Aerospatiale 316B accident near Naturita, Colorado, July 26, 1984
On July 26, 1984 at about 1:45 pm local time, a Aerospatiale 316B (helicopter), registered N4246, was substantially damaged in an accident near Naturita, Colorado. It was an other work-use flight under external-load helicopter rules (Part 133). No one was hurt; 1 person was 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 October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 26, 1984 · about 1:45 pm local time
- Place
- Naturita, Colorado · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Aerospatiale 316B
- Registration
- N4246 · registry record · serial 1884
- Damage
- Substantial damage
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
ONE OF THE AXIAL COMPRESSOR BLADES SEPARATED RESULTING IN INTERNAL ENGINE DAMAGE AND LOSS OF ENGINE POWER. EXAMINATION OF THE BLADES SHOWED EVIDENCE OF CORROSION BEYOND ACCEPTABLE LIMITS. THE ENGINE WAS NOT EQUIPPED WITH AN AIR FILTER OR PARTICLE SEPARATOR. HELICOPTER DAMAGE WAS SUSTAINED DURING GROUND CONTACT.
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; rotorcraft: helicopter
- Flight time: 8,500 hours in all; 150 in this make and model; 15 in the last 90 days
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: rgt
The aircraft
- Airframe total time: 6,253 hours
- Last inspection: 100-hour inspection, July 25, 1984; 3 hours since
- Maximum gross weight: 4,630 lb
- Seats: 7
- Landing gear: fixed
- Engine: Turbomeca ARTOUSTE IIB (turboshaft); 0 hours total
- Operator: Alpine Helicopter Services INC
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Visibility: 60 statute miles
- Sky: clear
- Temperature: 70°F (21°C), dew point 0°F (-18°C)
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.
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.