CEN10CA371 · Brantly B-2B
Brantly B-2B · Accident: roll over during landing
From East Troy Municipal Airport (57C) to East Troy Municipal Airport (57C)
Event
- NTSB case
- CEN10CA371
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- General aviation
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Brantly B-2B
- Aircraft type
- Brantly B-2
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N9011R
- Operator
- Unknown
- Onboard fatalities
- Unknown
- Route
- From East Troy Municipal Airport (57C), East Troy, WITo East Troy Municipal Airport (57C), East Troy, WI
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 91: General Aviation
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Landing
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Roll over
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
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.
Probable cause
The pilot's failure to maintain control during landing.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record CEN10CA371
- Event ID
- 20100706X91624
- Case number
- CEN10CA371
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 68aab32383f24be47e993e0ee516a3b1eb95f91cc08db28a866f0f8b9810c812; retrieved 2026-09-15T14:37:11.926Z.