Amateur-built ARCUS accident near Ephraim, Utah, July 1, 2019

The NTSB's narrative final · quoted from the NTSB record

The pilot and passenger onboard the glider was participating in a soaring competition. Data from an onboard flight recorder were consistent with the pilot climbing in various areas of thermal lift, reaching a peak altitude of 6,935 ft above ground level about 50 minutes into the flight. During the subsequent approximate 30 minutes of the flight, the glider proceeded south southwesterly along a ridgeline, circling several times in different locations, but the glider continued to descend. Data indicated that the glider was in a right turn about 185 ft above terrain before it impacted a tree. Postaccident examination revealed no evidence of mechanical malfunctions or anomalies that would have precluded normal operation. Review of weather information indicated a conditionally unstable environment and likely thermal lift in the area, though satellite imagery depicted clear skies over the immediate area of the accident site, with fair weather cumulus clouds located east of the site. Wind conditions in the area of the accident site were likely insufficient to provide orographic lift. The pilot’s maneuvering in close proximity to terrain was consistent with his attempt to obtain or remain in an area of lift; it is possible that the glider may have encountered adverse wind that resulted in a loss of control at an altitude too low for recovery, or that the pilot initiated a 360° turn at an inadequate distance from terrain.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.