Burkhart Grob G-103A TWIN II ACRO accident near Warner Springs, California, November 26, 2010
On November 26, 2010 at about 8:55 pm local time, a Burkhart Grob G-103A TWIN II ACRO (glider), registered N855BG, was substantially damaged in an accident during landing near Warner Springs, California (Warner Springs Gliderport airport). It was an instructional flight under general aviation rules (Part 91). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The certified flight instructor's inadequate compensation for the crosswind and delayed remedial action during landing, which resulted in a ground loop.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- November 26, 2010 · about 8:55 pm local time · cases in 2010
- Place
- Warner Springs, California · Warner Springs Gliderport · cases near this airport · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Burkhart Grob G-103A TWIN II ACRO · all G-103A TWIN II ACROs on the register
- Registration
- N855BG · no longer on the register · serial 34017-K-249
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The certified flight instructor (CFI) stated that he was providing instruction to a student pilot in a glider. After a routine local instructional flight, they returned to the departure airport for landing. The student was flying the glider and the CFI was providing verbal instructions to him as they completed a standard traffic pattern to the dirt landing area. He reported that there was a crosswind at 12 knots, gusting to about 20 knots. The glider encountered a high sink rate and the CFI took authority over the controls. The glider ground looped, resulting in substantial damage to the tail. The CFI reported no preimpact mechanical malfunctions or failures with the glider that would have precluded normal operation.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Loss of control on ground during landing defining event
The NTSB's findings
- cause Environmental issues › Conditions/weather/phenomena › Wind › Crosswind › Response/compensation
- cause Personnel issues › Action/decision › Action › Delayed action › Instructor/check pilot
- Environmental issues › Conditions/weather/phenomena › Wind › Crosswind › Effect on operation
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Directional control › Not attained/maintained
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: single-engine land; instructor: glider; rotorcraft: glider
- Flight time: 10,260 hours in all; 2,000 in this make and model; 80 in the last 90 days; 10,190 as pilot in command
- Last flight review: December 30, 2008
- Medical certificate: Class 3 (with waivers/limitations)
- Injury: no injuries
Dual student
- Medical certificate: None
- Seat: frt
- Injury: no injuries
The aircraft
- Airframe total time: 7,248 hours
- Last inspection: annual inspection, August 4, 2010
- Maximum gross weight: 1,279 lb
- Seats: 2
- Landing gear: fixed
- Operator: Sky Sailing INC
The flight
- Departed from: CL35 Warner Springs CA at 8:27 pm
- Destination: CL35 Warner Springs CA
- Flight plan: none
- Runway 08, 4,700 ft by 70 ft
Weather at the time
- Light: daylight
- Wind: from 300° at 8 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 21°F (-6°C)
- Altimeter: 30.12 inHg
- Observation at 8:53 pm from RNM, 19 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
2 documents, released by the NTSB on December 20, 2010. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 9 pages | View Download |
| 2 | Photo 1. Glider | PDF, 1 page | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Connections how this case links to the rest of the register
- N855BG: not on the register today · the record of its deregistration
- Burkhart Grob G-103 71 registered today · the model family and its accident history
- Burkhart Grob 99 aircraft on the register
- Warner Springs · nearest airport
- Accidents and incidents in California 9,080 since 1982 · 1,096 in the last ten years
- California 28,279 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/WPR11CA060.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.