Amateur-built WOODSTOCK I N21468 accident near Decatur, Texas

Probable cause

The pilot's failure to maintain adequate airspeed while turning from the downwind to the base leg of the pattern in gusting wind conditions, which resulted in the glider exceeding its critical angle-of-attack and entering an aerodynamic stall/spin at a low altitude.

NTSB analysis

The pilot of the glider received a tow to altitude about 1430; about 30 minutes later, the glider was seen maneuvering between 3,000 and 4,000 ft several miles from the airport. When the glider did not return by sunset (civil twilight was 1926), it was reported missing, and the wreckage was subsequently located near the approach end of the runway several hours later. During postaccident examination, no preimpact anomalies with the glider were noted. The elevator trim was displaced, consistent with a nose-up trim setting or for slow airspeed. Impact damage, the orientation of the wreckage, and ground scar signatures were consistent with the glider being in a stall/spin before impact, on an approximate downwind-to-base leg of the traffic pattern. While the time of the accident is unknown, wind averaging about 12 knots with gusts to 18 knots, existed at the airport until about 1755. An autopsy found no evidence of medical impairment of the pilot. Although toxicological testing was positive for two medications that the pilot had previously reported to the Federal Aviation Administration, the presence of the medication was deemed not to pose a hazard to flight safety. The circumstances of the accident were consistent with the pilot's failure to maintain adequate airspeed and angle-of-attack as the glider turned from the downwind to the base leg of the traffic pattern, and the glider's subsequent stall/spin. It is possible that the gusting wind may have contributed to the pilot's failure to maintain control of the glider.

Text from the NTSB. Open the NTSB docket for CEN16LA007 for the full record.