# NTSB SEA90FA158: Aerospatiale SA315B, N351RM, Cougar, WA, August 7, 1990

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Field investigation · Final report
- Date: August 7, 1990, 11:30 local (18:30 UTC)
- Place: Cougar, WA
- Coordinates: 46.19033, -122.129089 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=46.1903&lon=-122.1291&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious
- Status: Completed, report December 14, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 41121
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA90FA158
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41121/pdf
- Page: https://openairdocs.org/ntsb/SEA90FA158

## Probable cause

LOSS OF POWER DUE TO CONTAMINATION IN THE ENGINE SPEED GOVERNOR.

## Sequence of events

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

- Loss of engine power, hover
  - turboshaft engine,free turbine governor - contamination (cause)
- In flight collision with terrain/water, descent - uncontrolled

## Analysis

THE ACFT WAS HOVERING OVER TREES AT APPROX 200 FT. AGL, PICKING UP A LOAD OF LOGS DURING A LONG LINE HELI-LOGGING OPERATION, WHEN THE ENGINE LOST POWER. THE ACFT DESECENDED VERTICALLY AND IMPACTED THE TERRAIN. DISASSEMBLY AND EXAMINATION OF THE ENGINE SPEED GOVERNOR REVEALED PARTICLES OF SEALANT MATERIAL INSIDE THE GOVERNOR ASSY.

## Aircraft

- Registration: [N351RM](https://openairdocs.org/deregistered/N351RM-2013-05-30), registration cancelled 2013-05-30, S/N 2502, built 1977 (OpenAirDocs)
- Reported make and model: AEROSPATIALE SA315B
- Registry model: [Aerospatiale SA315B](https://openairdocs.org/model/aerospatiale-sa315b) (registry code 8680615) (OpenAirDocs)
- Registry engine: [Turbomeca ARTOUSTEIIIB](https://openairdocs.org/engine/turbomeca-artousteiiib) (registry code 60003, turbo-shaft) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2505
- Airframe hours: 11959
- Engines: TURBOMECA ARTOUSTE IIIB 853 horsepower turbo shaft
- Damage: Destroyed
- Flight: Other work use, Part 133
- Operator: Rocky Mountain Helicopters
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, July 27, 1990, 9 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; commercial; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 17,853 total, 7,698 in this make and model, 17,853 as pilot in command, 294 in the last 90 days, 78 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 310° at 5 knots
- Visibility: 40 statute miles
- Lowest ceiling: none
- Temperature: 73 °F, dew point 57 °F
- Altimeter: 30.00 inHg
- Observed at: PDX, 40 nm away

## 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 19900807030939A](https://openairdocs.org/incident/19900807030939A), Aug 7, 1990: Aerosp SA315B, Cougar, WA, Destroyed. Lost power while hovering with a sling load of logs. Dropped into trees. Found contamination in speed governor.

## Other investigations on N351RM (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 SEA93LA209](https://openairdocs.org/ntsb/SEA93LA209), Sep 24, 1993: Aerospatiale SA 315B (N351RM), Avery, ID, substantial damage. Probable cause: THE PILOT'S IMPROPER USE OF THE CYCLIC CONTROL.

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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