N/A Airport
Aircraft Accident/Incident Report

Shepherd, Montana 59079
Saturday, April 27, 2013 8:30 MDT

NTSB Narrative Summary Released at Completion of Accident

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.

NTSB Probable Cause Narrative

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.

Event Information

Type of Event Accident
Event Date 4/27/2013
Event Day of the Week Saturday
Time of Event 830
Event Time Zone Mountain Daylight Time
Event City Shepherd
Event State MONTANA
Event Country --
Zipcode of the event site 59079
Event Date Year 2013
Event Date Month 4
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 460519N
Event Location Longitude 1081447W
Event Location Airport N/A
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 21
Degrees magnetic from airport 36
Airport Elevation 3652
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1353 Coordinated Universal Time? Same as GMT
Direction of event from weather observation facility (degrees) 216
Weather Observation Facility ID KBIL
Elevation of weather observation facility 3570
Distance of event from weather observation facility (units?) 21
Time Zone of the weather observation UTC
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 12000
Sky/Lowest/Cloud Conditions Few
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 13
Dew Point at event time (in degress fahrenheit) -2
Wind Direction (degrees magnetic) 230
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 11
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.07
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report KBIL 271353Z 23011KT 10SM FEW120 13/M02 A3007 RMK
Event Highest Injury Fatal
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal 1
Injury Total Minor --
Injury Total None --
Injury Total Serious --
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 32674
NTSB Notification Source FAA NWM Operations Center
NTSB Notification Date --
NTSB Notification Time --
Fiche Number and/or location -used to find docket information --
Date of most recent change to record Apr 16 2014 11:02AM
User who most recently changed record swia
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N150SP
NTSB Number WPR13FA208
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire Ground
Aircraft Explosion Unknown
Aircraft Manufacturer's Full Name BELL
Aircraft Model 206B
Aircraft Series Identifier --
Aircraft Serial Number 2216
Certified Max Gross Weight --
Aircraft Category Helicopter
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats 2
Passenger Seats --
Total number of seats on the aircraft 5
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Aug 8 2012 12:00AM
Airframe hours since last inspection --
Airframe Hours 10417
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type Unknown
Aircraft Owner Name TONGUE CANYON AVIATION LLC
Aircraft Owner Street Address --
Aircraft Owner City WORDEN
Aircraft Owner State MT
Aircraft Owner Country USA
Aircraft Owner Zipcode 59088-9608
Operator is an individual? Yes
Operator Name Dan Sandall Scott
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City WORDEN
Operator State MT
Operator Country USA
Operator Zip code 59088-9608
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Personal
Second Pilot on Board No
Departure Point Same as Event No
Departure Airport Code --
Departure City Worden
Departure State MT
Departure Country USA
Departure Time 715
Departure Time Zone MDT
Destination Same as Local Flt crash at destination city
Destination Airport Code --
Destination City Shepherd
Destination State MT
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record May 14 2014 11:44AM
User who most recently changed record stam
Since inspection or accident Last Inspection
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --