Aircraft Accident/Incident Report

Vernal, Utah 84078
Monday, December 3, 1990 14:45 MST

NTSB Narrative Summary Released at Completion of Accident

THE ACFT DEVELOPED VIBRATIONS IN FLT WITH SEVERE FEEDBACK THROUGH THE CONTROL SYSTEM TO THE CYCLIC STICK. THE PILOT INITIATED AN EMERGENCY LANDING AND LOST CONTROL JUST BEFORE TOUCHDOWN. THE ACFT IMPACTED THE GROUND WHILE SPINNING AND ROLLED OVER. EVIDENCE INDICATED A MALFUNCTION/FAILURE OF A MAIN ROTOR DAMPER.

NTSB Probable Cause Narrative

A MALFUNCTION/FAILURE OF THE HELICOPTER'S MAIN ROTOR LEAD-LAG DAMPER.

Event Information

Type of Event Accident
Event Date 12/3/1990
Event Day of the Week Monday
Time of Event 1445
Event Time Zone Mountain Standard Time
Event City VERNAL
Event State UTAH
Event Country --
Zipcode of the event site 84078
Event Date Year 1990
Event Date Month 12
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 0
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1450 Mountain Standard Time
Direction of event from weather observation facility (degrees) 120
Weather Observation Facility ID VEL
Elevation of weather observation facility 5274
Distance of event from weather observation facility (units?) 19
Time Zone of the weather observation MST
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 40
Air Temperature at event time (in degrees celsius) 1
Dew Point at event time (in degress fahrenheit) -2
Wind Direction (degrees magnetic) 0
Variable Wind Indicator Unknown
Wind Speed (knots) 0
Wind Velocity Indicator Calm
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 0
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury Minor
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor 3
Injury Total None --
Injury Total Serious --
Injury Total All 3
Investigating Agency NTSB
NTSB Docket Number (internal use) 2154
NTSB Notification Source --
NTSB Notification Date Dec 3 1990 12:00AM
NTSB Notification Time 1150
Fiche Number and/or location -used to find docket information 44625
Date of most recent change to record Dec 12 2000 5:37PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N316BS
NTSB Number SEA91LA028
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 None
Aircraft Explosion None
Aircraft Manufacturer's Full Name AEROSPATIALE
Aircraft Model SA316B
Aircraft Series Identifier SA316B
Aircraft Serial Number 5399
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 Unknown
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name
Aircraft Owner Street Address
Aircraft Owner City
Aircraft Owner State
Aircraft Owner Country
Aircraft Owner Zipcode
Operator is an individual? --
Operator Name AVMAN AVIATION HELICOPTER SVC
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 2244 SOUTH 1640 WEST
Operator City WOODS CROSS
Operator State UT
Operator Country
Operator Zip code 84087
Operator Code KBTA
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 1425
Departure Time Zone MST
Destination Same as Local Flt --
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Landing
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 0
Runway Width 0
Sight Seeing flight No
Air Medical Flight No
Medical Flight --