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NTSB Report
July 18, 1989 · Bell 206B · N1086C
Duchesne, UT
Overview
Report Status
Probable Cause
Event Type
Accident
Date
July 18, 1989
Injury Outcomes
3 injuries (3 fatalities)
Location
Duchesne, UT
Aircraft
Bell 206B
Tail Number
N1086C
Operator
Rocky Mountain Helicopter
Injuries
Fatal
Aircraft Damage
Destroyed
NTSB Number
DEN89FA175
THE HELICOPTER WAS BEING OPERATED ON A SPECIALIZED POWER LINE PATROL TO CONDUCT 'KORONA MEASURING' FOR A 'LEAKAGE' CHECK OF THE TRANSMISSION LINE. THIS CHECK REQUIRED THAT THE HELICOPTER BE FLOWN AT A CONSTANT ALTITUDE & SPEED, & AT A DISTANCE OF 100' OR LESS FROM THE POWER LINE. WHILE PATROLLING EASTBOUND, THE MAIN ROTOR STRUCK THE NORTH STATIC LINE. SUBSEQUENTLY, THE MAIN ROTOR, SWASH PLATE, & TRANSMISSION/ROTOR MAST SEPARATED & THE HELICOPTER CRASHED. WHEN THE HELICOPTER DID NOT RETURN FROM THE PATROL, A SEARCH WAS ORGANIZED. THE WRECKAGE WAS FOUND THE NEXT DAY AT 1045 MDT. THE PLT & 1 PAX WERE DECEASED, BUT THE OTHER PAX APPEARED TO BE ALIVE; HOWEVER, HE DIED BEFORE MEDICAL ASSISTANCE ARRIVED. NO PREIMPACT PART FAILURE OR MALFUNCTION OF THE HELICOPTER WAS FOUND. AN INVESTIGATION REVEALED THIS WAS THE PILOT'S 1ST POWER LINE PATROL. ON HIS APPLICATION FOR RECENT EMPLOYMENT WITH THE COMPANY, HE INDICATED HE HAD OVER 1900 HRS OF FLT TIME; HOWEVER, ONLY 585 HRS OF FLT TIME COULD BE VERIFIED. HE DID NOT RCV MISSION TRAINING FOR THIS FLT.
NTSB Probable Cause
THE PILOT FAILED TO MAINTAIN CLEARANCE FROM THE POWER LINE. CONTRIBUTING FACTORS WERE: LACK OF MISSION TRAINING PROVIDED BY THE COMPANY/OPERATOR, THE PILOT'S LACK OF EXPERIENCE IN THIS TYPE OF OPERATION, HIS LACK OF FAMILIARITY WITH THE GEOGRAPHIC AREA, AND THE COMPANY/OPERATOR'S INADEQUATE SUBSTANTIATION PROCESS TO ASSURE THE EXPERIENCE LEVEL OF NEWLY HIRED PILOTS.
Full Narrative
THE HELICOPTER WAS BEING OPERATED ON A SPECIALIZED POWER LINE PATROL TO CONDUCT 'KORONA MEASURING' FOR A 'LEAKAGE' CHECK OF THE TRANSMISSION LINE. THIS CHECK REQUIRED THAT THE HELICOPTER BE FLOWN AT A CONSTANT ALTITUDE & SPEED, & AT A DISTANCE OF 100' OR LESS FROM THE POWER LINE. WHILE PATROLLING EASTBOUND, THE MAIN ROTOR STRUCK THE NORTH STATIC LINE. SUBSEQUENTLY, THE MAIN ROTOR, SWASH PLATE, & TRANSMISSION/ROTOR MAST SEPARATED & THE HELICOPTER CRASHED. WHEN THE HELICOPTER DID NOT RETURN FROM THE PATROL, A SEARCH WAS ORGANIZED. THE WRECKAGE WAS FOUND THE NEXT DAY AT 1045 MDT. THE PLT & 1 PAX WERE DECEASED, BUT THE OTHER PAX APPEARED TO BE ALIVE; HOWEVER, HE DIED BEFORE MEDICAL ASSISTANCE ARRIVED. NO PREIMPACT PART FAILURE OR MALFUNCTION OF THE HELICOPTER WAS FOUND. AN INVESTIGATION REVEALED THIS WAS THE PILOT'S 1ST POWER LINE PATROL. ON HIS APPLICATION FOR RECENT EMPLOYMENT WITH THE COMPANY, HE INDICATED HE HAD OVER 1900 HRS OF FLT TIME; HOWEVER, ONLY 585 HRS OF FLT TIME COULD BE VERIFIED. HE DID NOT RCV MISSION TRAINING FOR THIS FLT.
Flight
Event TypeAccident
Event Time13:15 MDT
Nearest Airport0nm N
Runway0
Runway Length0
Runway Width0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftBell 206B
Tail NumberN1086C
Aircraft CategoryHeli
DamageDestroyed
OperatorRocky Mountain Helicopter
Operating RulePart 91
Engines1
Engine TypeTurboshaft
Engine DetailsAllison · 250-C20B · Turboshaft · 317
Seats4
People & Injuries
Injury Summary3 injuries (3 fatalities)
Fatal3
Serious0
Minor0
Uninjured0
Total3
Crew 1Age 34 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind270° @ 3 kt
Visibility60 sm
CeilingNone
Temperature / Dew Point0 C
Altimeter0
Weather SourceWIT