HISTORY OF FLIGHT On September 23, 2011, approximately 2030 eastern daylight time, a Robinson R44 single-engine helicopter, N8324F, sustained substantial damage when it impacted trees and terrain while maneuvering near Curren, Michigan. The private pilot and passenger sustained fatal injuries. Instrument meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The flight departed the pilot's residence near Richmond, Michigan, approximately 1830, and was en route to a private hunting camp near Alpena, Michigan. According to local authorities, the pilot and passenger were en route to a hunting camp near Alpena, Michigan. A witness, located approximately 40 acres south of the accident site, observed the helicopter flying overhead at 300 feet above ground level. The helicopter was in cruise flight with all of its light illuminated. The witness did not hear any abnormal engine sounds or mechanical issues. The witness added the helicopter appeared to be traveling about 90 miles per hour and it was raining heavily. The witness did not hear any abnormal engine sounds or mechanical issues. About 20 seconds after the helicopter disappeared from sight, the witness heard a series of sounds like gun shots and did not think anything of the sounds until he heard about the accident a day or so later. The witness stated he thinks the gun shot sounds were the helicopter impacting the trees. The helicopter was reported by family as overdue on September 25th at 1000 and was located at 1100 by land owners. PERSONNEL INFORMATION The pilot held a private pilot certificate with a rotorcraft rating and did not possess an instrument rating. The pilot's most recent third class medical certificate was dated May 8, 1998. The pilot's family indicated the pilot did not log flight time hours after he obtained his private pilot certificate. The pilot's log book was not located during the investigation. A Robinson helicopter instructor/pilot evaluation, dated March 15, 1999, indicated the pilot had 335 helicopter flight hours, and 196 hours in the Robinson R44. The instructor's general comments stated, "flew [SIC] R44 very well." AIRCRAFT INFORMATION The four-seat, single main rotor, single-engine helicopter, serial number 202, was constructed primarily of metal, and manufactured in 1995. The primary structure of the fuselage was welded steel tubing and riveted aluminum sheet. The tailcone was a monocoque structure in which aluminum skins carried most of the primary loads. Fiberglass and thermoplastics were used in the secondary structure of the cabin, engine cooling system, and in various other ducts and fairings. The helicopter was powered by a 260-horsepower Lycoming O-540-F1B5 series engine (serial number L-24882-40A), with a maximum continuous rating of 205-horsepower at 2,718 rpm. Review of the maintenance records revealed the most recent annual inspection was completed on August 26, 2010, at a time in service of 549.3 hours. The total airframe and engine hours at the time of the accident could not be determined. According to the Pilot's Operating Handbook, the helicopter was certified to be operated under visual flight rules flight only. METEOROLOGICAL INFORMATION At 2054, the Alpena Municipal Airport automated surface observing system (ASOS), located approximately 20 miles north of the accident site, reported the wind from 330 degrees at 7 knots, visibility 6 miles, light rain, mist, sky broken at 800 and 1,600 feet above ground level (agl), overcast ceiling at 2,200 feet agl, temperature and dew point 11 degrees Celsius, and an altimeter setting of 30.00 inches of Mercury. On the day of the accident, the sun set at 1930, and the end of civil twilight was 1959. The moon rose at 0237 and set at 1709. According to a Safety Board senior meteorologist, satellite observation indicated solid cloudy conditions in the accident site area near the accident time, with cloud tops varying. An AIRMET (Airmen's Meteorological Information) for instrument flight rules conditions was near to the accident location. The Area Forecast included marginal visual flight rules conditions with isolated light rain showers. According to the Lockheed Martin Office of Quality Assurance, the pilot did not request a weather briefing nor file a flight plan prior to the accident flight. Investigators were unable to determine if the pilot received a weather briefing from approved