Burkhart Grob G103C TWIN III ACRO accident near Gregory, Michigan, June 14, 2009
On June 14, 2009 at about 3:20 pm local time, a Burkhart Grob G103C TWIN III ACRO (glider), registered N103MS, was substantially damaged in an accident during maneuvering near Gregory, Michigan (Richmond Field). It was a glider-towing flight under general aviation rules (Part 91). 1 person was killed and 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain sufficient airspeed during the turn to return for landing, which resulted an inadvertent stall/spin. Contributing to the accident was the failure of the ground winch tow cable shortly after takeoff.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 14, 2009 · about 3:20 pm local time · cases in 2009
- Place
- Gregory, Michigan · Richmond Field · cases near this airport · map
- Type
- Accident
- Injuries
- 1 person was killed and 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Burkhart Grob G103C TWIN III ACRO · all G103C TWIN III ACROs on the register
- Registration
- N103MS · registry record · serial 34156
- Damage
- Substantial damage
- Flight
- Glider-towing flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot reported that the takeoff and climb were normal during the ground launch of the glider until about 400 feet above ground level when the winch cable broke. The pilot stated that he lowered the nose and established a speed of at least 60 knots. He continued the upwind pattern until the glider was in a position to begin a right 180-degree turn in order to line up with the landing area. He stated: “I could feel in the controls that something was not right and the glider was not responding in the manner that I am accustomed. There were none of the signs of a stall and the glider did not behave like it has any time that I have practiced stalls. Before I could determine the cause or take any action, the nose abruptly dropped and we dove toward the intended runway.” The glider impacted the ground nose down and in a right bank. A postaccident inspection confirmed flight control continuity from each control surface to the aft cockpit control stick with two exceptions. The inspection noted two separation points in the flight control push-pull tubes at the aft fuselage and empennage. Both were consistent in location and appearance with overload failures due to impact forces. No anomalies consistent with a pre-impact failure or malfunction were observed. Metallurgical examination of the winch cable revealed features consistent with overstress fracture.
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
- Glider tow event during initial climb
- Off-field or emergency landing during maneuvering
- Aerodynamic stall/spin during maneuvering defining event
- Collision with terrain or object (not controlled flight into terrain) during uncontrolled descent
The NTSB's findings
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Airspeed › Not attained/maintained
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- factor Aircraft › Aircraft structures › Fuselage › Aerial tow equipment section › Failure other cases naming the airframe structure
Pilot
- Certificate: commercial pilot
- Ratings: single-engine land; rotorcraft: glider
- Flight time: 1,150 hours in all; 90 in this make and model; 28 in the last 90 days; 11 in the last 30 days; 926 as pilot in command
- Last flight review: May 1, 2009
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: rear
- Injury: serious injuries
The aircraft
- Airframe total time: 1,742 hours
- Last inspection: annual inspection, March 28, 2009
- Maximum gross weight: 1,323 lb
- Seats: 2
- Landing gear: fixed
The flight
- Departed from: 69G Gregory MI at 3:20 pm
- Destination: 69G Gregory MI
- Flight plan: none
- Runway 18, 2,471 ft by 100 ft
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: scat at 6,500 ft
- Temperature: 70°F (21°C), dew point 52°F (11°C)
- Altimeter: 30.04 inHg
- Observation at 3:16 pm from OZW, 12 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
7 documents, released by the NTSB on May 10, 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 | Pilot Statement | PDF, 1 page | View Download |
| 3 | Witness Statements | PDF, 7 pages | View Download |
| 4 | Accident Site Diagram | PDF, 2 pages | View Download |
| 5 | Conversation Record -- FAA Inspector | PDF, 1 page | View Download |
| 6 | Glider Maintenance Records -- Excerpts | PDF, 2 pages | View Download |
| 7 | Materials Laboratory 15 - Factual Report 09-097 | PDF, 3 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Other NTSB records under N103MS the same tail number, which may have belonged to a different aircraft at the time
Connections how this case links to the rest of the register
- N103MS on the register today · the tail number may have moved to another aircraft since
- Burkhart Grob G-103 71 registered today · the model family and its accident history
- Burkhart Grob 99 aircraft on the register
- Richmond Field · nearest airport
- Accidents and incidents in Michigan 2,107 since 1982 · 230 in the last ten years
- Michigan 7,236 aircraft registered
- Other NTSB records under N103MS 1 records · the number may have belonged to another aircraft at the time
The whole map of how records connect · these connections as data: /graph/accident/CEN09LA353.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.