# NTSB DEN85FA007: Bell 206B, N3912T, Cheyenne, WY, October 9, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: October 9, 1984, 14:15 local (20:15 UTC)
- Place: Cheyenne, WY
- Location: 41.1400° N, 104.8202° W: Placed by OpenAirDocs: center of Cheyenne, WY, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.1400&lon=-104.8202&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 16504
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN85FA007
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/16504/pdf
- Page: https://openairdocs.org/ntsb/DEN85FA007

## Sequence of events

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

- In flight collision with object, takeoff
  - rotor system,tail rotor blade - loss,partial (contributing factor)
  - judgment - inaccurate, pilot in command (cause)
  - rotorcraft flight control,tail rotor pedal - vibration (contributing factor)
  - proper descent rate - not attained, pilot in command (cause)
  - object - wire,transmission
- Roll over, landing - flare/touchdown
  - terrain condition - open field
  - light condition - daylight

## Analysis

THE HELICOPTER'S TAIL ROTOR SECTION CONTACTED A PWR LINE DURING AN ATTEMPTED TAKEOFF.  A SECTION OF TAIL ROTOR BLADE TIPWAS FOUND BENEATH THE PWR LINES.  THE PILOT REPORTED A VIBRATION IN THE TAIL ROTOR CONTROL PEDALS.  HE ATTEMPTED A LANDING INTO AN OPEN FIELD.  DURING THE TOUCHDOWN THE HELICOPTER SPUN TO THE RIGHT AND ROLLED COMING TO REST ON ITS LEFT SIDE.

## Aircraft

- Registration: N3912T (not matched to a registry record)
- Reported make and model: BELL 206B
- Category: Helicopter
- Serial number: 3273
- Airframe hours: 21723
- Engines: ALLISON 250-C20B 317 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Business, Part 91
- Registered owner: Associates Helicopter Services
- Airworthiness certificate: Standard, Normal

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: helicopter; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 5,800 total, 1,152 in this make and model, 87 in the last 90 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 5 knots
- Visibility: 50 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point -0 °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 19841009054769A](https://openairdocs.org/incident/19841009054769A), Oct 9, 1984: Bell 206B, Cheyenne, WY, Substantial damage. Tail rotor struck power line on takeoff. Nose turned during power on landing, helicopter rolled on to its side.

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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