CEN18FA242

The commercial pilot, who was experienced in aerobatics, coordinated with a friend to perform a flyover of a cattle branding event. Before departing on the flight, the pilot informed his father and that he was feeling very ill and nauseated during the previous flight that day due to in-flight turbulence and informed his friend at the branding event that he may not be able to perform the flyover. The pilot subsequently flew to the cattle branding event and commenced aerobatic maneuvers, which included a loop and rolling maneuver followed by a climb in a vertical pitch attitude. The airplane subsequently rolled left and entered a left-turning spin, which continued to ground contact. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation, and autopsy and toxicology testing of the pilot identified no evidence of physiological impairment or incapacitation. Although the pilot had reported some symptoms before departing on the flight, the nature of his illness was not diagnosed, and no evidence of illness was identified on autopsy. It is possible that the pilot's undefined symptoms or illness may have contributed to the accident; however, without further evidence, it could not be determined whether or to what extent his symptoms may have affected his ability to recover from the spin maneuver.

The two-seat, high-wing, fixed-gear airplane was manufactured in 1970 and was equipped with a Lycoming O-320-A2B engine and a McCauley two-blade, all-metal, fixed pitch propeller. On October 2, 2017, the airplane underwent an annual inspection at an airframe total time of 6,507 hours and 2,194 hours since engine overhaul. The accident occurred about 26 hours after this inspection. On June 29, 2018, about 1245 mountain daylight time, a Champion 7GCAA airplane, N9026L, impacted terrain while maneuvering near Arthur, Nebraska. The commercial pilot was fatally injured, and the airplane was substantially damaged. The airplane was registered to and was being operated by Last Pass Aviation as a Title 14 Code of Federal Regulations Part 91 personal flight. Day visual meteorological conditions existed in the area of the accident, which departed without a flight plan from Thomas County Airport (TIF), Thedford, Nebraska, about 1115. The pilot was performing aerobatic maneuvers at a cattle branding event. A witness reported that, following a loop and rolling maneuver, the airplane began to climb in a vertical attitude. The airplane subsequently rolled left and made a series of left-turning spins as it descended to ground contact. The Regional West Medical Center Pathology Department, Scottsbluff, Nebraska, performed an autopsy on the pilot. The cause of death was blunt force injuries. Toxicology testing performed at the FAA Forensic Sciences Laboratory was negative for drugs and alcohol. The pilot, age 28, held a commercial pilot certificate with airplane single- and multi-engine land and instrument ratings, and a flight instructor certificate with airplane single- and multi-engine and instrument ratings. On June 26, 2018, the pilot was issued a Federal Aviation Administration (FAA) second-class medical certificate with a restriction for corrective lenses. The pilot had recently started training for agricultural application operations and had flown about 30 hours in an Air Tractor AT502 airplane. According to an insurance application from March 2018, the pilot reported that he had 1,100 hours of aerobatic flight experience in the accident airplane make and model. Most of this experience occurred while instructing spin, aerobatic, and upset recovery training at a flight school in California. The pilot's logbook was not available for review. Before departing on the accident flight, the pilot informed his father that he had been feeling very ill and nauseated during the previous flight that day due to significant in-flight turbulence. Because of this issue, the pilot informed a friend at the cattle branding event that he might not be able to perform the flyover. The airplane impacted a grassy meadow with no evidence of postimpact ground fire. Both wings were upright and exhibited significant crushing and deformation. The empennage was twisted to the left, with the outer edge of the left elevator resting near the left aileron. The engine was partially buried atan approximate 30° angle in relation to the surrounding terrain. The left gear strut was significantly deformed. The propeller remained attached to the engine. One of the propeller blades, which was buried into the ground, was nearly straight with minimal damage or polishing. The other propeller blade, which was out of the ground, was twisted aft about 180° and displayed polishing and chordwise gouges. The flight control surfaces remained attached to their respective airframe attach points and the horizontal and vertical stabilizers were not damaged. Flight control cable continuity was confirmed to all flight control surfaces with no anomalies noted. Examination of the engine revealed normal power train continuity. Thumb compression and suction were observed on all four cylinders and a borescope inspection revealed no anomalies with the pistons, cylinder barrels, cylinder heads, valves, or valve seats. The spark plugs exhibited a dark gray color and the electrodes exhibited normal wear patterns. The magnetos sparked normally at all leads during rotation. The carburetor bowl was impact damaged with no fuel present. The fuel gascolator screen, carburetor screen, and oil pickup were clear of contaminants. The engine exhaust system was impact damaged; the heat muff was intact with no cracks or exhaust erosion. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation.