# NTSB CHI08CA021: Bell 206B-III, N51698, Medora, ND, October 18, 2007

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Data collection · Final report
- Date: October 18, 2007, 11:05 local (17:05 UTC)
- Place: Medora, ND
- Coordinates: 46.9325, -103.31805
- Nearby events: https://openairdocs.org/map.md?lat=46.9325&lon=-103.3180&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor
- Status: Completed, report December 20, 2007
- Report: Approved by Office Director
- Parties: FAR FSDO
- NTSB case key (mKey): 66984
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI08CA021
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/66984/pdf
- Page: https://openairdocs.org/ntsb/CHI08CA021

## Probable cause

The pilot failed to maintain clearance from the fence while maneuvering at a low altitude, which resuled in the helicopter rolling over and impacting the terrain.  A factor associated with the accident was the fence.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- In flight collision with object, maneuvering
  - low altitude flight/maneuver - performed, pilot in command (contributing factor)
  - clearance - not maintained, pilot in command (cause)
  - object - fence (contributing factor)
- Loss of control - in flight, maneuvering
  - dynamic rollover - inadvertent, pilot in command (cause)
- In flight collision with terrain/water, descent - uncontrolled
  - terrain condition - ground

## Analysis

The pilot lost control of the helicopter and it impacted the terrain after a skid caught the top of a wire fence.  The helicopter was being used for a herding mission when the left skid caught the top wire of a ten foot high fence.  The helicopter began a dynamic roll to the left and impacted the ground. The pilot reported trying to counteract the roll by "reducing the power and adjusting the cyclic but was unsuccessful."

## Factual narrative

The helicopter impacted the terrain after a skid caught the top of a wire fence.  The helicopter was being used for a herding mission when the left skid caught the top wire of a ten foot high fence.  The helicopter began a dynamic roll to the left and impacted the ground. The pilot reported trying to counteract the roll by "reducing the power and adjusting the cyclic but was unsuccessful."  The main rotor blades were destroyed, the main rotor system separated from the mast, the main transmisison deck ripped from the fuselage and the tailboom separated from the fuselage.  The pilot and passenger received minor injuries.

## Aircraft

- Registration: [N51698](https://openairdocs.org/deregistered/N51698-2011-05-14), registration cancelled 2011-05-14, S/N 4010, built 1988 (OpenAirDocs)
- Reported make and model: Bell 206B-III
- Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs)
- Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs)
- Category: Helicopter
- Serial number: 4010
- Airframe hours: 11967
- Engines: Rolls-Royce 250-C20R-2 turbo shaft
- Damage: Substantial damage
- Flight: Public aircraft - federal, Part 91
- Registered owner: El Aero Services
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, September 1, 2007
- Departed: Medora, ND
- Destination: Medora, ND

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 69; injuries: minor; flight instructor, commercial; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review July 1, 2007; seat: right; flight hours: 35,000 total, 21,000 in this make and model, 300 in the last 90 days, 100 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 338° at 10 knots, gusting 21
- Visibility: 7 statute miles
- Lowest ceiling: 2,900 ft overcast
- Temperature: 45 °F, dew point 43 °F
- Altimeter: 29.55 inHg
- Observed at: 4 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 20071018824639A](https://openairdocs.org/incident/20071018824639A), Oct 18, 2007: Bell 206B, Dickinson, ND, Destroyed. (-23) On October 19, 2007, at 11:10 am local time a Bell 206, N51698, operated by a commercial pilot was destroyed while herding horses 20 miles west of…

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.

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