# NTSB SEA91FA223: Aerospatiale 350 B1, N64SF, Walton, OR, August 29, 1991

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: August 28, 1991, 23:59 local (Aug 29, 1991, 06:59 UTC)
- Place: Walton, OR
- Coordinates: 44.019691, -123.620132 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.0197&lon=-123.6201&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 3 fatal
- Status: Completed, report March 31, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 41337
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91FA223
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41337/pdf
- Page: https://openairdocs.org/ntsb/SEA91FA223

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN CLEARANCE FROM TERRAIN.

## Sequence of events

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

- In flight collision with terrain/water, maneuvering
  - terrain condition - mountainous/hilly
  - clearance - not maintained, pilot in command (cause)
  - weather condition - drizzle/mist
  - light condition - dark night
  - in-flight planning/decision - inadequate, pilot in command (contributing factor)

## Analysis

WHILE MANEUVERING IN REMOTE MOUNTAINOUS TERRAIN, ON A DARK NIGHT, WITH LIGHT DRIZZLE AND PATCHY CLOUDS, THE HELICOPTER COLLIDED WITH A MOUNTAIN. THE WRECKAGE SCATTERED ON A HEADING OPPOSITE THE FLIGHTS DESTINATION. THE HELICOPTER WAS DESTROYED BY A POST CRSH FIRE AND THERE WERE NO NOTED MECHANICAL FAILURES OR MALFUNCTIONS.

## Aircraft

- Registration: [N64SF](https://openairdocs.org/deregistered/N64SF-1991-10-22), registration cancelled 1991-10-22, S/N 2148 (OpenAirDocs)
- Reported make and model: AEROSPATIALE 350 B1
- Registry model: [Aerospatiale AS350B1 ECUREUIL](https://openairdocs.org/model/aerospatiale-as350b1-ecureuil) (registry code 8680811) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2148
- Engines: TURBOMECA ARRIEL 1 684 horsepower turbo shaft
- Damage: Destroyed
- Fire: On-Ground
- Flight: Part 135
- Operator: Bohemia Inc.
- Registered owner: Bohemia Inc.
- Last inspection: 100 hour, July 30, 1991
- Destination: EUG, EUGENE, OR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 55; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--w/ waivers/lim; seat: right; toxicology performed; flight hours: 10,277 total, 1,575 in this make and model, 129 in the last 90 days, 50 in the last 30 days

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: calm
- Visibility: 12 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 19910828037879A](https://openairdocs.org/incident/19910828037879A), Aug 28, 1991: Snias AS350B1, Walton, OR, Destroyed, 3 fatal. Flew into trees on a mountainside at night while transporting accident victim to a hospital. Mist clouds in area.

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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