Socata TB 20 TRINIDAD N28070 accident near Sierraville, California

Probable cause

The pilot's decision to continue visual flight rules flight into instrument meteorological conditions, which resulted in controlled flight into mountainous terrain.

NTSB analysis

The noninstrument-rated private pilot was making a visual flight rules (VFR) cross-country flight in the airplane over mountainous terrain. Radar data revealed that the airplane initially flew in a northerly direction after takeoff and then turned west toward the destination; this route was consistent with a route the pilot had followed on previous flights. About 17 minutes after takeoff, the airplane was about 19 nautical miles (nm) northwest of the departure airport. The last radar return, which occurred about 18 minutes after takeoff, showed that the airplane was about 20 nautical miles (nm) northwest of the departure airport and about 0.47 nm southeast of the accident site on a southwesterly heading at an altitude of 8,869 ft mean sea level (msl). Shortly thereafter, the airplane impacted remote, snow-covered, mountainous terrain on a northerly heading at an elevation of 7,697 ft msl. The changes in heading and altitude between the last radar return and the impact suggest that the pilot began maneuvering the airplane after radar contact was lost. A survey of the accident site revealed a linear debris path and damage to the airplane that were consistent with controlled flight into terrain. Examination of the airframe and engine did not reveal evidence of any mechanical anomalies that would have precluded normal operation.

Review of weather information strongly suggests that clouds, light rain, snow, or mixed precipitation was falling and instrument meteorological conditions (IMC) likely existed in the accident area. It is likely that the pilot encountered IMC conditions and was maneuvering in an attempt to return to VFR flight when the airplane collided with terrain.

Text from the NTSB. Open the NTSB docket for WPR17FA105 for the full record.