WPR17FA035

The commercial pilot was departing on a routine positioning flight in dark night visual meteorological conditions. Footage from a security camera at the airport showed the airplane take off normally and initiate a right turn, which was the established direction of traffic for the takeoff runway. The airplane continued the right turn, then entered an increasingly rapid descent and subsequently impacted terrain about 1 mile southwest from the airport. The wreckage distribution was consistent with a high-energy impact. Examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or anomalies that would have precluded normal operation. Autopsy and toxicology testing of the pilot did not reveal any evidence of impairment or incapacitation. Visual conditions prevailed in the area at the time of the accident; however, the setting Moon was obscured by cloud cover, and the airport was located in an area of remote, sparsely-populated high desert terrain. This would have resulted in few visual references to which the pilot could have oriented the airplane. Although the pilot had experience operating in this environment in night conditions and held an instrument rating, the circumstances of the accident are consistent with the known effects of spatial disorientation. The investigation could not determine the initiating event which led to the pilot's mismatch between the airplane's perceived and actual attitude; however, he likely experienced a sensory illusion as a result of spatial disorientation, which led to a loss of control.

According to an FAA Safety Team pamphlet, "Spatial Disorientation:" Sight, supported by other senses, allows a pilot to maintain orientation while flying. However, when visibility is restricted (i.e., no visual reference to the horizon or surface detected) the body's supporting senses can conflict with what is seen. When this spatial disorientation occurs, sensory conflicts and optical illusions often make it difficult for a pilot to tell which way is up. Contributing to these phenomena are the various types of sensory stimuli: visual, vestibular (organs of equilibrium located in the inner ear), and proprioceptive (receptors located in the skin, muscles, tendons, and joints). Changes in linear acceleration, angular acceleration, and gravity are detected by the vestibular system and the proprioceptive receptors, and then compared in the brain with visual information. In the flight environment, these stimuli can vary in magnitude, direction, and frequency, resulting in a "sensory mismatch" that can produce illusions and lead to spatial disorientation. The two-seat, high wing, fixed-gear airplane, serial number 100-0140, was manufactured in 2015 and was configured to carry cargo. It was powered by a Pratt and Whitney PT6A-34, 750-horsepower turbine engine equipped with a Hartzell HC-E4N-3P, four-blade, controllable-pitch propeller. The airplane's most recent 200-hour inspection was conducted on November 10, 2016, at an airframe total time of 473.5 hours. At the time of the accident, the airplane had 504.2 total airframe hours. CNY is a non-towered/uncontrolled facility at a field elevation of 4,557 ft mean sea level; the airport was located in an area of remote, sparsely-populated high desert terrain. The airport has one runway, runway 3/21, which is 7,100 ft long and 75 ft wide. The published traffic pattern for runway 21 includes right turns. On December 12, 2016, about 0537 mountain standard time, a Quest Kodiak, N772RT, was destroyed when it impacted terrain shortly after takeoff from Canyonlands Field Airport (CNY), Moab, Utah. The pilot was fatally injured. The airplane was registered to Lease Air LLC, and operated by Aerowest Aviation, dba Redtail Air, under the provisions of 14 Code of Federal Regulations Part 135. Visual meteorological conditions prevailed, and a visual flight rules company flight plan was filed for the positioning flight, which was originating at the time of the accident. The flight's intended destination was Salt Lake City International Airport (SLC), Salt Lake City, Utah. Review of security camera footage showed that the pilot boarded the airplane about 0526, started the engine about 0529, and subsequently taxied to runway 21 for takeoff. The pilot activated the runway lights about 0534, and the airplane took off about 0536. The takeoff appeared normal and the airplane initiated a right turn after becoming airborne. Shortly thereafter, the airplane entered an increasingly rapid descent that continued to ground contact.The Utah Office of the Medical Examiner, Salt Lake City, Utah, performed an autopsy of the pilot. The cause of death was listed as total body blunt force injuries. The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed forensic toxicology on specimens from the pilot, with no ethanol or tested-for drugs detected in urine. The 0553 weather observation at CNY included wind from 330° at 4 knots, visibility 10 statute miles, clear skies below 12,000 ft, temperature 1°C, dewpoint -2°C, and an altimeter setting of 29.94 inches of mercury. Satellite imagery indicated a broken layer of high cirriform clouds with tops near 21,000 ft. According to the United States Naval Observatory, the Moon phase for the morning of the accident was a waxing gibbous, with about 97% of the Moon's visible disk illuminated. Moonset occurred at 0536; at 0540, the Moon was -1.5 degrees below the horizon at an azimuth of 290°. The pilot held a commercial pilot certificate with ratings for airplane single engine land and instrument airplane; in addition, a flight instructor certificate with ratings for airplane single engine and instrument airplane. He held a Federal Aviation Administration (FAA) second-class medical certificate issued February 1, 2016, with the limitation that he must wear corrective lenses for near and distant vision. The operator reported that the pilot had 4,635 total hours of flight experience, of which 243 hours were in the accident airplane make and model. The pilot had 170 total hours of night experience, and 291 hours in actual instrument conditions. The airplane descended through two 30-40 ft-tall powerlines about 1 mile southwest of the airport before impacting terrain below. The debris field was about 323 ft long and extended beneath the powerlines on a magnetic heading of 359°. The first piece of debris was the flange from the right wheel, followed by outboard right wing components. A large impact crater contained two propeller blades, some instruments, and right wing aileron and flap components. Various pieces of debris from the right wing, instrument panel, and cabin area extended from the impact crater about 134 ft to the main wreckage. The main wreckage included the engine, cabin, fuselage, and empennage, and was consumed by postimpact fire. Beyond the main wreckage were components from the left wing and inboard right wing. The final piece of debris was the right tire. Two of the four propeller blades exhibited striations and damage consistent with impact with powerlines. These blades were fracture-separated from the hub and located in the impact crater. The cabin area was heavily damaged and burned; the flight instruments were heavily fragmented. Continuity of all primary flight controls was established from the cabin area to the respective flight control surfaces. Examination of the engine revealed that both the front and aft sections were bent toward the right side, giving the engine a half-circle appearance.The casing from the power section of the engine was heavily twisted and sustained heavy inward crush damage at the C-flange. Dirt, airframe fragments, stator vanes, and fragmented pieces of the power turbine were removed from this area, revealing the power turbine and a few compressor blades. The visible power turbine blades were fractured about midspan and the outer fragments were found within the exposed area. The fracture surfaces were rough. In addition, scoring was noted along the inside edge of the casing. A few compressor blades could be seen through the stator and the leading edges displayed a "chewed" appearance. An internal examination with a borescope revealed no evidence of heat distress, and several blade fragments were observed forward of the power turbine. Examination of the airframe and engine revealed no evidence of any preimpact mechanical malfunctions or anomalies that would have precluded normal operation.