Bell 206B accident near Shepherd, Montana, April 27, 2013
On April 27, 2013 at about 2:30 pm local time, a 1977 Bell 206B (helicopter), registered N150SP, was substantially damaged in an accident during maneuvering near Shepherd, Montana. It was a personal flight under general aviation rules (Part 91). 1 person was killed. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The pilot’s loss of control while maneuvering during low-altitude operations due to sudden neurological impairment or incapacitation and the helicopter’s subsequent collision with power lines.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- April 27, 2013 · about 2:30 pm local time
- Place
- Shepherd, Montana · map
- Type
- Accident
- Injuries
- 1 person was killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Bell 206B, built 1977 · all 206Bs on the register
- Registration
- N150SP · registry record · serial 2216
- Damage
- Substantial damage
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The pilot was maneuvering at low altitude during cattle herding operations. The helicopter collided with power lines and subsequently impacted terrain. Power lines were found wrapped around the main rotor mast about 25 times. Postaccident examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. A small amount of acute blood was found in the left ventricle of the pilot's brain, but no significant traumatic injuries were found; thus, it is likely the hemorrhage occurred during an acute premortem event. Given the autopsy findings and that the pilot knew the flying area well and would have likely known where the power lines were located, it is likely that he was impaired or incapacitated by an acute neurologic event in the seconds before impact with the power lines.
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
What happened, in order
- Controlled flight into terrain or object (CFIT) during maneuvering defining event
- Ground collision during post (impact)
- Fire/smoke (post-impact) during post (impact)
The NTSB's findings
- cause Personnel issues › Physical › Impairment/incapacitation › Neurological › Pilot
- cause Environmental issues › Physical environment › Object/animal/substance › Wire › Awareness of condition
Pilot
- Certificate: private
- Ratings: multi-engine land; single-engine land; instrument: airplane; rotorcraft: helicopter
- Flight time: 7,500 hours in all
- Medical certificate: Class 3 (with waivers/limitations)
- Seat: unk
- Injury: fatal
The aircraft
- Airframe total time: 10,417 hours
- Last inspection: 100-hour inspection, August 8, 2012
- Seats: 5
- Landing gear: fixed
- Engine: Allison 250-C20 (turboshaft); 7,815 hours total
- Fire on the ground
The flight
- Departed from: Worden MT at 1:15 pm
- Destination: Shepherd MT
- Flight plan: none
Weather at the time
- Light: daylight
- Wind: from 230° at 11 knots
- Visibility: 10 statute miles
- Sky: a few clouds at 12,000 ft
- Temperature: 55°F (13°C), dew point 28°F (-2°C)
- Altimeter: 30.06 inHg
- Observation at 1:53 pm from KBIL, 21 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 1 |
Other NTSB records under N150SP the same tail number, which may have belonged to a different aircraft at the time
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number WPR13FA208.