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NTSB Report
November 26, 1987 · Hughes 369HS · N77DJ
Lihue, Kauai, HI
Overview
Report Status
Probable Cause
Event Type
Accident
Date
November 26, 1987
Injury Outcomes
3 injuries (3 serious injuries)
Location
Lihue, Kauai, HI
Aircraft
Hughes 369HS
Tail Number
N77DJ
Operator
Kauai Helicopters
Injuries
Serious
Aircraft Damage
Substantial
NTSB Number
LAX88LA059
THE PILOT, WHO WAS ALSO A CERTIFICATED AIRFRAME & POWERPLANT MECH, RECENTLY CHANGED THE TAILBOOM ASSY. AT THE TIME OF THE ACCIDENT HE WAS CONDUCTING A MAINTENANCE TEST FLIGHT. THE PILOT EXECUTED ONE AUTOROTATION WITH A POWER RECOVERY. THE PLT REENTERED THE TRAFFIC PATTERN. GND WITNESSES REPTD THAT WHEN THE HELICOPTER ENTERED THE BASE LEG THEY HEARD AN EXPLOSIVE SOUND FOLLOWED BY THE TAILBOOM ASSY SEPARATING FROM THE HELICOPTER. THE WRECKAGE EXAM DSCLSD THE MAIN ROTOR BLADE STRUCK THE TAILBOOM. THE TAIL ROTOR BLADES WENT OUT OF TRACK AND STRUCK THE VERTICAL FINS, SEPARATING THE UPPER VERTICAL FIN. NO EVIDENCE OF ANY PREEXISTING MALFUNCTIONS WAS FOUND. THE MAIN ROTOR BLADES EXHIBITED LOW ROTOR RPM DAMAGE.
NTSB Probable Cause
PILOT FAILURE TO MAINTAIN ADEQUATE MAIN ROTOR RPM.
Full Narrative
THE PILOT, WHO WAS ALSO A CERTIFICATED AIRFRAME & POWERPLANT MECH, RECENTLY CHANGED THE TAILBOOM ASSY. AT THE TIME OF THE ACCIDENT HE WAS CONDUCTING A MAINTENANCE TEST FLIGHT. THE PILOT EXECUTED ONE AUTOROTATION WITH A POWER RECOVERY. THE PLT REENTERED THE TRAFFIC PATTERN. GND WITNESSES REPTD THAT WHEN THE HELICOPTER ENTERED THE BASE LEG THEY HEARD AN EXPLOSIVE SOUND FOLLOWED BY THE TAILBOOM ASSY SEPARATING FROM THE HELICOPTER. THE WRECKAGE EXAM DSCLSD THE MAIN ROTOR BLADE STRUCK THE TAILBOOM. THE TAIL ROTOR BLADES WENT OUT OF TRACK AND STRUCK THE VERTICAL FINS, SEPARATING THE UPPER VERTICAL FIN. NO EVIDENCE OF ANY PREEXISTING MALFUNCTIONS WAS FOUND. THE MAIN ROTOR BLADES EXHIBITED LOW ROTOR RPM DAMAGE.
Flight
Event TypeAccident
Event Time08:10 HST
Nearest AirportLIHUE (0nm N)
Runway3
Runway Length6000 ft
Runway Width100 ft
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftHughes 369HS
Tail NumberN77DJ
Aircraft CategoryHeli
DamageSubstantial
OperatorKauai Helicopters
Operating RulePart 91
Engines1
Engine TypeTurboshaft
Engine DetailsAllison · 250-C20B · Turboshaft · 375
Seats5
People & Injuries
Injury Summary3 injuries (3 serious injuries)
Fatal0
Serious3
Minor0
Uninjured0
Total3
Crew 1Age 42 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind80° @ 18 kt
Visibility14 sm
CeilingNone
Temperature / Dew Point68 F
Altimeter30.00 inHg
Observation Time17:55
Weather SourceWFAC