# NTSB DEN86LA151: Bell 206B, N59495, Portal, ND, June 4, 1986

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: June 4, 1986, 16:15 local (21:15 UTC)
- Place: Portal, ND
- Coordinates: 48.959632, -102.620155 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=48.9596&lon=-102.6202&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16972
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN86LA151
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16972/pdf
- Page: https://openairdocs.org/ntsb/DEN86LA151

## Sequence of events

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

- In flight collision with object, maneuvering - aerial application
  - object - wire,transmission (contributing factor)
  - visual lookout - not maintained, pilot in command (cause)
  - rotorcraft flight control,collective control - disabled
- In flight collision with terrain/water, landing
- Roll over, landing

## Analysis

THE PLT REPORTED THAT THE ACFT HIT WIRES AT THE END OF A SWATH RUN. THE PITCH CHANGE LINK BROKE WHEN THE MAIN ROTOR CONTACTED THE WIRES AND THE PLT ATTEMPTED TO LAND. AFTER TOUCHDOWN, THE HELICOPTER ROLLED ONTO ITS SIDE.

## Aircraft

- Registration: [N59495](https://openairdocs.org/aircraft/N59495), registered now, S/N 1373, built 1954 (OpenAirDocs)
- Reported make and model: BELL 206B
- Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs)
- Registry engine: [Allison 250 SER 400HP](https://openairdocs.org/engine/allison-250-ser-400hp) (registry code 03013, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1373
- Airframe hours: 2000
- Engines: ALLISON 250-C20B 400 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Knutson Flying Service, Inc.
- Airworthiness certificate: Standard, Utility
- Last inspection: Annual, April 8, 1986, 19 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 64; commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 41,000 total, 2,000 in this make and model, 40,670 as pilot in command, 75 in the last 90 days, 14 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 25 statute miles
- Lowest ceiling: none
- Temperature: 81 °F
- Altimeter: 29.00 inHg

## 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 19860604021419A](https://openairdocs.org/incident/19860604021419A), Jun 4, 1986: Bell 206B, Portal, ND, Substantial damage. The helicopter struck wires during a spraying operation. Aircraft rolled over on landing.

## Other investigations on N59495 (1)

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.

- [NTSB SEA76FTA09](https://openairdocs.org/ntsb/SEA76FTA09), Dec 14, 1975: Bell 206B (N59495), Miles City, MT, substantial damage

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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