Aerospatiale SA315B accident near Cougar, Washington, August 7, 1990
On August 7, 1990 at about 6:30 pm local time, a Aerospatiale SA315B (helicopter), registered N351RM, was destroyed in an accident near Cougar, Washington. It was an other work-use flight under external-load helicopter rules (Part 133). 1 person was seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
LOSS OF POWER DUE TO CONTAMINATION IN THE ENGINE SPEED GOVERNOR.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 7, 1990 · about 6:30 pm local time
- Place
- Cougar, Washington · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale SA315B · all SA315Bs on the register
- Registration
- N351RM · no longer on the register · serial 2505
- Damage
- Destroyed
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
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.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
Pilot
- Certificate: commercial pilot
- Ratings: rotorcraft: helicopter
- Flight time: 17,853 hours in all; 7,698 in this make and model; 294 in the last 90 days; 78 in the last 30 days; 17,853 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 11,959 hours
- Last inspection: approved inspection programme, July 27, 1990; 9 hours since
- Maximum gross weight: 5,070 lb
- Seats: 5
- Landing gear: fixed
- Engine: Turbomeca ARTOUSTE IIIB (turboshaft); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 310° at 5 knots
- Visibility: 40 statute miles
- Sky: scat at 20,000 ft
- Temperature: 73°F (23°C), dew point 57°F (14°C)
- Altimeter: 30.00 inHg
- Observation at 5:50 pm from PDX, 40 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N351RM the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.