ERA11LA234 · LET L 33 SOLO

Witnesses observed the pilot completing a preflight examination of the glider and stated that the glider's initial tow off the ground was uneventful. However, witnesses and the pilot of the tow plane stated that shortly after the glider lifted off, it began to fly erratically back and forth on tow with the air brakes somewhat extended. The pilot did not respond to a radio call from the tow plane pilot advising him of the floating air brakes. Witnesses and the tow plane pilot observed the glider positioned low and to the left of the tow plane before it suddenly climbed up and to the right. The tow rope broke and the glider stalled then spun to the ground. No preexisting malfunctions or anomalies that would have precluded normal operation of the glider were noted. The floating air brakes were likely due to the pilot's failure to secure the handle before takeoff, but they should not have resulted in a loss of control and could have been easily corrected by the pilot. The pilot had recently successfully completed a flying club check ride, and the wind at the time of the accident was relatively light and should not have been a factor. The pilot's autopsy and toxicological results did not reveal any physiological issues that would have affected the flight. However, the glider's lack of mechanical anomalies, the benign weather conditions, and the pilot's recently-demonstrated flying abilities contrasted sharply with the glider's erratic flight path, the pilot's failure to correct a relatively easy air brake discrepancy, and his lack of response to a radio call. Therefore, it is likely that the pilot became incapacitated for unknown reasons just after takeoff.

Verbatim NTSB analysis and probable cause from the NTSB dataset