Pilot Debrief

JONKER SAILPLANES JS1C near Cotulla, TX — 2019-08-07

Final reportCEN19FA253
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Date
2019-08-07
Location
Cotulla, TX, USA
Aircraft
JONKER SAILPLANES JS1C
Registration
N213DT
Category
Glider
Highest injury
Fatal
Fatalities
1

Probable cause

The pilot’s failure to maintain sufficient airspeed of the glider, which resulted in exceedance of the glider's critical angle of attack and an aerodynamic stall/spin.

NTSB narrative

The pilot was participating in a glider soaring competition and did not return from the flight. The wreckage of the glider was found about 7 miles from one of the turn points used during the competition. A ground impact scar was found beneath the glider's left wing and a few feet aft of the right wing. The glider's aft fuselage was fractured with the tail bent upward and to the left. The ground scar and fuselage damage are consistent with the glider impacting terrain in a near vertical attitude with rotation to the left at impact. Examination of the glider and its control system did not reveal any preimpact anomalies that would have precluded normal operation. Although the glider was equipped with a turbine sustainer engine, it was found retracted, which indicates that it was not in use at the time of the accident. The toxicological tests performed on the pilot’s remains were positive for ethanol, delta-9-tetrahydrocannabinol (THC), and carboxy-delta-9-THC (THC-COOH). The ethanol was likely the result of putrefaction. While the psychoactive effects may last a few hours, THC can be detected in the body for days or weeks. Thus, test results do not necessarily reflect recent use and cannot be used to prove that the user was under the influence of the drug at the time of testing. Based on the available evidence, it is likely that the pilot did not maintain sufficient airspeed of the glider, which resulted in exceedance of the glider's critical angle of attack and an aerodynamic stall/spin.

Analysis

Primary failure mode
Human factors
First missed decision gate
Pilot's decision to fly under the influence of impairing substances.

NTSB coding

Evidence available

  • ADS-B / radar
  • Photos
  • 6 docket documents
View NTSB final reportView NTSB docket

Docket documents6

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