Aircraft Accident/Incident Report

Jelm, Wyoming 89003
Saturday, September 27, 2008 13:00 MDT

NTSB Narrative Summary Released at Completion of Accident

The pilot reported that he was flying over his ranch property at about 50 knots looking for stray cattle when "...a strong tailwind or twister caused the ship to vibrate very fast and violent, and dove to the right." The pilot stated that several people on the ground observed the helicopter spin 5 to 6 times before impacting the uneven and sloping ground and rolling over. The pilot further stated, "I couldn't get response from the tail rotor, collective, or cyclic." The ranch foreman saw the helicopter making a "big circle," followed by 3 or 4 "tight circles" in a clockwise direction before impacting terrain. A post crash examination of the helicopter by a Federal Aviation Administration (FAA) aviation safety inspector revealed no apparent malfunctions. The pilot reported no preimpact anomalies with the helicopter. The Rotorcraft Flying Handbook states that a loss of tail rotor effectiveness (LTE) is the occurrence of an uncommanded yaw rate that does not subside on its own accord, which can result in the loss of helicopter control. The recovery technique for LTE is full left pedal while simultaneously moving cyclic control forward to increase airspeed. If altitude permits, reduce power. FAA Advisory Circular 90-95 states, "Any maneuver which requires the pilot to operate in a high-power, low-airspeed environment with a left crosswind or tailwind creates an environment where unanticipated right yaw may occur."

NTSB Probable Cause Narrative

The pilot's encounter with a loss of tail rotor effectiveness event and his failure to maintain directional control while maneuvering. Contributing to the accident were the tailwind condition and the sloping, uneven terrain.

Event Information

Type of Event Accident
Event Date 9/27/2008
Event Day of the Week Saturday
Time of Event 1300
Event Time Zone Mountain Daylight Time
Event City Jelm
Event State WYOMING
Event Country --
Zipcode of the event site 89003
Event Date Year 2008
Event Date Month 9
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 410429N
Event Location Longitude 1055500W
Event Location Airport --
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 --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1353 Mountain Daylight Time
Direction of event from weather observation facility (degrees) 210
Weather Observation Facility ID LAR
Elevation of weather observation facility 7284
Distance of event from weather observation facility (units?) 20
Time Zone of the weather observation MDT
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 11000
Sky/Lowest/Cloud Conditions Scattered
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) 23
Dew Point at event time (in degress fahrenheit) -3
Wind Direction (degrees magnetic) --
Variable Wind Indicator Variable
Wind Speed (knots) 6
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.31
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury Serious
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None --
Injury Total Serious 1
Injury Total All 1
Investigating Agency NTSB
NTSB Docket Number (internal use) 24969
NTSB Notification Source Regional 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 Jan 23 2009 7:43PM
User who most recently changed record stam
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N59611
NTSB Number SEA08LA213
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name BELL
Aircraft Model 206B
Aircraft Series Identifier --
Aircraft Serial Number 1515
Certified Max Gross Weight 3200
Aircraft Category Helicopter
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats 1
Cabin Crew Seats --
Passenger Seats 4
Total number of seats on the aircraft 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection Annual
Date of Last Inspection Jul 20 2006 12:00AM
Airframe hours since last inspection 12
Airframe Hours 2519
ELT Installed Yes
ELT Activated Yes
ELT Aided Location of Event Site No
ELT Type Unknown
Aircraft Owner Name James E Simon Co.
Aircraft Owner Street Address --
Aircraft Owner City Cheyenne
Aircraft Owner State WY
Aircraft Owner Country USA
Aircraft Owner Zipcode 82003
Operator is an individual? No
Operator Name James E Simon
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address --
Operator City Cheyenne
Operator State WY
Operator Country USA
Operator Zip code 82003
Operator Code --
Owner has at least one certificate None
Other Operator of large aircraft? No
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 Laramie
Departure State WY
Departure Country USA
Departure Time 1230
Departure Time Zone MDT
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code --
Destination City Laramie
Destination State WY
Destination Country USA
Specific Phase of Flight --
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 23 2009 7:43PM
User who most recently changed record stam
Since inspection or accident Time of Accident
Event Location Runway Number and Location N/A
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --