Schweizer SGS126 N65968 accident near Moscow, Tennessee

Probable cause

The pilot's failure to maintain adequate airspeed and his exceedance of the glider’s critical angle of attack while maneuvering at low altitude, which resulted in an aerodynamic stall/spin.

NTSB analysis

A tow plane pilot on the ground reported that he watched the glider fly for about 20 minutes after it was released from the tow plane. After the glider turned onto the left downwind approach to land and while about 300 ft above ground level (agl), he saw the glider enter a right 360° turn while on the base leg, followed shortly after by a 180° right turn. The glider then entered an aerodynamic stall/spin from about 100 ft agl and descended into trees. Although the glider pilot stated that he was unable to recall the sequence of events that occurred after entering the traffic pattern, he did not believe that there were any mechanical anomalies with the glider that would have precluded normal operation. It is likely that the pilot did not maintain adequate airspeed and exceeded the glider's critical angle of attack, which resulted in the aerodynamic stall/spin.

Text from the NTSB. Open the NTSB docket for ERA17LA048 for the full record.