees in a level attitude when it started spinning to the left and descending. She also stated the engine continued to run after the impact. The helicopter came to rest in a heavily wooded area. First responders reported the helicopter was leaking fuel when they arrived. A postaccident examination of the wreckage was conducted by a Federal Aviation Administration Inspector. The tailboom was separated from the fuselage which came to rest in a nose down attitude. The red blade was separated from the mast, and the outboard sections of all three main rotor blades were fractured and separated from the inboard sections. The main rotor shaft and planet gear assembly sustained impact damage. Continuity of the rudder control system was established and all separations appeared to be overload. No anomalies were noted that would have resulted in a loss of control or loss of engine power. The pilot held a private pilot certificate with an airplane single-engine land rating. He did not hold a helicopter rating. A review of the pilot's logbook indicated he had 191.8 hours of helicopter flight time, 119.6 hours of which were logged as pilot-in-command. The pilot logged 122.6 hours in the accident make and model helicopter. At 1850, the reported wind conditions at the Branson Airport, located 18 miles southeast of the accident site, were 110 degrees at 12 knots. The National Transportation Safety Board was subsequently notified that the pilot passed away on June 9, 2016.