# NTSB DEN89FA175: Bell 206B, N1086C, Duchesne, UT, July 18, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: July 18, 1989, 13:15 local (19:15 UTC)
- Place: Duchesne, UT
- Coordinates: 40.09901, -110.490898 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.0990&lon=-110.4909&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report July 9, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 17598
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN89FA175
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/17598/pdf
- Page: https://openairdocs.org/ntsb/DEN89FA175

## Probable cause

THE PILOT FAILED TO MAINTAIN CLEARANCE FROM THE POWER LINE. CONTRIBUTING FACTORS WERE:  LACK OF MISSION TRAINING PROVIDED BY THE COMPANY/OPERATOR, THE PILOT'S LACK OF EXPERIENCE IN THIS TYPE OF OPERATION, HIS LACK OF FAMILIARITY WITH THE GEOGRAPHIC AREA, AND THE COMPANY/OPERATOR'S INADEQUATE SUBSTANTIATION PROCESS TO ASSURE THE EXPERIENCE LEVEL OF NEWLY HIRED PILOTS.

## Analysis

THE HELICOPTER WAS BEING OPERATED ON A SPECIALIZED POWER LINE PATROL TO CONDUCT 'KORONA MEASURING' FOR A 'LEAKAGE' CHECK OF THE TRANSMISSION LINE. THIS CHECK REQUIRED THAT THE HELICOPTER BE FLOWN AT A CONSTANT ALTITUDE & SPEED, & AT A DISTANCE OF 100' OR LESS FROM THE POWER LINE. WHILE PATROLLING EASTBOUND, THE MAIN ROTOR STRUCK THE NORTH STATIC LINE. SUBSEQUENTLY, THE MAIN ROTOR, SWASH PLATE, & TRANSMISSION/ROTOR MAST SEPARATED & THE HELICOPTER CRASHED. WHEN THE HELICOPTER DID NOT RETURN FROM THE PATROL, A SEARCH WAS ORGANIZED. THE WRECKAGE WAS FOUND THE NEXT DAY AT 1045 MDT. THE PLT & 1 PAX WERE DECEASED, BUT THE OTHER PAX APPEARED TO BE ALIVE; HOWEVER, HE DIED BEFORE MEDICAL ASSISTANCE ARRIVED. NO PREIMPACT PART FAILURE OR MALFUNCTION OF THE HELICOPTER WAS FOUND. AN INVESTIGATION REVEALED THIS WAS THE PILOT'S 1ST POWER LINE PATROL. ON HIS APPLICATION FOR RECENT EMPLOYMENT WITH THE COMPANY, HE INDICATED HE HAD OVER 1900 HRS OF FLT TIME; HOWEVER, ONLY 585 HRS OF FLT TIME COULD BE VERIFIED. HE DID NOT RCV MISSION TRAINING FOR THIS FLT.

## Sequence of events

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

- In flight collision with object, cruise
  - object - wire,transmission
  - object - wire,static
  - clearance - not maintained, pilot in command (cause)
  - inadequate training, company/operator management (contributing factor)
  - lack of total experience in type operation, pilot in command (contributing factor)
  - lack of familiarity with geographic area, pilot in command (contributing factor)
  - inadequate substantiation process, company/operator mgmt (contributing factor)

## Aircraft

- Registration: [N1086C](https://openairdocs.org/deregistered/N1086C-1998-08-10), registration cancelled 1998-08-10, S/N 2996 (OpenAirDocs)
- Reported make and model: BELL 206B
- Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2996
- Airframe hours: 6103
- Engines: ALLISON 250-C20B 317 horsepower turbo shaft
- Damage: Destroyed
- Flight: Other work use, Part 91
- Operator: Rocky Mountain Helicopter
- Registered owner: Michael Zicka Leasing Co
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, June 29, 1989, 84 hours before
- Departed: PVU, PROVO, UT
- Destination: PVU, PROVO, UT

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 34; commercial, flight instructor, private; airplane ratings: single-engine land; instrument ratings: airplane, helicopter; medical: class 2, valid medical--no waivers/lim.; toxicology performed; flight hours: 585 total, 57 in this make and model, 35 in the last 90 days, 35 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 270° at 3 knots
- Visibility: 60 statute miles
- Lowest ceiling: none
- Temperature: 90 °F

## 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 19890718023749A](https://openairdocs.org/incident/19890718023749A), Jul 18, 1989: Bell 206B, Duchesne, UT, Destroyed, 3 fatal. Struck a static powerline cable while flying close for a powerline test. Pilot had no prior powerline training.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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