# NTSB WPR12CA258: Stemme S10-VT, N921BR, Warner Springs, CA, June 12, 2012 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: June 12, 2012, 12:00 local (19:00 UTC) - Place: Warner Springs, CA - Coordinates: 33.284442, -116.67472 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.2844&lon=-116.6747&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report September 13, 2012 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: Federal Aviation Administration - NTSB case key (mKey): 83939 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR12CA258 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83939/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83939 - Page: https://openairdocs.org/ntsb/WPR12CA258 ## Probable cause The pilots’ failure to maintain directional control while landing in a gusting crosswind. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Wind: crosswind](https://openairdocs.org/ntsb-findings/03034040): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [All aircraft, 1,008 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Instructor/check pilot (probable cause); cases with it: [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. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot was undergoing a flight review in a glider. Before the flight review, the pilot had obtained several hours of instruction from the flight instructor. During the final phase of a normal approach and landing, the glider became unstable due to a left crosswind. The glider's left wing contacted the ground, which resulted in a ground loop. During the ground loop, the tail boom separated, the main landing gear collapsed, and the left wing was damaged. The pilot reported no preimpact mechanical malfunctions or failures that would have precluded normal operation. ## Factual narrative The pilot was undergoing a flight review in a glider. His flight review had expired several years prior to the accident. Prior to the flight review, he had obtained several hours of instruction from the certified flight instructor. During the final phase of a normal approach and landing, the glider became unstable due to a left crosswind. The glider's left wing contacted the ground which resulted in a ground loop. During the ground loop, the tail boom separated, the main landing gear collapsed, and the left wing was damaged. The pilot reported no preimpact mechanical malfunctions with the glider that would have precluded normal operation. ## Aircraft - Registration: N921BR (not matched to a registry record) - Reported make and model: STEMME GMBH & CO S10-VT - Category: Glider - Serial number: 11-028 - Airframe hours: 250 - Engines: Rotax 914 110 hp reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: George Klopfer - Registered owner: Fractional Flight LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, June 8, 2012, 8 hours before - Departed: CL35, Warner Springs, CA - Destination: CL35, Warner Springs, CA - Flight plan: Unknown - Airport: CL35, Warner Springs Gliderport, runway 26, 4,700 × 70 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 30; injuries: none; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review October 26, 2011; seat: right; flight hours: 6,000 total, 500 in this make and model, 75 in the last 90 days, 25 in the last 30 days, 4 in the last 24 hours - Pilot; age 62; injuries: none; private; airplane ratings: multi-engine land, single-engine land, single-engine sea; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review July 11, 2009; seat: left; flight hours: 1,252 total, 248 in this make and model, 782 as pilot in command, 6 in the last 90 days, 6 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 290° at 8 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 57 °F - Altimeter: 29.95 inHg - Observed at: RMN, 19 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 20120612011619A](https://openairdocs.org/incident/20120612011619A), Jun 12, 2012: Stemme Gmbh & Co S10-VT, Warner Springs, CA, Substantial damage. After carefully reviewing the factors surrounding this accident, the investigating inspector feels the major reason for this accident were the winds. The wind… ## Docket (2 files) The files NTSB released with the investigation on July 16, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83939. 3.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370920&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Photo 1. Glider (item 2, .PDF, 668 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370869&FileExtension=.PDF&FileName=Photo%201.%20Glider-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.