What happened
The flight was proceeding northeast toward Mount Yeckel when the aircraft encountered significant wind shear and downdrafts. According to the pilot's report, these atmospheric conditions forced the aircraft into nearby trees. The accident took place while the aircraft was flying over rising terrain within a canyon area at an elevation of approximately 11,000 feet.
The investigation
Analysis of the environmental conditions indicated that the computed density altitude was 12,500 feet. This high density altitude significantly impacted the aircraft's performance capabilities during the critical phase of flight over the mountainous terrain.
Findings
The primary factors contributing to this accident included the encounter with wind shear and downdrafts in a high-elevation environment. The pilot was operating at an elevation of about 11,000 feet with a computed density altitude of 12,500 feet. According to the operator's manual, the predicted rate of climb for that specific altitude was only 257 feet per minute, which likely limited the aircraft's ability to maintain altitude or escape the deteriorating weather conditions.
Safety message
Pilots operating in mountainous terrain must carefully consider density altitude and its impact on climb performance. High density altitudes can severely reduce an aircraft's ability to gain altitude, making it difficult to avoid terrain when encountering unexpected wind shear or downdrafts.