# NTSB LAX90LA283: Bell 206B II, N2917W, San Francisco, CA, August 14, 1990

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: August 13, 1990, 18:36 local (Aug 14, 1990, 01:36 UTC)
- Place: San Francisco, CA
- Coordinates: 37.79076, -122.459129 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=37.7908&lon=-122.4591&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 2 minor, 1 uninjured
- Status: Completed, report November 23, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26889
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90LA283
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26889/pdf
- Page: https://openairdocs.org/ntsb/LAX90LA283

## Probable cause

THE PILOT'S FAILURE TO MAINTAIN DIRECTIONAL CONTROL OF THE HELICOPTER. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S DECISION TO OPERATE THE HELICOPTER IN A FLIGHT REGIME CONDUCIVE TO UNANTICIPATED RIGHT YAW.

## 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 - tailwind (contributing factor)
  - in-flight planning/decision - inadequate, pilot in command (contributing factor)
  - airspeed - not maintained, pilot in command (cause)
  - directional control - not maintained, pilot in command (cause)
  - remedial action - inadequate, pilot in command (contributing factor)
- Forced landing, descent - emergency
- In flight collision with terrain/water, descent - emergency
  - terrain condition - water,rough

## Analysis

PILOT WAS MANEUVERING HIS HELIOCPTER IN A CLIMBING RIGHT TURN AROUND A SAILBOAT TO PROVIDE AN AERIAL PLATFORM FOR A MOVIE FILM CREW. ABOUT 100 FEET ABOVE THE WATER AND A FEW FEET FROM THE SAILBOAT MAST, THE HELICOPTER BEGAN TO SPIN TO THE RIGHT. THE PILOT STATED THAT THE HELICOPTER WAS DOWNWIND FROM THE RELATIVE WIND DIRECTION. THE PILOT REDUCED COLLECTIVE PITCH AND THE SPIN STOPPED. DUE TO THE COLLECTIVE REDUCTION, THE PILOT WAS UNABLE TO REGAIN CONTROL OF THE HELICOPTER BEFORE IT STRUCK THE OCEAN SURFACE AND SANK.

## Aircraft

- Registration: [N2917W](https://openairdocs.org/deregistered/N2917W-2012-09-24), registration cancelled 2012-09-24, S/N 806, built 1972 (OpenAirDocs)
- Reported make and model: BELL 206B II
- Registry model: [Bell 206B](https://openairdocs.org/model/bell-206b) (registry code 1181511) (OpenAirDocs)
- Registry engine: [Allison 250 SER 317HP](https://openairdocs.org/engine/allison-250-ser-317hp) (registry code 03011, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 806
- Airframe hours: 7955
- Engines: ALLISON 250-C-20 420 horsepower turbo shaft
- Damage: Destroyed
- Flight: Other work use, Part 91
- Operator: Astro Copters Ltd.
- Registered owner: Dwayne V. Vandagriff
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, August 9, 1990, 7 hours before
- Departed: SAN RAFAEL, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 9,130 total, 3,300 in this make and model, 8,997 as pilot in command, 100 in the last 90 days, 55 in the last 30 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 270° at 18 knots
- Visibility: 50 statute miles
- Temperature: 64 °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 19900813033449A](https://openairdocs.org/incident/19900813033449A), Aug 13, 1990: Bell 206B, San Franciso, CA, Destroyed. Allowed yaw rate to commence in tail rotor vortex ring state without prompt rudder use. Spun into water and sank.

## Other investigations on N2917W (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 LAX85LA045](https://openairdocs.org/ntsb/LAX85LA045), Nov 10, 1984: Bell 206B (N2917W), Inverness, CA, 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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