# NTSB WPR14CA292: Jonker Sailplanes JS1-C, N501WG, Truckee, CA, July 14, 2014 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Data collection · Final report - Date: July 13, 2014, 17:23 local (Jul 14, 2014, 00:23 UTC) - Place: Truckee, CA - Coordinates: 39.326389, -120.130554 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.3264&lon=-120.1306&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report October 27, 2014 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 89658 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR14CA292 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/89658/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=89658 - Page: https://openairdocs.org/ntsb/WPR14CA292 ## Probable cause The pilot's failure to maintain aircraft control in gusting wind conditions while on final approach to the runway. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [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) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation; cases with it: [Jonker Sailplanes JS1-C, 1 case](https://openairdocs.org/ntsb-findings/03034045/cases.md?model=056321V), [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Jonker Sailplanes JS1-C, 2 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=056321V), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) (defining event); cases with it: [Jonker Sailplanes JS1-C, 1 case](https://openairdocs.org/ntsb-events/390/sequence.md?model=056321V), [All aircraft, 224 cases](https://openairdocs.org/ntsb-events/390/sequence.md) - [Approach-VFR pattern final: 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) - [Approach-VFR pattern final: 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 reported that following an uneventful flight, he checked the weather at his destination airport, noting wind was from 220 degrees at 7 knots, gusting to 16 knots. The pilot initiated an approach to landing on runway 20, however, while on final approach, the glider began to descend rapidly and roll to the left. The pilot applied opposite control inputs and noted that the glider began to turn to the right prior to impacting terrain slightly downslope from the runway. Recorded weather observations at the airport about 23 minutes after the accident revealed that the wind was from 250 degrees at 11 knots, gusting to 18 knots. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. ## Factual narrative The pilot reported that following an uneventful flight, he checked the weather at his destination airport, noting wind was from 220 degrees at 7 knots, gusting to 16 knots. The pilot initiated an approach to landing on runway 20, however, while on final approach, the glider began to descend rapidly and roll to the left. The pilot applied opposite control inputs and noted that the glider began to turn to the right prior to impacting terrain slightly downslope from the runway. Recorded weather observations at the airport about 23 minutes after the accident revealed that the wind was from 250 degrees at 11 knots, gusting to 18 knots. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N501WG](https://openairdocs.org/deregistered/N501WG-2015-05-15), registration cancelled 2015-05-15, S/N 1C-050, built 2013 (OpenAirDocs) - Reported make and model: JONKER SAILPLANES (PTY) LTD JS1-C (NO SERIES) - Registry model: [Jonker Sailplanes JS1-C](https://openairdocs.org/model/jonker-sailplanes-js1-c) (registry code 056321V) (OpenAirDocs) - Registry engine: [Amateur-built UNKNOWN ENG](https://openairdocs.org/engine/amateur-built-unknown-eng) (registry code 99999) (OpenAirDocs) - Category: Glider - Serial number: 1C-050 - Year built: 2013 - Airframe hours: 130 - Engines: M&D Flugzeugbau TJ42 85 lbs thrust turbo jet - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Continuous airworthiness, September 2, 2013 - Departed: TRK, Truckee, CA - Destination: TRK, Truckee, CA - Airport: TRK, Truckee-Tahoe, runway 20, 4,650 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 63; injuries: serious; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 19, 2013; seat: center; restraint: 4-point; flight hours: 5,000 total, 139 in this make and model, 11 in the last 90 days, 9 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 11 knots, gusting 18 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F, dew point 43 °F - Altimeter: 30.25 inHg - Observed at: KTRK, 1 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20140713013109A](https://openairdocs.org/incident/20140713013109A), Jul 13, 2014: Jonker Sailplanes (Pty) Ltd JS1-C, Truckee, CA, Substantial damage. During landing on runway 19 after a five hour flight, the pilot entered the traffic pattern on a left down wind approach. The down wing leg of the approach was… ## Docket (2 files) The files NTSB released with the investigation on October 20, 2014, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=89658. 1.4 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40417804&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Witness Statement (item 2, .PDF, 368 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40417805&FileExtension=.PDF&FileName=Witness%20Statement-Redacted.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.