Individually Owned: 150,657
Corporate Owned: 137,281
Aircraft Accident/Incident Report
Meeteetse, Wyoming 82433
Sunday, August 19, 1990 18:00 MDT
NTSB Narrative Summary Released at Completion of Accident
APPROXIMATELY 2 MINUTES INTO THE FLIGHT, THE PILOT EXPERIENCED A SLIGHT 1 TO 1 VIBRATION THROUGH THE CYCLIC. THIS TYPE VIBRATION IS ASSOCIATED WITH MAIN ROTOR DAMPERS AND THE PILOT 'STIRRED' THE CYCLIC IN AN EFFORT TO PURGE AIR OUT OF THE BLADE DAMPERS. THIS ELIMINATED THE PROBLEM, HOWEVER, IT RECURRED AND COULD NOT BE ELIMINATED. THE VIBRATION INCREASED TO THE POINT OF LOSS OF CONTROL. AN EMERGENCY LANDING WAS ATTEMPTED WITH TOUCHDOWN OCCURRING AT ABOUT 60 KNOTS. THE HELICOPTER CAME TO REST INVERTED AND WAS LARGELY CONSUMED BY POST-IMPACT FIRE. METALLURGICAL ANALYSIS ON A FAILED BLADE RESTRAINING CABLE REVEALED A CATASTROPHIC FAILURE IN A LOW CYCLE FATIGUE MODE CONSISTENT WITH A SECONDARY CAUSE, AND DUE TO SHORT TERM VIBRATIONS. IN ADDITION TO FATIGUE, THERE WAS EVIDENCE OF PLASTIC DEFORMATION DUE TO VIBRATORY LOADS FROM THE DAMPER SYSTEMS. FIRE DAMAGE PREVENTED ADDITIONAL FAILURE ANALYSIS.
NTSB Probable Cause Narrative
A MAIN ROTOR HEAD BLADE DAMPENER FAILURE. A FACTOR IN THE ACCIDENT WAS THE SUBSEQUENT FAILURE OF A BLADE RESTRAINING CABLE.
Event Information
| Type of Event | Accident |
| Event Date | 8/19/1990 |
| Event Day of the Week | Sunday |
| Time of Event | 1800 |
| Event Time Zone | Mountain Daylight Time |
| Event City | MEETEETSE |
| Event State | WYOMING |
| Event Country | -- |
| Zipcode of the event site | 82433 |
| Event Date Year | 1990 |
| Event Date Month | 8 |
| MidAir Collision Indicator | No |
| On Ground Collision occurred ? | No |
| Event Location Latitude | |
| Event Location Longitude | |
| 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 | 0 |
| Degrees magnetic from airport | 0 |
| Airport Elevation | -- |
| Weather Briefing Completeness | Unknown |
| Investigator's weather source | Pilot |
| Time of the weather observation | 0 |
| Direction of event from weather observation facility (degrees) | 0 |
| Weather Observation Facility ID | |
| Elevation of weather observation facility | 0 |
| Distance of event from weather observation facility (units?) | 0 |
| Time Zone of the weather observation | |
| Lighting Conditions | Day |
| Lowest Ceiling Height | 6000 |
| Lowest Non-Ceiling Height | 0 |
| Sky/Lowest/Cloud Conditions | Unknown |
| Sky Condition for Lowest Ceiling | Overcast |
| Visibility Runway Visual Range (Feet) | 0 |
| Visibility Runway Visual Value (Statute Miles) | 0 |
| Visibility (Statute Miles) | 7 |
| Air Temperature at event time (in degrees celsius) | -18 |
| Dew Point at event time (in degress fahrenheit) | -18 |
| Wind Direction (degrees magnetic) | 240 |
| Variable Wind Indicator | Unknown |
| Wind Speed (knots) | 10 |
| Wind Velocity Indicator | Unknown |
| Wind Gust Indicator | Unknown |
| Wind Gust (knots) | 0 |
| Altimeter Setting at event time (in. Hg) | -- |
| Density Altitude (feet) | 0 |
| Intensity of Precipitation | Light |
| METAR weather report | -- |
| Event Highest Injury | Serious |
| On Ground, Fatal Injuries | 0 |
| On Ground, Minor Injuries | 0 |
| On Ground, Serious Injuries | 0 |
| Injury Total Fatal | -- |
| Injury Total Minor | 4 |
| Injury Total None | -- |
| Injury Total Serious | 3 |
| Injury Total All | 7 |
| Investigating Agency | NTSB |
| NTSB Docket Number (internal use) | 1921 |
