Loss of Control in Flight · NTSB CEN21FA007
BEECH S35 — Telluride, CO
| Date | October 5, 2020 |
| Location | Telluride, CO |
| Aircraft | BEECH S35 |
| Purpose of flight | Personal |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Enroute-climb to cruise Loss of control in flight |
| Pilot age | 31 |
| Pilot total time | 5,750 hrs · High time |
| Time in type | 130 hrs |
| Fatalities | 2 |
Probable cause
NTSB findings
- Personnel issues-Task performance-(general)-(general)-Pilot
- Personnel issues-Task performance-Planning/preparation-Performance calculations-Pilot
- Environmental issues-Physical environment-Terrain-Mountainous/hilly terrain-Contributed to outcome
- Environmental issues-Conditions/weather/phenomena-Temp/humidity/pressure-High density altitude-Contributed to outcome
What happened
The airplane departed on a visual flight rules cross-country flight from a high-elevation (9,078 ft mean sea level) airport. Automated dependent surveillance-broadcast (ADS-B) data showed that the airplane proceeded east into a box canyon with rising terrain. The data showed that, before entering the box canyon, the airplane did not climb toward the west, where there was lower terrain. The data also showed that the airplane was in a gradual climb for about 8 miles into the canyon and that the airplane then made a right turn to the south just before impacting terrain. No known radio distress calls were received from the pilot. The airplane wreckage showed evidence of a nearly vertical impact.
Postaccident examination found no preimpact anomalies with the airframe, engine, flight controls, and propeller. Flight control continuity was confirmed from the cockpit to all flight control surfaces.
The elevation of the accident site was 11,823 ft mean sea level. The surrounding terrain to the north, east, and south was higher than the accident site elevation, with peaks ranging from about 12,000 to 14,000 ft. In addition, the calculated density altitude in the area of the accident site was about 13,604 ft, which would have diminished the airplane’s climb performance. There was no significant turbulence in the area. Thus, the pilot likely turned the airplane toward higher terrain and into the box canyon before the airplane could gain enough altitude to traverse the high terrain, resulting in a loss of control.