Accident
On July 30, 2020, about 0938 mountain daylight time, a Cessna 337F, registration N337V, was substantially damaged when it impacted remote mountainous terrain near Ennis, Montana. The aircraft was operating as a Title 14 Code of Federal Regulations (CFR) Part 91 personal cross-country flight.
Injuries
The right-front seat student pilot sustained fatal injuries. The left-front seat commercial pilot-in-command and the rear-seat passenger sustained serious injuries.
Pilot Statements
The pilot-in-command stated that the intended route was from Helena, Montana, to Jackson Hole, Wyoming. The right-seat student pilot was flying the airplane at about 3,000 ft above ground level. When the decision was made to fly over a ski resort at Big Bear, Montana, the student pilot turned the airplane southeast toward mountainous terrain. The airplane subsequently entered a boxed canyon. With a ridge in the flightpath that could not be cleared, the pilot took control and attempted an evasive maneuver. The maneuver was unsuccessful and resulted in a stall/spin, leading to impact with terrain. The pilot reported no mechanical anomalies that would have precluded normal operation and opined that the accident could have been avoided with sufficient altitude before entering mountainous terrain.
Passenger Account
The rear-seat passenger reported departure from Helena at 0845 and stated that the entire flight was flown by the front left-seat pilot. He further stated that the pilot was climbing to clear a ridge when the airplane stalled and impacted terrain in a nose-down attitude.
Toxicological Report
An autopsy on the student pilot, conducted by the Montana State Medical Examiner, noted the cause of death as multiple blunt force injuries. Toxicology testing performed by the Federal Aviation Administration Forensic Sciences Laboratory identified 11-hydroxy-delta-9-tetrahydrocannabinol (THC) in urine at 26.4 ng/mL and its metabolite, carboxy-delta-9-THC, in blood at 3.1 ng/mL and in urine at 1225 ng/mL. Delta-9-THC, the primary psychoactive component in cannabis, was not detected. The report noted that significant performance impairments are usually observed for at least 1-2 hours following cannabis use, with residual effects reported up to 24 hours, but blood level correlations to psychoactive effects remain difficult.