Bell 204B accident near Libby, Montana, May 27, 1994
On May 27, 1994 at about 7:00 pm local time, a Bell 204B (helicopter), registered N911SW, was substantially damaged in an accident near Libby, Montana. 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
THE FATIGUE FRACTURE OF THE 42 DEGREE GEAR BOX INPUT PINION. FACTORS INCLUDE UNSUITABLE, MOUNTAINOUS/HILLY TERRAIN.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 27, 1994 · about 7:00 pm local time
- Place
- Libby, Montana · map
- Type
- Accident
- Injuries
- 1 person was seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 204B · all 204Bs on the register
- Registration
- N911SW · no longer on the register · serial 2025
- Damage
- Substantial damage
- Flight
- Other work-use flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
JUST AFTER LIFTING A SINGLE-LOG EXTERNAL LOAD, THE HELICOPTER EXPERIENCED A FAILURE OF THE 42 DEGREE GEAR BOX INPUT PINION GEAR. THE PILOT RELEASED THE LOAD, AND BEGAN AN EMERGENCY DESCENT IN ORDER TO ATTEMPT A FORCED LANDING IN THE MOUNTAINOUS/HILLY TERRAIN. WHILE ATTEMPTING TO INITIATE THE LANDING FLARE, THE AIRCRAFT IMPACTED THE TERRAIN.
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, private
- Ratings: single-engine land; instrument: helicopter; rotorcraft: helicopter
- Flight time: 8,780 hours in all; 2,150 in this make and model; 150 in the last 90 days; 58 in the last 30 days; 8,780 as pilot in command
- Medical certificate: Class 2 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 12,884 hours
- Last inspection: 100-hour inspection, May 25, 1994; 12 hours since
- Maximum gross weight: 9,500 lb
- Seats: 11
- Landing gear: fixed
- Engine: Lycoming T53-13B (turboshaft); 0 hours total
The flight
- Flight plan: none
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 310° at 5 knots
- Visibility: 50 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.