Loss of Control in Flight · NTSB WPR20LA245
Cessna 337 — Ennis, MT
| Date | July 30, 2020 |
| Location | Ennis, MT |
| Aircraft | Cessna 337 |
| Purpose of flight | Personal |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Uncontrolled descent Collision with terr/obj (non-CFIT) |
| Pilot age | 27 |
| Pilot total time | 671 hrs · Building experience |
| Time in type | 37 hrs |
| Fatalities | 1, 2 serious |
Probable cause
NTSB findings
- Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Airspeed-Not attained/maintained
- Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Angle of attack-Capability exceeded
- Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot
- Personnel issues-Psychological-Attention/monitoring-Monitoring environment-Pilot
- Environmental issues-Physical environment-Terrain-Mountainous/hilly terrain-Effect on operation
What happened
The left seat pilot-in-command (PIC) reported that, he passed the controls to the right seat student pilot once they were en route on the accident flight. The rear seat passenger’s postaccident statement indicated that the left seat pilot was at the controls for the duration of the flight; however, he may not have seen the exchange of the flight controls as he was seated behind both pilots at the time. As they were flying southbound on the cross-country flight over a valley about 3,000 ft above ground level, they agreed that they wanted to view a resort in the area. The student pilot then turned the airplane to the southeast towards higher mountainous terrain. After the airplane had entered a boxed canyon, and with a ridge in the airplane’s flightpath that it could not clear, the PIC took control of the airplane and attempted an evasive maneuver to reverse course to exit the canyon. However, during the maneuver, the PIC likely did not maintain sufficient airspeed, which resulted in an aerodynamic stall/spin and subsequent impact with remote mountainous terrain. The PIC reported no mechanical anomalies with the airplane that would have precluded normal operation.
Toxicology results indicated that the student pilot had used cannabis, but likely had metabolized it such that no detectable psychoactive chemicals remained in his blood. The toxicology results and the student pilot’s limited role in the accident flight suggest that the effects of cannabis use were unlikely to have contributed to the accident.