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NTSB Report
January 5, 1984 · Hiller UH-12E · N4027K
Mapleton, OR
Overview
Report Status
Preliminary report
Event Type
Accident
Date
January 5, 1984
Injury Outcomes
1 injury (1 minor injury)
Location
Mapleton, OR
Aircraft
Hiller UH-12E
Tail Number
N4027K
Injuries
Minor
Aircraft Damage
Substantial
NTSB Number
SEA84LA034
WHILE APPROACHING THE SPRAY AREA, THE ACFT WAS IN A LEVEL ATTITUDE AT 20 TO 25 MPH & ABOUT 100 FT AGL WHEN THE PLT HEARD A LOUD BANG & NOTED A LOSS OF POWER. HE ATTEMPTED AN AUTOROTATIVE LANDING. DURING TOUCHDOWN ON HILLY TERRAIN, THE ACFT ROLLED TO THE RIGHT & CAME TO REST INVERTED ON A STEEP SLOPE. A TEARDOWN OF THE ENG REVEALED THAT A SPUR ADAPTER GEARSHAFT, PN 6890482, & A COMPRESSOR COUPLING ADAPTER, PN 6871472, HAD FAILED. FAILURE OF THE SPUR ADAPTER GEARSHAFT WAS DUE TO FATIGUE WHICH ORIGINATED AT AN AREA OF HEAVY WEAR ON THE LOAD SIDE OF THE FORWARD SPLINES.
Full Narrative
WHILE APPROACHING THE SPRAY AREA, THE ACFT WAS IN A LEVEL ATTITUDE AT 20 TO 25 MPH & ABOUT 100 FT AGL WHEN THE PLT HEARD A LOUD BANG & NOTED A LOSS OF POWER. HE ATTEMPTED AN AUTOROTATIVE LANDING. DURING TOUCHDOWN ON HILLY TERRAIN, THE ACFT ROLLED TO THE RIGHT & CAME TO REST INVERTED ON A STEEP SLOPE. A TEARDOWN OF THE ENG REVEALED THAT A SPUR ADAPTER GEARSHAFT, PN 6890482, & A COMPRESSOR COUPLING ADAPTER, PN 6871472, HAD FAILED. FAILURE OF THE SPUR ADAPTER GEARSHAFT WAS DUE TO FATIGUE WHICH ORIGINATED AT AN AREA OF HEAVY WEAR ON THE LOAD SIDE OF THE FORWARD SPLINES.
Flight
Event TypeAccident
Event Time14:50 PST
Nearest Airport0nm N
Runway0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftHiller UH-12E
Tail NumberN4027K
Aircraft CategoryHeli
DamageSubstantial
Operating RulePart 137
Engines1
Engine TypeTurboshaft
Engine DetailsAllison · 250-C20B · Turboshaft · 305
Seats3
People & Injuries
Injury Summary1 injury (1 minor injury)
Fatal0
Serious0
Minor1
Uninjured0
Total1
Crew 1Age 38 · Second Class
Conditions
ConditionsVMC
LightDaylight
WindCalm
Visibility5 sm
CeilingNone
Temperature / Dew Point50 / 0 C
Altimeter0
Weather SourcePILO