# NTSB CEN19FA253: Jonker Sailplanes JS1C, N213DT, Cotulla, TX, August 7, 2019 - Type: NTSB accident investigation - Classification: Accident · Fatal · Class 3 · Field · Final report - Date: August 7, 2019, 15:30 local (20:30 UTC) - Place: Cotulla, TX - Coordinates: 28.409999, -99.078056 - Nearby events: https://openairdocs.org/map.md?lat=28.4100&lon=-99.0781&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA - San Antonio FSDO - NTSB case key (mKey): 100010 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19FA253 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100010/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100010 - Page: https://openairdocs.org/ntsb/CEN19FA253 ## 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. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Jonker Sailplanes JS1-C, 1 case](https://openairdocs.org/ntsb-findings/01062010/cases.md?model=056321V), [All aircraft, 1,681 cases](https://openairdocs.org/ntsb-findings/01062010/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Jonker Sailplanes JS1-C, 3 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=056321V), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241) (defining event); cases with it: [Jonker Sailplanes JS1-C, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=056321V), [All aircraft, 1,529 cases](https://openairdocs.org/ntsb-events/241/sequence.md) - [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Jonker Sailplanes JS1-C, 3 cases](https://openairdocs.org/ntsb-events/240/sequence.md?model=056321V), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Jonker Sailplanes JS1-C, 3 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=056321V), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis 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. ## Factual narrative On August 6, 2019, about 1530 central daylight time, a Jonker JS-1C glider, N213DT, was destroyed when it was involved in an accident near Cotulla, Texas. The pilot was fatally injured. The glider was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The flight originated from the Garner Field Airport (UVA), near Uvalde, Texas, about 1330. The pilot was participating in the 2019 Uvalde Invitational and was flying a cross-country course that included three turn points. The glider was to depart Garner Field Airport (UVA), Uvalde, Texas; fly to turn-point locations near Cotulla, Texas, Catarina, Texas, and Eagle Pass, Texas; and return to UVA. When the pilot did not return to UVA and could not be reached via radio by the competition coordinators, a search was started. The wreckage of the glider was found about 7 nautical miles east-southeast of Cotulla-La Salle County Airport (COT), Cotulla, Texas. According to the Webb County Medical Examiner, Laredo, Texas, autopsy report, the cause of death of the pilot was multiple blunt force and crushing injuries and the manner of death was accident. The exam was limited by extensive injuries; no contributory natural disease was identified by the medical examiner. Toxicology testing performed by the Federal Aviation Administration Forensic Sciences Laboratory detected ethanol in the pilot's liver and muscle tissue at 0.048 grams per hectogram (gm/hg) and 0.144 gm/hg, respectively. N-propanol was also detected in liver and muscle tissue; the tissue samples were noted to have putrefaction. Toxicology testing detected marijuana's primary psychoactive chemical delta-9-tetrahydrocannabinol (THC) in the pilot's muscle and kidney tissue but not in liver or lung tissue. The THC inactive metabolite carboxy-delta-9-THC (THC-COOH) was detected in the pilot's liver and kidney tissue but was not detected in muscle or lung tissue. Ethanol is a social drug commonly consumed by drinking beer, wine, or liquor. It acts as a central nervous system depressant; it impairs judgment, psychomotor functioning, and vigilance. Ethanol is water soluble, and after absorption it quickly and uniformly distributes throughout the body's tissues and fluids. The distribution pattern parallels water content and blood supply of the tissue. A small amount of ethanol can be produced after death by microbial activity, usually in conjunction with other alcohols, such as propanol. The marijuana plant (Cannabis sativa) contains chemicals called cannabinoids; THC is the primary psychoactive cannabinoid compound. THC's mood-altering effects include euphoria and relaxation. In addition, marijuana causes alterations in motor behavior, time and space perception, and cognition. Significant performance impairments are usually observed for at least 1-2 hours after marijuana use, and residual effects have been reported up to 24 hours. THC is rapidly metabolized, but the rate of metabolism is not linear and depends on the means ofingestion (smoking, oil, and edibles), potency of the product, frequency of use, and user characteristics. The primary metabolite, 11-hydroxy-delta-9-THC, is equally psychoactive but is rapidly metabolized to the nonpsychoactive metabolite THC-COOH. THC is fat soluble, so it is stored in fatty tissues and can be released back into the blood long after consumption. 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. An LxNav model LX9070 datalogger was retrieved from the glider wreckage and examined in the National Transportation Safety Board Vehicle Recorder Division. The examination revealed that historical flight track data was stored on an internal micro-SD card. Extraction of the data from the card was not possible due to impact damage. The glider impacted a level field with the entire airframe located in the immediate vicinity of the wreckage. A linear ground scar consistent with wing impact was observed with the left wing of the glider directly over the ground scar and the right wing located a few feet forward of the ground scar. The glider's aft fuselage was fractured, and the tail was bent upward and to the left relative to the fuselage. The four-piece wing spar was intact from tip to tip. The leading edge of the wing exhibited crushing damage along the entire span. The fuselage was crushed rearward from the nose to aft of the wing. The glider was equipped with a turbine sustainer engine that could be retracted into the fuselage when not in use; the engine was found retracted within the fuselage. Examination of the glider and its control system did not reveal any preimpact anomalies. ## Aircraft - Registration: [N213DT](https://openairdocs.org/deregistered/N213DT-2020-06-01), registration cancelled 2020-06-01, S/N 1C-066, built 2014 (OpenAirDocs) - Reported make and model: JONKER SAILPLANES JS1C - Registry model: [Jonker Sailplanes JS1-C](https://openairdocs.org/model/jonker-sailplanes-js1-c) (registry code 056321V) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 1C-066 - Year built: 2014 - Damage: Destroyed - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Departed: UVA, Uvalde, TX - Destination: UVA, Uvalde, TX ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 33; injuries: fatal; private; medical: class 3, without waivers/limitations; seat: single; restraint: 4-point; toxicology performed; flight hours: 500 total ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 102 °F, dew point 61 °F - Altimeter: 29.85 inHg - Observed at: COT, 7 nm away ## Docket (6 files) The files NTSB released with the investigation on March 9, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100010. 2.8 MB in all. - Toxicological report (item 1, PDF, 1 page, 672 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9922212&FileExtension=pdf&FileName=Tox%20report%20-%20Pilot_Redacted-Rel.pdf - Weather information (item 2, PDF, 12 pages, 166 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9921633&FileExtension=pdf&FileName=Weather%20information-Rel.pdf - Data from spot GPS tracker (item 3, CSV, 335 B): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9921297&FileExtension=csv&FileName=Spot%20tracker%20data-Rel.csv - Accident site photos (item 4, PDF, 6 pages, 943 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9927506&FileExtension=pdf&FileName=CEN19FA253%20-%20Photos-Rel.pdf - Evidence control form (item 5, PDF, 2 pages, 82 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9928410&FileExtension=pdf&FileName=Evidence%20Control%20Form%20(LXNAV)%20and%20Disposition_Redacted-Rel.pdf - Recorder laboratory e-mail report for lxnav (item 6, PDF, 4 pages, 903 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=9928288&FileExtension=pdf&FileName=Recorder%20Lab%20E-mail%20Report-Rel.pdf From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.