On July 14, 2005, at 1945 mountain daylight time, a Cessna TU206F, N1059V, was substantially damaged when it impacted terrain and nosed over during takeoff from a dirt airstrip, approximately 54 miles south of Vernal, Utah, in the Uintah and Ouray Indian Reservation. Visual Meteorological conditions prevailed at the time of the accident. The contracted passenger-carrying flight was being conducted under the provisions of Title 14, Code of Federal Regulations, Part 135, without a flight plan. The commercial pilot and four passengers on board sustained minor injuries. The cross-country flight from the airstrip to Vernal was originating at the time of the accident. The airplane's owner said they were taking off to the south from the Flat Rock Airstrip. The owner said that the airplane got off the ground and encountered windshear. The wind blew him sideways. He went off the side of the runway. His wheels got caught in the sagebrush which flipped him over. The pilot said he landed at the dirt strip to the north. He checked the temperature and winds then took off to the south. At approximately 3 to 4 feet off the ground, the pilot said the airplane encountered a windshear. He said it occurred just after rotation. The pilot said he lost control of the airplane, dropped to the ground to the right of the runway, hit the sagebrush, and nosed over. The passengers stated that the wind conditions were "calm" and they "felt no turbulence or shear during this departure." One passenger said that the airplane accelerated in a "zig zag" manner and then lifted off, and that it was smooth once airborne. The passenger said they climbed "20 to 40 feet high, then the airplane abruptly pitched nose down sinking until catching the sage brush ..." Another passenger said the airplane started on the left side of the runway in soft dirt and accelerated along the left side. He said the airplane "lifted off at a slow speed, climbed 30 to 40 feet high, then sunk back to the surface ..." At 1953, the Routine Airport Weather Observation (METAR) at Vernal, Utah, 351 degrees at 54 miles from the accident site was clear skies, visibility 10 statute miles, winds 270 degrees at 4 knots temperature 70 degrees Fahrenheit (F), dew point 48 degrees F, and altimeter 30.15 inches. At 1953, Moab, Utah, METAR, 170 degrees at 49 miles from the accident site reported clear skies, 10 statute miles visibility, winds 140 degrees at 3 knots, temperature 81 degrees F, dew point 35 degrees F, and altimeter 30.07 inches. At 1953, Price, Utah, METAR, 250 degrees at 50 miles from the accident site reported clear skies, 10 statute miles visibility, winds calm, temperature 72 degrees F, dew point 41 degrees F, and altimeter 30.19 inches. At 1953, Grand Junction, Colorado METAR,085 degrees at 57 miles from the accident site reported clear skies, 10 statute miles visibility, winds 110 degrees at 11 knots, temperature 77 degrees F, dew point, 39 degrees F, and altimeter 30.13 inches. The estimated density altitude for the area was 9,856 feet. The airplane was examined at the scene. The airplane rested inverted approximately 25 feet west of the airstrip. The right wing tip was crushed aft. The left outboard wing was bent downward approximately 85 degrees at mid-span. The aft fuselage was bent and buckled downward approximately 30 inches forward of the empennage. The vertical stabilizer leading edge was crushed aft starting at mid-span and moving upward toward the top. The nose gear was broken aft. The propeller blades showed torsional bending and chordwise scratches. Flight control continuity was confirmed. An examination of the airplane's engine, engine controls and other airplane systems revealed no anomalies. According to the FAA, the passengers were employees for a drilling company. The company does hard rock drilling in the area around the airstrip. They had been in and out of that airstrip 30 to 40 times. The FAA reported that the company uses other airstrips in the area too. The FAA reported that the airstrip had been recently graded. The center of the runway was hard. The sides were soft. According to the drilling company, the company had chartered the airplane to take the drilling crew from Vernal to the Flat Rock Airstrip and back. FAA reported the pilot was not certified to fly under Title 14 CFR Part 135, on-demand air taxi. The pilot had completed a flight review on September 13, 2003. The pilot had not completed a Part 135 checkride prior to conducting the flight.