# NTSB LAX99LA285: Burkhart Grob G 103 Twin II, N8013K, Llano, CA, August 23, 1999 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: August 23, 1999, 15:10 local (22:10 UTC) - Place: Llano, CA - Coordinates: 34.490081, -117.770576 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=34.4901&lon=-117.7706&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 14, 2001 - Report: Approved by Office Director - NTSB case key (mKey): 47233 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX99LA285 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/47233/pdf - Page: https://openairdocs.org/ntsb/LAX99LA285 ## Probable cause The pilot's encounter with a sudden and violent dust devil, which caused the student pilot to lose control of the aircraft during the landing flare/touchdown. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, landing - flare/touchdown - weather condition - dust devil/whirlwind (cause) - weather condition - updraft (cause) - aircraft control - not possible, pilot in command - Hard landing, descent - uncontrolled - stall - encountered, pilot in command - aircraft control - not possible, pilot in command (cause) - On ground/water encounter with terrain/water, landing - flare/touchdown - ground loop/swerve - encountered, pilot in command ## Analysis As the student pilot began his landing flare approximately 10 feet above the runway surface, he observed a dust devil move onto the runway directly in front of him. He applied down elevator control but the glider ascended about 50 feet above the ground into the dust devil. The glider stalled and landed hard on the runway, then ground looped. Ground witnesses observed a 'large and violent dust devil' touching down on the runway in the path of the landing glider just as it was in the landing flare. ## Factual narrative On August 23, 1999, at 1510 hours Pacific daylight time, a Burkhart Grob G 103 Twin II, N8013K, landed hard after encountering a dust devil while landing at the Crystal Gliderport in Llano, California. The glider, operated by Great Western Soaring School, Llano, was substantially damaged. The student glider pilot, who held a private pilot certificate with an airplane single engine land rating, was not injured. The local area instructional flight was conducted under the provisions of 14 CFR Part 91 and had originated from the Crystal Gliderport at 1349. Visual meteorological conditions prevailed and no flight plan was filed. The pilot reported that he was preparing to land on runway 25, and that the tetrahedron indicated the wind was coming straight down the runway. As he was flaring approximately 10 feet above the runway surface, he observed a dust devil move onto the runway directly in front of him. He applied down elevator control but the glider ascended about 50 feet above the ground into the dust devil. The pilot stated that the glider stalled and landed hard on the runway numbers. The glider's right wing tip caught on the ground and the glider ground looped 180 degrees on the runway. During this process, the empennage broke off at the aft fuselage boom just forward of the fin. The tail wheel and nose wheel tires blew out. Ground witnesses provided statements that were consistent in the observation that a "large and violent dust devil" touched down on the runway in the path of the landing glider just as it was in the landing flare. ## Aircraft - Registration: [N8013K](https://openairdocs.org/aircraft/N8013K), registered now, S/N 3702, built 1982 (OpenAirDocs) - Reported make and model: Burkhart Grob G 103 TWIN II (G 103 TWIN) - Registry model: [Burkhart Grob G 103 TWIN II](https://openairdocs.org/model/burkhart-grob-g-103-twin-ii) (registry code 1660203) (OpenAirDocs) - Registry engine: [NONE](https://openairdocs.org/engine/none) (registry code 00000, none) (OpenAirDocs) - Category: Glider - Serial number: 3702 - Airframe hours: 884 - Engines: unknown - Damage: Substantial damage - Flight: Instructional, Part 91 - Operator: Great Western Soaring School - Registered owner: Douglas Turner - Airworthiness certificate: Standard, Normal - Last inspection: Annual, July 5, 1999, 84 hours before - Departed: L01 - Airport: L01, Crystal Gliderport, runway 25, 4,500 × 250 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 43; private; airplane ratings: single-engine land; seat: front; flight hours: 136 total, 13 in this make and model, 28 as pilot in command, 13 in the last 90 days, 12 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 250° at 21 knots, gusting 25 - Visibility: 10 statute miles - Temperature: 99 °F, dew point 50 °F - Altimeter: 29.00 inHg - Observed at: PMD, 16 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 19990823025569A](https://openairdocs.org/incident/19990823025569A), Aug 23, 1999: Grob G103ATWIN2, Llano, CA, Substantial damage. (.19) On August 23, 1999, at 1510 hours pacific daylight time, a burkhart Grob g 103 twin ii, N8013K, landed hard after encountering a dust devil at the… 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.