Individually Owned: 151,845
Corporate Owned: 143,699
Three Forks Airport
Aircraft Accident/Incident Report
Three Forks, Montana 59752
Saturday, January 15, 2011 13:00 MST
NTSB Narrative Summary Released at Completion of Accident
The pilot practiced several maneuvers and then entered a straight-in practice autorotation. He pointed the helicopter into the wind at 800 feet above ground level near midfield and above the runway. He reduced the throttle to flight idle and lowered the collective while gently flaring the nose of the helicopter to set up the appropriate main rotor rpm and airspeed. He reported that he monitored those parameters carefully during the descent and noted that they remained well within the normal range. At the bottom of the descent, the pilot flared a little high to allow a margin of safety for tail boom clearance as he was planning a power recovery from the autorotation. The pilot stated that he did not add power at that point and that there was inadequate rotor inertia to dampen the landing, even though he applied full collective deflection. The helicopter hit hard and sustained substantial damage. The aft portion of the tail boom and tail rotor separated due to a main rotor blade contact and the skids were damaged.
NTSB Probable Cause Narrative
The pilot’s inadequate use of throttle during the practice autorotation that resulted in a hard landing.
Event Information
| Type of Event | Accident |
| Event Date | 1/15/2011 |
| Event Day of the Week | Saturday |
| Time of Event | 1300 |
| Event Time Zone | Mountain Standard Time |
| Event City | Three Forks |
| Event State | MONTANA |
| Event Country | -- |
| Zipcode of the event site | 59752 |
| Event Date Year | 2011 |
| Event Date Month | 1 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | 455230N |
| Event Location Longitude | 1113424W |
| Event Location Airport | Three Forks |
| Event Location Nearest Airport ID | 9S5 |
| Indicates whether the acc/inc occurred off or on an airport | On Airport |
| Distance from airport in statute miles | 0 |
| Degrees magnetic from airport | -- |
| Airport Elevation | -- |
| Weather Briefing Completeness | -- |
| Investigator's weather source | Weather Observation Facility |
| Time of the weather observation | 1256 Mountain Standard Time |
| Direction of event from weather observation facility (degrees) | -- |
| Weather Observation Facility ID | KBZN |
| Elevation of weather observation facility | -- |
| Distance of event from weather observation facility (units?) | -- |
| Time Zone of the weather observation | MST |
| Lighting Conditions | Day |
| Lowest Ceiling Height | -- |
| Lowest Non-Ceiling Height | 7500 |
| 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) | 5 |
| Dew Point at event time (in degress fahrenheit) | -3 |
| Wind Direction (degrees magnetic) | 310 |
| Variable Wind Indicator | Wind direction could be determined |
| Wind Speed (knots) | 4 |
| Wind Velocity Indicator | -- |
| Wind Gust Indicator | Not Gusting |
| Wind Gust (knots) | -- |
| Altimeter Setting at event time (in. Hg) | 30.11 |
| Density Altitude (feet) | -- |
| Intensity of Precipitation | -- |
| METAR weather report | -- |
| Event Highest Injury | None |
| On Ground, Fatal Injuries | -- |
| On Ground, Minor Injuries | -- |
| On Ground, Serious Injuries | -- |
| Injury Total Fatal | -- |
| Injury Total Minor | -- |
| Injury Total None | 2 |
| Injury Total Serious | -- |
| Injury Total All | -- |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 28171 |
| 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 | Feb 23 2011 12:52PM |
| User who most recently changed record | coos |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N78BR |
| NTSB Number | WPR11CA101 |
| 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 | 206B3 |
| Aircraft Series Identifier | -- |
| Aircraft Serial Number | 4001 |
| Certified Max Gross Weight | 3200 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | -- |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| 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 | Annual |
| Date of Last Inspection | Jun 23 2010 12:00AM |
| Airframe hours since last inspection | -- |
| Airframe Hours | 2701 |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | No |
| ELT Type | Unknown |
| Aircraft Owner Name | Skymission LLC |
| Aircraft Owner Street Address | -- |
| Aircraft Owner City | Bozeman |
| Aircraft Owner State | MT |
| Aircraft Owner Country | USA |
| Aircraft Owner Zipcode | 59715 |
| Operator is an individual? | No |
| Operator Name | Skymission LLC |
| Operator Same as Owner? | Yes |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | Yes |
| Operator Street Address | -- |
| Operator City | Bozeman |
| Operator State | MT |
| Operator Country | USA |
| Operator Zip code | 59715 |
| 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 | BZN |
| Departure City | Bozeman |
| Departure State | MT |
| Departure Country | USA |
| Departure Time | 1215 |
| Departure Time Zone | MST |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | BZN |
| Destination City | Bozeman |
| Destination State | MT |
| Destination Country | USA |
| Specific Phase of Flight | -- |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Feb 23 2011 12:52PM |
| User who most recently changed record | coos |
| Since inspection or accident | Time of Accident |
| Event Location Runway Number and Location | 02 |
| Runway Length | 5100 |
| Runway Width | 60 |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |