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NTSB Report
February 8, 1989 · Bell TH-1L · N204AP
Greenville, FL
Overview
Report Status
Probable Cause
Event Type
Accident
Date
February 8, 1989
Injury Outcomes
No injuries (2 uninjured)
Location
Greenville, FL
Aircraft
Bell TH-1L
Tail Number
N204AP
Operator
Green Mountain Helicopter
Injuries
None
Aircraft Damage
Substantial
NTSB Number
MIA89LA081
FLT EXPERIENCED LOSS OF TRANSMISSION DRIVE AND PERFORMED AN AUTOROTATION INTO TREES. EXAMINATION OF THE TRANSMISSION INDICATED THE SPRAG CLUTCH HAD FAILED AND THAT THE FAILED SPRAG CLUTCH WAS THE IMPROPER CLUTCH FOR THAT ENGINE AND TRANSMISSION. THE CLUTCH HAD BEEN INSTALLED AT TRANSMISSION OVERHAUL 140 HOURS BEFORE THE ACCIDENT.
NTSB Probable Cause
INSTALLATION OF THE IMPROPER SPRAG CLUTCH ASSEMBLY BY THE OWNERS MAINTENANCE PERSONNEL RESULTING IN FAILURE OF THE SPRAG CLUTCH AND THE LOSS OF TRANSMISSION DRIVE.
Full Narrative
FLT EXPERIENCED LOSS OF TRANSMISSION DRIVE AND PERFORMED AN AUTOROTATION INTO TREES. EXAMINATION OF THE TRANSMISSION INDICATED THE SPRAG CLUTCH HAD FAILED AND THAT THE FAILED SPRAG CLUTCH WAS THE IMPROPER CLUTCH FOR THAT ENGINE AND TRANSMISSION. THE CLUTCH HAD BEEN INSTALLED AT TRANSMISSION OVERHAUL 140 HOURS BEFORE THE ACCIDENT.
Flight
Event TypeAccident
Event Time11:25 EST
Nearest Airport0nm N
Runway0
Runway Length0
Runway Width0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftBell TH-1L
Tail NumberN204AP
Aircraft CategoryHeli
DamageSubstantial
OperatorGreen Mountain Helicopter
Operating RulePart 133
Engines1
Engine TypeTurboshaft
Engine DetailsLycoming · T53-L-13B · Turboshaft · 1400
Seats11
People & Injuries
Injury SummaryNo injuries (2 uninjured)
Fatal0
Serious0
Minor0
Uninjured2
Total2
Crew 1Age 38 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind360° @ 4 kt
Visibility6 sm
CeilingNone
Temperature / Dew Point41 C / 36 C
Altimeter30.00 inHg
Observation Time16:48
Weather SourceWFAC