# NTSB GAA15CA172: Schweizer SGS 1 26B, N5839V, Silver Springs, NV, July 8, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 8, 2015, 15:00 local (22:00 UTC) - Place: Silver Springs, NV - Coordinates: 39.404998, -119.251945 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.4050&lon=-119.2519&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: No injuries - Injuries: 1 uninjured - Status: Completed, report September 30, 2015 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: Federal Aviation Administration - NTSB case key (mKey): 91529 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA15CA172 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91529/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91529 - Page: https://openairdocs.org/ntsb/GAA15CA172 ## Probable cause The pilot's improper decision making in adverse weather conditions, which resulted in an encounter with weather and impact with terrain. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Schweizer SGS 1-26B, 2 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=8050118), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Performance/control parameters: descent/approach/glide path](https://openairdocs.org/ntsb-findings/01062040): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Schweizer SGS 1-26B, 4 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md?model=8050118), [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/01062040/cases.md) - [Convective weather: thunderstorm](https://openairdocs.org/ntsb-findings/03033010): Environmental issues › Conditions/weather/phenomena · Decision related to condition; cases with it: [Schweizer SGS 1-26B, 1 case](https://openairdocs.org/ntsb-findings/03033010/cases.md?model=8050118), [All aircraft, 100 cases](https://openairdocs.org/ntsb-findings/03033010/cases.md) - [Terrain: rough terrain](https://openairdocs.org/ntsb-findings/03021015): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Schweizer SGS 1-26B, 1 case](https://openairdocs.org/ntsb-findings/03021015/cases.md?model=8050118), [All aircraft, 442 cases](https://openairdocs.org/ntsb-findings/03021015/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: [Schweizer SGS 1-26B, 1 case](https://openairdocs.org/ntsb-events/390/sequence.md?model=8050118), [All aircraft, 224 cases](https://openairdocs.org/ntsb-events/390/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Schweizer SGS 1-26B, 2 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=8050118), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Schweizer SGS 1-26B, 4 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=8050118), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot of the glider reported diverting from his original destination to an alternate airport due to an approaching thunderstorm from the west that he could see. The pilot chose to stay aloft to see which direction the weather was moving. When the thunderstorm started moving east toward the pilot he decided to land. The pilot reported that while he was on final approach for the runway, he was hit by a gust front, the wind shifted and he was blown to the north side of the runway and landed on a dirt road. During the landing roll the glider impacted a fence post and sustained substantial damage to the fuselage and right wing. A review of local weather data showed nearby convective activity capable of producing significant convective gust fronts. The thunderstorm hazard was forecasted by the National Weather Service prior to the flight, which included a special weather statement for the accident area advising that strong outflow gusts up to 50 miles per hour were possible. The pilot reported receiving a weather forecast the morning of the flight that included the possibility for afternoon thunderstorms. The pilot reported no preimpact mechanical failures or malfunctions with the glider that would have precluded normal operation. ## Factual narrative The pilot of the glider reported diverting from his original destination to an alternate airport due to an approaching thunderstorm from the west that he could see. The pilot chose to stay aloft to see which direction the weather was moving. When the thunderstorm started moving east toward the pilot he decided to land. The pilot reported that while he was on final approach for the runway, he was hit by a gust front, the wind shifted and he was blown to the north side of the runway and landed on a dirt road. During the landing roll the glider impacted a fence post and sustained substantial damage to the fuselage and right wing. A review of local weather data showed nearby convective activity capable of producing significant convective gust fronts. The thunderstorm hazard was forecasted by the National Weather Service prior to the flight, which included a special weather statement for the accident area advising that strong outflow gusts up to 50 miles per hour were possible. The pilot reported receiving a weather forecast the morning of the flight that included the possibility for afternoon thunderstorms. The pilot reported no preimpact mechanical failures or malfunctions with the glider that would have precluded normal operation. ## Aircraft - Registration: [N5839V](https://openairdocs.org/aircraft/N5839V), registered now, S/N 272, built 1964 (OpenAirDocs) - Reported make and model: SCHWEIZER SGS 1 26B (B) - Registry model: [Schweizer SGS 1-26B](https://openairdocs.org/model/schweizer-sgs-1-26b) (registry code 8050118) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 272 - Year built: 1964 - Airframe hours: 479 - Damage: Substantial damage - Flight: Air race/show, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 5, 2015 - Departed: MEV, MINDEN, NV - Destination: MEV, MINDEN, NV - Airport: SPZ, Silver Springs, runway 23, 6,001 × 75 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 70; injuries: none; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review June 30, 2014; seat: single; restraint: 4-point; flight hours: 4,746 total, 44 in this make and model, 4,652 as pilot in command, 54 in the last 90 days, 28 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 19 knots, gusting 35 - Visibility: 10 statute miles - Lowest ceiling: 8,000 ft broken - Temperature: 72 °F, dew point 48 °F - Altimeter: 29.87 inHg - Observed at: KRNO, 25 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 20150708011789A](https://openairdocs.org/incident/20150708011789A), Jul 8, 2015: Schweizer SGS 1-26B, Silver Springs, NV, Substantial damage. On 7-8-2015 the pilot participated in a glider competition at kmev. Pilot departed at 12:30 pm with clear weather. Approximately 2 hours later the pilot… ## Docket (3 files) The files NTSB released with the investigation on September 14, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91529. 7.7 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 645 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40431209&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Weather Study (item 2, .PDF, 6.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40431210&FileExtension=.PDF&FileName=Weather%20Study-Master.PDF - Photo 1 – Glider (Courtesy of FAA) (item 3, .PDF, 525 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40431211&FileExtension=.PDF&FileName=Photo%201%20%E2%80%93%20Glider%20(Courtesy%20of%20FAA)-Master.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.