HISTORY OF FLIGHT On August 20, 1995, about 0840 mountain daylight time, N1930Q, a Cessna 177RG, operated by the owner/pilot, impacted mountainous terrain during descent and was destroyed near Thompson, Utah. The private pilot was fatally injured, and his passenger received minor injuries. Marginal visual meteorological conditions prevailed and no flight plan had been filed. The personal flight departed from Provo, Utah, and was destined for Grand Junction, Colorado. The flight was conducted under 14 CFR 91. According to the surviving passenger: ... the pilot...decided to divert to Rangely, CO to avoid bad weather encountered in the Grand Jct. area. [The pilot] turned the plane towards Rangely which was visible northeast of our present location. We suddenly encountered severe clear air turbulence and rapidly lost altitude. Our altitude at the time of the turn was 10,500 feet [msl]. The loss of altitude was so sudden and severe that my body was straining against my seat belt. I could see vapor condense in the vortices on the nose and canopy. The noise was similar to a jet engine at full throttle. The pilot and I had no time to communicate before we dropped into a cloud bank and impacted with the ground. The passenger stated that he did not perceive any mechanical deficiencies with the airplane. According to five ground witnesses, who were at a hunting camp near the accident site, the airplane was flying between 300 feet and 500 feet above the ground just prior to the accident. One of the witnesses, located about 300 yards from the accident site, stated that he observed the airplane fly over his head at a "low" altitude heading southwest. He lost sight of the airplane in the overcast, and then heard the impact of the airplane with trees. Another witness stated that he did not see the airplane, but heard the engine at impact. The accident occurred during the hours of daylight and was located at 39 degrees, 25.33 minutes North; 109 degrees, 20.90 minutes West. PERSONNEL INFORMATION The pilot, age 50, was a certificated private pilot with a rating for single-engine land airplanes. The pilot was not instrument-rated. According to FAA records, the pilot was issued an FAA Third Class Medical Certificate on September 4, 1985. The certificate was not valid at the time of the accident flight. The pilot's logbook was not recovered. METEOROLOGICAL INFORMATION According to one of the ground witnesses, the cloud ceiling near the accident site at the time of the accident was about 400 to 500 feet above the ground. This witness also observed fog and "poor" visibility. Other witnesses stated that the ground visibility was less than 200 feet in fog when they reached the accident site immediately following the accident. Another witness stated that a wind from the southeast was blowing about 20 miles per hour. This witness stated that the wind was blowing fog up to where he was camping, located about 100 yards south of the accident side. Initial tree strikes were located at the top of a ridge on the leeward side of the witness' location. The closest weather observation station to the accident site is Grand Junction, located about 30 nautical miles southeast of the accident site. About 10 minutes after the accident, Grand Junction reported the following: Scattered clouds at 6,000 feet above the ground (10,858 feet msl); broken cloud ceiling of 9,500 feet above the ground (14,358 feet msl); winds at 120 degrees at 9 knots. WRECKAGE AND IMPACT INFORMATION The airplane wreckage was examined at the accident site one day after the accident, August 21, 1995, by an FAA aviation safety inspector from Salt Lake City, Utah. According to the inspector, the length of the wreckage path was about 1,000 feet and was oriented along a magnetic bearing of 088 degrees. The wreckage was found on a plateau along the leeward side of a mountain ridge at an elevation of 8,100 feet msl. An examination of the airframe and engine did not reveal evidence of preimpact mechanical malfunction. No evidence of fire or explosion was found. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot by Dr. Maureen Frikke, M.D., of the State of Utah Office of the Medical Examiner, Salt Lake City, Utah, on August 21, 1995. A toxicological analysis (attached) was performed on specimens taken from the pilot by the FAA Civil Aeromedical Institute, Oklahoma City, Oklahoma.