Bell 206B II accident near Sheep Mountain, Montana, July 16, 2007
On July 16, 2007 at about 2:30 pm local time, a Bell 206B II (helicopter), registered N164JS, was substantially damaged in an accident near Sheep Mountain, Montana (Off Airport). It was an external-load flight under external-load helicopter rules (Part 133). 1 person had minor injuries. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The external load net, attached directly to the cargo hook without the use of a long line, oscillated and made contact with the tail rotor system while maneuvering.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 16, 2007 · about 2:30 pm local time
- Place
- Sheep Mountain, Montana · Off Airport · map
- Type
- Accident
- Injuries
- 1 person had minor injuries.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206B II · all 206B IIs on the register
- Registration
- N164JS · no longer on the register · serial 955
- Damage
- Substantial damage
- Flight
- External-load flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
The helicopter was transporting supplies with a cargo net from one mountain site to another. The sling loads consisted of steel angle iron, which was bagged and secured with velcro, and then placed into the cargo net. After delivering the fourth load, the pilot lifted off with only an empty bag inside the net. The Bell 206B rotorcraft flight manual, in the supplement for external loading, states, "Control movements should be made smoothly and kept to a minimum to prevent oscillation of sling load." According to a witness, as the helicopter departed, the net "floated very close to the propeller [tail rotor], then floated back down." The net, which was attached directly to the helicopter cargo hook without the use of a long line, swung back up again and impacted the tail rotor, cutting the cargo net and releasing the bag. The pilot heard noise and "thumping" sounds, accompanied by vibrations and yawing, and realized that he had a tail rotor strike. The pilot entered an autorotation at "25 miles per hour and 200 feet" above a timbered slope. The pilot selected a small, sloped, clearing as a landing zone, and upon touchdown, the helicopter rolled over, coming to rest on it's right side.
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: flight instructor, commercial pilot
- Ratings: multi-engine sea; single-engine land; instructor: helicopter; instrument: helicopter; rotorcraft: helicopter
- Flight time: 12,860 hours in all; 3,000 in this make and model; 31 in the last 90 days; 8 in the last 30 days; 12,000 as pilot in command
- Last flight review: May 1, 2007
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: minor injuries
The aircraft
- Airframe total time: 5,043 hours
- Last inspection: type not recorded, June 1, 2007
- Maximum gross weight: 3,350 lb
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250C20 (turboshaft); 0 hours total
- Fire on the ground
The flight
- Departed from: Mtn Drop Site MT at 2:20 pm
- Destination: Mtn Drop Site MT
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 30 statute miles
- Sky: clear
- Temperature: 64°F (18°C), dew point 0°F (-18°C)
- Altimeter: 29.92 inHg
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.