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NTSB Report
August 14, 1990 · Bell UH-1B · N64789
Bieber, CA
Overview
Report Status
Probable Cause
Event Type
Accident
Date
August 14, 1990
Injury Outcomes
1 injury (1 serious injury)
Location
Bieber, CA
Aircraft
Bell UH-1B
Tail Number
N64789
Operator
Intermountain Air Services
Injuries
Serious
Aircraft Damage
Substantial
NTSB Number
LAX90DXQ04
THE PILOT WAS FLYING A FIRE FIGHTING MISSION AND WAS APPROACHING SOUTHERLY ASCENDING TERRAIN FROM THE EAST. THE AIRCRAFT APPROACHED THE TERRAIN AND SLOWED TO MAKE A WATER DROP. AS IT SLOWED THE TAIL TURNED TO THE LEFT AND THE HELICOPTER LOST ALTITUDE AND SETTLED INTO THE TREES. THE PILOT HEARD THE LOW RPM AUDIO AND SAW THE LOW RPM WARNING LIGHT. HE ATTEMPTED TO RELEASE THE WATER LOAD. EXAMINATION OF THE ENGINE AND ENGINE COMPONENTS REVEALED NO EVIDENCE OF A MALFUNCTION OR FAILURE. THE TEMPERATURE REPORTEDLY WAS BETWEEN 82 TO 86 DEGREES F WITH THE WIND FROM THE NORTH AT 5 TO 8 KNOTS.
NTSB Probable Cause
THE PILOT'S FAILURE TO MAINTAIN AIRCRAFT CONTROL WHEN INTENTIONALLY SLOWING HIS AIRCRAFT TO OFF LOAD WATER ON FIRE. CONTRIBUTING TO THE ACCIDENT WAS THE PILOT'S FAILURE TO ARM AND RELEASE THE EXTERNAL LOAD.
Full Narrative
THE PILOT WAS FLYING A FIRE FIGHTING MISSION AND WAS APPROACHING SOUTHERLY ASCENDING TERRAIN FROM THE EAST. THE AIRCRAFT APPROACHED THE TERRAIN AND SLOWED TO MAKE A WATER DROP. AS IT SLOWED THE TAIL TURNED TO THE LEFT AND THE HELICOPTER LOST ALTITUDE AND SETTLED INTO THE TREES. THE PILOT HEARD THE LOW RPM AUDIO AND SAW THE LOW RPM WARNING LIGHT. HE ATTEMPTED TO RELEASE THE WATER LOAD. EXAMINATION OF THE ENGINE AND ENGINE COMPONENTS REVEALED NO EVIDENCE OF A MALFUNCTION OR FAILURE. THE TEMPERATURE REPORTEDLY WAS BETWEEN 82 TO 86 DEGREES F WITH THE WIND FROM THE NORTH AT 5 TO 8 KNOTS.
Flight
Event TypeAccident
Event Time17:58 PDT
Nearest Airport0nm N
Runway0
Runway Length0
Runway Width0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftBell UH-1B
Tail NumberN64789
Aircraft CategoryHeli
DamageSubstantial
OperatorIntermountain Air Services
Operating RulePart 133
Engines1
Engine TypeTurboshaft
Engine DetailsLycoming · T53-L11 · Turboshaft · 1100
Seats2
People & Injuries
Injury Summary1 injury (1 serious injury)
Fatal0
Serious1
Minor0
Uninjured0
Total1
Crew 1Age 50 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind270° @ 8 kt
Visibility6 sm
CeilingNone
Temperature / Dew Point43 C
Altimeter29.00 inHg
Observation Time00:50
Weather SourceWFAC