History of Flight
On July 1, 2017, about 0730 Pacific daylight time, a North Wing Scout XC light sport weight-shift-control (WSC) aircraft, registration N492XB, was destroyed when it impacted mountainous terrain while maneuvering near Chelan, Washington. The flight instructor and student pilot sustained fatal injuries. The aircraft was owned by the flight instructor, who was operating it under Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which originated from Lake Chelan Airport (S10), Chelan, Washington, about 0630.
Video from an onboard camera revealed that earlier that morning, the student pilot completed a checkride to obtain a sport pilot certificate. The instructor informed the student pilot of successful completion. They subsequently departed again and continued flying locally. The video showed the pilots stayed in the traffic pattern before departing east. As the aircraft climbed away from the airport, the pilots discussed finding an area with less turbulence. About 19 minutes after takeoff for the accident flight, the instructor took over the flight controls and began demonstrating a spiral dive. As he entered the maneuver, the aircraft's bank angle increased, and the aircraft rotated nearly 360° with its nose pointing straight down. The video stopped recording upon impact.
Personnel Information
The instructor, age 70, held a private pilot certificate with single-engine land rating and a flight instructor certificate for light sport aircraft. He was issued a third-class FAA medical certificate on April 19, 2016, with a limitation requiring glasses for near vision. On the medical application, he reported 6,000 total flight hours, with 100 hours in the previous six months. His logbook showed 3,012.9 hours in the WSC trike category.
The student, age 48, held a student pilot certificate and was not required to have an FAA medical certificate. His logbooks were not available, and his flight experience could not be determined.
Aircraft Information
The aircraft was a 2014 North Wing Scout XC, purchased by the instructor in May 2017. Maintenance records were not located, and maintenance history could not be determined. It was equipped with a Rotax 912 series, 80-horsepower reciprocating engine in a pusher arrangement behind the rear seat, electronically controlled, driving a 3-blade composite propeller. The primary pilot station was the front seat; the rear seat had no instrument access. Both occupants had access to the control bar. Evidence suggested the pilot occupied the rear seat and the student the front seat.
Meteorological Information
At 0655, an automated observation at Pangborn Memorial Airport (EAT), Wenatchee, Washington, about 35 miles southwest of the accident site, reported wind from 310° at 11 knots, visibility 10 miles, temperature 24°C, dew point 9°C, and altimeter 29.91 inches of mercury.
Wreckage and Impact Information
The aircraft impacted terrain near the top of a hill in mountainous, rocky terrain and was destroyed by impact forces. The debris path was oriented on a heading of about 130° magnetic. The first identified point of contact (FIPC) was a rock about 25 feet below the hill summit, with disturbed dirt and debris including the front steering fork and brake reservoir. A canopy portion was left of the FIPC. The main wreckage, including most of the airframe, engine, wing, main landing gear, and propeller, was about 50 feet from the FIPC on a heading of 320°, indicating it rolled downhill after impact. One propeller blade was fractured and located about 30 feet north of the main wreckage. The rear seat was in the main wreckage; the front seat was along the debris path. Multiple separations in the flight control system were observed, with fracture surfaces consistent with overload.
Engine examination showed cylinders, crankcase, and overhead components intact with no catastrophic failure. Disassembly revealed no abnormal wear or internal component failure. Impact damage was negligible to crankcase, reduction gear case, cylinders, and accessory section. Rocker arm, valve train, and accessory gear continuity were established by rotating the crankshaft by hand. All four cylinders developed compression. Internal borescope examination of pistons and cylinders showed no anomalies. Spark plugs had normal wear. Impact damage was noted to both carburetors and ignition system. No pre-impact mechanical malfunction or failure was evident.
Medical and Pathological Information
The King County Medical Examiner conducted autopsies on the instructor and student pilot. The cause of death for both was multiple blunt force injuries. The FAA Bioaeronautical Sciences Research Laboratory performed toxicology. For the instructor, ethanol was detected in muscle and brain, propanol in muscle, and atorvastatin in liver. Ethanol can be produced postmortem; atorvastatin is not impairing. Tests for cyanide and carbon monoxide were not performed. For the student, ethanol was detected in muscle but not liver; no drugs were detected. Tests for cyanide and carbon monoxide were not performed.