Brantly B-2B accident near East Troy, Wisconsin, July 4, 2010
On July 4, 2010 at about 10:45 pm local time, a Brantly B-2B (helicopter), registered N9011R, was substantially damaged in an accident during landing near East Troy, Wisconsin (East Troy Municipal Airport). It was a flight test under general aviation rules (Part 91). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot's failure to maintain control during landing.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 4, 2010 · about 10:45 pm local time
- Place
- East Troy, Wisconsin · East Troy Municipal Airport · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Brantly B-2B · all B-2Bs on the register
- Registration
- N9011R · registry record · serial 2013
- Damage
- Substantial damage
- Flight
- Flight test · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The helicopter pilot performed a straight-in autorotation to runway 18 for a rotor rpm check. The engine rpm began to rapidly increase and the pilot rolled the throttle completely off and lowered collective. He reported that the left skid was coming off the ground and he applied full left cyclic and full down collective. The aircraft teetered and continued to roll right. The pilot stated that the helicopter had an articulated landing gear system. He said that the struts travel approximately seven to eight inches and “if only one side retracts it causes a ‘rolling moment’.” About 22 minutes before the accident, the recorded winds about seven nautical miles and 155 degrees from the accident site were 200 degrees at 14 knots with gusts to 32 knots. An examination of the accident helicopter’s controls and landing gear revealed no preexisting anomalies.
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
- Roll over during landing defining event
The NTSB's findings
- cause Personnel issues › Task performance › Use of equip/info › Aircraft control › Pilot
- Environmental issues › Conditions/weather/phenomena › Wind › Gusts › Not specified
- Environmental issues › Conditions/weather/phenomena › Wind › Crosswind › Not specified
Pilot
- Certificate: flight instructor, commercial pilot
- Ratings: instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 2,603 hours in all; 70 in this make and model; 200 in the last 90 days; 85 in the last 30 days; 2,575 as pilot in command; 623 on instruments
- Last flight review: June 10, 2010
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 602 hours
- Last inspection: annual inspection, July 4, 2010
- Maximum gross weight: 1,670 lb
- Seats: 2
- Landing gear: fixed
- Engine: Lycoming IVO-360 (piston); 0 hours total
The flight
- Departed from: 57C East Troy WI at 10:35 pm
- Destination: 57C East Troy WI
- Flight plan: none
- Runway 18
Weather at the time
- Light: daylight
- Wind: from 200° at 14 knots, gusting 32
- Visibility: 10 statute miles
- Sky: broken clouds at 9,000 ft; scat at 3,500 ft
- Temperature: 79°F (26°C), dew point 70°F (21°C)
- Altimeter: 29.88 inHg
- Observation at 10:34 pm from BUU, 7 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CEN10CA371.