Aerospatiale AS-341G accident near Alma, Oregon, February 17, 1984
On February 17, 1984 at about 4:10 pm local time, a Aerospatiale AS-341G (helicopter), registered N633B, was substantially damaged in an accident near Alma, Oregon (None airport). It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 2 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The NTSB has not yet published a probable cause for this accident. Investigations usually take one to two years; this page updates when the final report is released.
Source: NTSB aviation accident database, copy made November 2, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- February 17, 1984 · about 4:10 pm local time · cases in 1984
- Place
- Alma, Oregon · None · map
- Type
- Accident
- Injuries
- No one was hurt; 2 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale AS-341G
- Registration
- N633B · registry record · serial 1040
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
THE PLT STATED HE LOST PARTIAL POWER ON A X-COUNTRY FLT, DURING CRUISE, AND INITIATED AN AUTOROTATION. AT ABOUT 200 TO 300 FT AGL HE REDUCED THE THROTTLE TO IDLE. DURING FLARE THE ROTOR RPM DECAYED AND THE ACFT LANDED HARD AND ROLLED OVER.THE PILOT STATED THAT THE FUEL FILTER HAD BACKED OFF.
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: single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 5,116 hours in all; 4,848 in this make and model; 68 in the last 90 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 4,905 hours
- Last inspection: 100-hour inspection, October 3, 1983; 22 hours since
- Maximum gross weight: 3,970 lb
- Seats: 5
- Landing gear: retractable
- Engine: Astazou 111A (turboshaft); 0 hours total
The flight
- Departed from: EUG Eugene OR at 3:50 pm
- Destination: OTH North Bend OR
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 230° at 5 knots
- Visibility: 5 statute miles
- Temperature: 30°F (-1°C), dew point 28°F (-2°C)
- Altimeter: 30.00 inHg
- Observation at 4:47 pm from EUG, 25 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 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.
Connections how this case links to the rest of the register
- N633B on the register today · the tail number may have moved to another aircraft since
- Aerospatiale 178 aircraft on the register
- Engine: Astazou 111A · as the NTSB recorded it
- Mahlon Sweet Field · departed from
- Southwest Oregon Regional · bound for
- Accidents and incidents in Oregon 1,864 since 1982 · 279 in the last ten years
- Oregon 7,008 aircraft registered
The whole map of how records connect · these connections as data: /graph/accident/SEA84LA054.json.
The bigger picture in Aviation Analytics: accidents over time since 1982, by model, by phase of flight and conditions, by place and on the map.
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 does not name anyone involved, its policy at this time. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.