Schempp Hirth STANDARD CIRRUS N271BL accident near Groveland, Florida

Probable cause

The pilot’s exceedance of the glider’s critical angle of attack following his premature termination of the tow for reasons that could not be determined, which resulted in an aerodynamic stall/spin during a turn back to the departure airport.

NTSB analysis

According to the tow pilot, while climbing through about 500 ft above the ground during takeoff, they encountered an area of turbulence and the glider got “low on the tow” and out of view in his mirror. He then felt the glider release from the tow. Witnesses stated that the glider released from the tow at "low" altitude and turned back toward the gliderport when the nose of the glider pointed “down," and the glider descended vertically from view.

Examination of the wreckage confirmed continuity to all flight control surfaces and revealed no preimpact mechanical anomalies.

Review of the pilot’s logbook revealed a total of 49 flights. Of those flights, 44 were performed in two-seat gliders. The pilot had recorded five flights in the accident glider, all of which included an aerotow to a release altitude of either 2,500 or 3,000 ft agl. There was no evidence to indicate that the pilot had performed any simulated takeoff emergencies in the accident glider make and model.

A number of different mechanical, operational, and environmental factors can result in an early termination of a tow; however, the reason the pilot terminated the tow could not be determined based on available evidence. Witness descriptions of the glider’s flight after release are consistent with the pilot exceeding the critical angle of attack while maneuvering toward the runway, which resulted in an aerodynamic stall.

Text from the NTSB. Open the NTSB docket for ERA20LA145 for the full record.