# NTSB GAA17CA368: Schempp-Hirth Discus 2B, N21TH, Bishop, CA, June 22, 2017 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Data collection · Final report - Date: June 22, 2017, 13:00 local (20:00 UTC) - Place: Bishop, CA - Coordinates: 37.436389, -118.261108 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=37.4364&lon=-118.2611&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report October 17, 2017 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA/ FSDO - NTSB case key (mKey): 95441 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA17CA368 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95441/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95441 - Page: https://openairdocs.org/ntsb/GAA17CA368 ## Probable cause The pilot’s exceedance of the glider’s critical angle of attack while maneuvering over rising mountainous terrain, which resulted in an aerodynamic stall. ## 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: [Schempp-Hirth DISCUS-2B, 3 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=3801904), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Capability exceeded (probable cause); cases with it: [Schempp-Hirth DISCUS-2B, 1 case](https://openairdocs.org/ntsb-findings/01062042/cases.md?model=3801904), [All aircraft, 990 cases](https://openairdocs.org/ntsb-findings/01062042/cases.md) - [Terrain: mountainous/hilly terrain](https://openairdocs.org/ntsb-findings/03021010): Environmental issues › Physical environment · Contributed to outcome; cases with it: [Schempp-Hirth DISCUS-2B, 1 case](https://openairdocs.org/ntsb-findings/03021010/cases.md?model=3801904), [All aircraft, 329 cases](https://openairdocs.org/ntsb-findings/03021010/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering: Loss of lift](https://openairdocs.org/ntsb-events/500); cases with it: [Schempp-Hirth DISCUS-2B, 1 case](https://openairdocs.org/ntsb-events/500/sequence.md?model=3801904), [All aircraft, 252 cases](https://openairdocs.org/ntsb-events/500/sequence.md) - [Maneuvering: Aerodynamic stall/spin](https://openairdocs.org/ntsb-events/241); cases with it: [Schempp-Hirth DISCUS-2B, 1 case](https://openairdocs.org/ntsb-events/241/sequence.md?model=3801904), [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) (defining event); cases with it: [Schempp-Hirth DISCUS-2B, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=3801904), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Schempp-Hirth DISCUS-2B, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=3801904), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot of the glider reported that, while circling over rising mountainous terrain in search of thermals, he approached a "ridge right in front of me [him]." He added that, at that moment, "the [flight] controls went soft [and] I [he] could see that I [he] was [aerodynamically] stalled and plummeting toward the terrain and trees below." He further added that he "pointed the [glider's] nose down at a steep angle" to gain airspeed, but the glider impacted trees and steep terrain. The fuselage and both wings sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the glider that would have precluded normal operation. ## Factual narrative The pilot of the glider reported that, while circling over rising mountainous terrain in search of thermals, he approached a "ridge right in front of me [him]." He added that, at that moment, "the [flight] controls went soft [and] I [he] could see that I [he] was [aerodynamically] stalled and plummeting toward the terrain and trees below." He further added that, he "pointed the [glider's] nose down at a steep angle" to gain airspeed, but the glider impacted trees and steep terrain. The fuselage and both wings sustained substantial damage. The pilot reported that there were no preaccident mechanical malfunctions or failures with the glider that would have precluded normal operation. ## Aircraft - Registration: [N21TH](https://openairdocs.org/deregistered/N21TH-2020-09-04), registration cancelled 2020-09-04, S/N 91, built 2001 (OpenAirDocs) - Reported make and model: SCHEMPP-HIRTH DISCUS 2B (NO SERIES) - Registry model: [Schempp-Hirth DISCUS-2B](https://openairdocs.org/model/schempp-hirth-discus-2b) (registry code 3801904) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 91 - Year built: 2001 - Engines: none - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Bay Area Soaring Associates Inc. - Registered owner: Bay Area Soaring Associates Inc. - Airworthiness certificate: Special, Experimental (Special) - Last inspection: Annual, March 11, 2017 - Departed: BIH, BISHOP, CA - Destination: BIH, BISHOP, CA - Equipment: Handheld GPS, Satellite tracking device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: minor; private; airplane ratings: single-engine land; last flight review February 5, 2017; seat: single; restraint: 4-point; flight hours: 394 total, 1 in this make and model, 374 as pilot in command, 22 in the last 90 days, 13 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 100 °F, dew point 28 °F - Altimeter: 29.90 inHg - Observed at: KBIH, 30 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 20170622010859A](https://openairdocs.org/incident/20170622010859A), Jun 22, 2017: Schempp-Hirth DISCUS-2B, Bishop, CA, Substantial damage. Pilot inexperience with this glider and misjudgement of available thermal or ridge lift available resulting in contact with trees and then terrain. This… ## Docket (3 files) The files NTSB released with the investigation on September 18, 2017, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95441. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 834 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40456210&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Pilot Statement (item 2, .PDF, 49 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40456211&FileExtension=.PDF&FileName=Pilot%20Statement-Master.PDF - Accident Photo (Courtesy of Operator) (item 3, .PDF, 1 photo, 222 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40456212&FileExtension=.PDF&FileName=Accident%20Photo%20(Courtesy%20of%20Operator)-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.