| NTSB Notification Source | -- |
| NTSB Notification Date | Aug 20 1990 12:00AM |
| NTSB Notification Time | 900 |
| Fiche Number and/or location -used to find docket information | 43816 |
| Date of most recent change to record | Dec 18 2002 11:28AM |
| User who most recently changed record | NTSB\GIUV |
| Basic weather conditions | Visual Meteorological Cond |
| FAA District Office | -- |
Aircraft Involved |
|
|---|---|
Aircraft #1 |
|
| Aircraft Registration Number | N83776 |
| NTSB Number | DEN90FA172 |
| Missing Aircraft Indicator | N |
| Federal Aviation Reg. Part | Part 135: Air Taxi & Commuter |
| Type of Flight Plan filed | None |
| Flight plan Was Activated? | -- |
| Damage | Destroyed |
| Aircraft Fire | Ground |
| Aircraft Explosion | Ground |
| Aircraft Manufacturer's Full Name | AEROSPATIALE |
| Aircraft Model | SA316B |
| Aircraft Series Identifier | SA316B |
| Aircraft Serial Number | 1827 |
| Certified Max Gross Weight | 4850 |
| Aircraft Category | Helicopter |
| Aircraft Registration Class | U.S. Registered/U.S. Soil |
| Aircraft is a homebuilt? | No |
| Flight Crew Seats | -- |
| Cabin Crew Seats | -- |
| Passenger Seats | -- |
| Total number of seats on the aircraft | 7 |
| Number of Engines | 1 |
| Fixed gear or retractable gear | Fixed |
| Aircraft, Type of Last Inspection | Unknown |
| Date of Last Inspection | -- |
| Airframe hours since last inspection | 0 |
| Airframe Hours | -- |
| ELT Installed | Yes |
| ELT Activated | Yes |
| ELT Aided Location of Event Site | Unknown |
| ELT Type | -- |
| Aircraft Owner Name | UNKNOWN |
| Aircraft Owner Street Address | |
| Aircraft Owner City | |
| Aircraft Owner State | |
| Aircraft Owner Country | |
| Aircraft Owner Zipcode | |
| Operator is an individual? | -- |
| Operator Name | ROCKY MOUNTAIN HELICOPTER |
| Operator Same as Owner? | No |
| Operator Is Doing Business As | -- |
| Operator Address Same as Owner? | No |
| Operator Street Address | P.O. BOX 1337 |
| Operator City | PROVO |
| Operator State | UT |
| Operator Country | |
| Operator Zip code | 84603 |
| Operator Code | DYRA |
| Owner has at least one certificate | Yes - certificate holder |
| Other Operator of large aircraft? | No |
| Certified for Part 133 or 137 Operation | External Load |
| Operator Certificate Number | -- |
| Indicates whether an air carrier operation was scheduled or not | Non-scheduled |
| Indicates Domestic or International Flight | Domestic |
| Operator carrying Pax/Cargo/Mail | Passenger Only |
| Type of Flying (Per_Bus / Primary) | Unknown |
| Second Pilot on Board | No |
| Departure Point Same as Event | Yes |
| Departure Airport Code | |
| Departure City | |
| Departure State | |
| Departure Country | |
| Departure Time | 1755 |
| Departure Time Zone | MDT |
| Destination Same as Local Flt | dest & departure same, accident can occur anywhere |
| Destination Airport Code | NONE |
| Destination City | |
| Destination State | |
| Destination Country | |
| Specific Phase of Flight | Descent |
| Report sent to ICAO? | -- |
| Evacuation occurred | -- |
| Date of most recent change to record | Jan 2 2001 10:35AM |
| User who most recently changed record | dbo |
| Since inspection or accident | -- |
| Event Location Runway Number and Location | 0 |
| Runway Length | -- |
| Runway Width | -- |
| Sight Seeing flight | No |
| Air Medical Flight | No |
| Medical Flight | -- |