weather sources prior to the accident. WRECKAGE AND IMPACT INFORMATION The accident site was located in a wooded area approximately 20 miles south of the destination hunting camp. Examination of the wooded area revealed the helicopter impacted several trees prior to coming to rest inverted. A postimpact fire ensued and partially consumed the main wreckage. The main wreckage consisted of the engine, transmission, main rotor mast and hub, and tail boom. The wreckage debris field, orientated on a 010 magnetic degree heading, was approximately 500 feet in length. The wreckage debris field contained fragmented sections of the fuselage, main rotor blades, landing gear skid tubes, tail rotor gearbox, tail rotor blades, and Plexiglas. Examination of the airframe and flight control system components revealed no evidence of a preimpact mechanical malfunction. Flight control continuity could not be established due to impact, fire, and missing components, but control fractures located were consistent with overload or fire damage. Flight instruments located were either destroyed, or provided no useful information. Examination of the main gearbox, forward flex coupler, overrunning clutch, intermediate flex coupler, tail rotor drive shaft, aft flex coupler, main gearbox and tail rotor gear box chip detectors revealed no evidence of a preimpact mechanical failure or malfunction. Drive continuity was established from the main rotor hub to the belt pulley. Investigators from the National Transportation Safety Board (NTSB) and Lycoming engines examined the engine. Examination of the recovered engine assembly and accessories revealed no anomalies. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot on September 27, 2011, by the Saginaw County Medical Examiner's Office. The autopsy reported the cause of death as multiple blunt force trauma. Forensic toxicology testing was performed on specimens from the pilot at the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The tests were negative for carbon monoxide, cyanide, and ethanol. The following drugs were detected: 116.9 (ug/ml, ug/g) Acetaminophen detected in Blood 0.036 (ug/mL, ug/g) Alpha-hydroxyalprazolam detected in Blood 1.09 (ug/ml, ug/g) Benzoylecgonine detected in Blood 2.302 (ug/ml, ug/g) Benzoylecgonine detected in Liver 0.04 (ug/ml, ug/g) Cocaine detected in Blood 0.082 (ug/ml, ug/g) Cocaine detected in Liver Desmethylsildenafil detected in Liver Desmethylsildenafil detected in Blood 0.054 (ug/mL, ug/g) Dihydrocodeine detected in Blood 0.051 (ug/mL, ug/g) Dihydrocodeine detected in Liver 0.039 (ug/ml, ug/g) Diphenhydramine detected in Blood Diphenhydramine detected in Liver Ecgonine Methyl Ester detected in Blood Ecgonine Methyl Ester detected in Liver 0.179 (ug/ml, ug/g) Hydrocodone detected in Liver 0.506 (ug/ml, ug/g) Hydrocodone detected in Blood Ibuprofen detected in Blood Pseudoephedrine detected in Blood TEST AND RESEARCH A Garmin Global Positioning System III+ was recovered from the accident site and sent to the NTSB's Vehicle Recorder Laboratory for data recovery. Examination of the data showed 5 user defined waypoints, 0 user defined routes, and 13 track logs dated from October 12, 2008, to May 1, 2011. No track log or accident data was recorded on the accident date; however, the data showed a similar route of flight on multiple previous occasions. Review of the Robinson R44 Pilot's Operating Handbook, Safety Notice SN-26, Night Flight Plus Bad Weather Can Be Deadly states, "Many fatal accidents have occurred at night when the pilot attempted to fly in marginal weather after dark. The fatal accident rate during night flight is many times higher than during daylight hours. When it is dark, the pilot cannot see wires or the bottom of clouds, nor low hanging scud or fog. Even when he does see it, he is unable to judge its altitude because there is no horizon for reference. He doesn't realize it is there until he has actually flown into it and suddenly loses his outside visual references and his ability to control the attitude of the helicopter. As helicopters are not inherently stable and have very high roll rates, the aircraft will quickly go out of control, resulting in a high velocity crash which is usually fatal. Be sure you NEVER fly at night unless you have clear weather with unlimited or very high ceilings and plenty of celestial or ground lights for reference."