Schempp-Hirth DISCUS 2B N21TH accident near Bishop, California

Probable cause

The pilot’s exceedance of the glider’s critical angle of attack while maneuvering over rising mountainous terrain, which resulted in an aerodynamic stall.

NTSB analysis

The pilot of the glider reported that, while circling over rising mountainous terrain in search of thermals, he approached a "ridge right in front of me [him]." He added that, at that moment, "the [flight] controls went soft [and] I [he] could see that I [he] was [aerodynamically] stalled and plummeting toward the terrain and trees below." He further added that he "pointed the [glider's] nose down at a steep angle" to gain airspeed, but the glider impacted trees and steep terrain.

The fuselage and both wings sustained substantial damage.

The pilot reported that there were no preaccident mechanical malfunctions or failures with the glider that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for GAA17CA368 for the full record.