History of Flight
On July 19, 2015, at approximately 1915 Alaska daylight time, a Cessna U206G airplane, registration N734VB, was destroyed after impacting tree and tundra-covered terrain near Trapper Creek, Alaska. The accident occurred while the pilot was performing a series of low passes over an outdoor wedding reception. The solo commercial pilot was fatally injured. The flight was conducted under visual flight rules (VFR) as a local flight per 14 CFR Part 91, with no flight plan filed. The airplane departed a private airstrip near Curry Ridge, Alaska.
According to a witness interviewed on July 20, the airplane flew over the wedding reception at near tree-top level at an estimated speed of 100-120 knots. After two successful passes, on the third pass the airplane entered a right turn and impacted the top of a spruce tree with the main landing gear. The witness lost sight of the airplane after the treetop strike. A second witness reported that the airplane descended at near treetop level, initiated a climb before hitting a treetop, continued climbing for about 5-6 seconds, then rolled inverted and disappeared into the trees.
Pilot Information
The pilot, age 54, held a commercial pilot certificate with airplane multi-engine land, single-engine land, and instrument airplane ratings, as well as a flight engineer certificate for turbo-propeller powered airplanes. His most recent third-class medical certificate was issued on January 3, 2013, with no limitations. No personal flight records were located; FAA records indicated total aeronautical experience of about 2,100 hours, with 400 hours in the previous six months.
Aircraft Information
The airplane was a six-seat, high-wing, tricycle gear Cessna U206G, serial number U206048785, manufactured in 1979. It was powered by a Continental Motors IO-520 series engine. No airframe or engine logbooks were found; total times for engine and airframe are unknown.
Meteorological Information
At 1853, an aviation routine weather report (METAR) from Talkeetna Airport, about 6 miles east of the accident site, reported: wind 310 degrees at 3 knots, visibility 10 statute miles, clear skies, temperature 71°F, dew point 41°F, altimeter 30.13 inHg.
Wreckage and Impact
The accident site was located in densely populated birch and spruce trees at an elevation of about 436 feet mean sea level. The wreckage lay on its right side along a debris path oriented on a magnetic heading of 260 degrees, about 110 feet long. The initial impact point was marked by a broken treetop on an estimated 40-foot tall birch tree. The initial ground scar was about 65 feet from the impact point.
The cockpit area separated forward of the main landing gear box and was extensively damaged. The throttle was found in the idle position; mixture and propeller controls were full forward. The right wing separated at its forward attach point but remained attached at the rear, with a large elliptical impact area and leading edge crushing. The left wing separated into three major sections with similar impact damage. The aft fuselage and empennage exhibited accordion-style crushing. The engine separated from its mounts and came to rest inverted. The propeller and hub remained attached with all three blades exhibiting aft bending.
Control continuity: Elevator and rudder continuity were established. Aileron cables were fractured with features consistent with tension overload; no evidence of pre-impact failure. Examination of the airframe and engine revealed no mechanical malfunctions or failures that would have precluded normal operation.
Medical and Pathological Information
A postmortem examination determined the pilot's cause of death as multiple blunt force injuries. The autopsy identified severe coronary artery disease with 75-85% narrowing of the distal right coronary artery, but no gross scarring. The investigation was unable to determine if impairment from coronary artery disease contributed to the accident cause.
Toxicology testing identified diazepam (0.057 ug/ml) and nordiazepam (0.04 ug/ml) in blood, and tetrahydrocannabinol (THC) at 0.0028 ug/ml in blood. The investigation was unable to determine if the pilot was impaired by THC or the combined effects of THC and diazepam at the time of the accident.
Additional Information
The accident flight was conducted under 14 CFR Part 91. Section 91.119 prohibits operating an aircraft over an open air assembly of persons below 1,000 feet above the highest obstacle within a horizontal radius of 2,000 feet.
Tests and Research
An engine examination on July 22, 2015, found no anomalies, contamination, or evidence of malfunction. Both magnetos produced spark when rotated.