# NTSB SEA89LA148: Bell 206B, N9916K, Boulder City, NV, August 7, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: August 6, 1989, 18:45 local (Aug 7, 1989, 01:45 UTC)
- Place: Boulder City, NV
- Coordinates: 35.989463, -114.810272 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.9895&lon=-114.8103&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 5 uninjured
- Status: Completed, report August 2, 1990
- Report: Approved by Office Director
- NTSB case key (mKey): 41061
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA89LA148
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41061/pdf
- Page: https://openairdocs.org/ntsb/SEA89LA148

## Probable cause

PILOT DISPLAYED POOR INFLIGHT PLANNING WHILE MANEUVERING. THE PILOT DID NOT IDENTIFY THE WIND CONDITIONS RESULTING IN A LOSS OF DIRECTIONAL CONTROL. THE PILOT'S CORRECTIVE ACTION WAS INADEQUATE AND AS RESULT, THE HELICOPTER COLLIDED WITH THE TERRAIN.

## Sequence of events

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

- Loss of control - in flight, maneuvering
  - weather condition - high wind (contributing factor)
  - directional control - not maintained, pilot in command (cause)
  - remedial action - inadequate, pilot in command (contributing factor)
  - compensation for wind conditions - inadequate, pilot in command (contributing factor)
  - in-flight planning/decision - poor, pilot in command (cause)
- Hard landing, landing - flare/touchdown
  - terrain condition - ground (contributing factor)
  - autorotation - performed, pilot in command

## Analysis

DURING A SIGHTSEEING FLIGHT, THE PILOT DESCENDED THE HELICOPTER TO A LOW ALTITUDE AND DECREASED AIRSPEED. THE PILOT THEN REPORTED THAT THE HELICOPTER LOST TAIL ROTOR EFFECTIVENESS AND BEGAN TO SPIN. THE PILOT WAS UNABLE TO REGAIN CONTROL OF THE HELICOPTER PRIOR TO IT TOUCHING DOWN HARD. THE PILOT REPORTED THAT THERE WERE NO MECHANICAL FAILURES OR MALFUNCTIONS WITH THE HELICOPTER AT THE TIME OF THE ACCIDENT.

## Aircraft

- Registration: N9916K (not matched to a registry record)
- Reported make and model: BELL 206B
- Category: Helicopter
- Serial number: 1939
- Engines: ALLISON 250-C20B 425 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Part 135
- Registered owner: Helicopter Services
- Departed: LAS, LAS VEGAS, NV
- Destination: LAS, LAS VEGAS, NV
- Flight plan: Company VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; flight hours: 2,200 total, 300 in this make and model, 1,745 as pilot in command, 104 in the last 90 days, 48 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 170° at 25 knots
- Visibility: 7 statute miles
- Temperature: -0 °F, dew point -0 °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 19890806031599A](https://openairdocs.org/incident/19890806031599A), Aug 6, 1989: Bell 206B, Boulder City, NV, Substantial damage. Slowed to 30 knots at 20 ft AGL for sightseeing. Strong tailwind caused loss of tail rotor effect. Put it down hard

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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