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NTSB Report
October 4, 1991 · Robinson R22B · N900AB
Honolulu, HI
Overview
Report Status
Probable Cause
Event Type
Accident
Date
October 4, 1991
Injury Outcomes
No injuries (2 uninjured)
Location
Honolulu, HI
Aircraft
Robinson R22B
Tail Number
N900AB
Operator
Makani Helicopters
Injuries
None
Aircraft Damage
Substantial
NTSB Number
LAX92LA005
ACCORDING TO STATEMENTS FROM BOTH THE INSTRUCTOR AND STUDENT, THE FLIGHT WAS PRACTICING PINNACLE APPROACHES IN A MOUNTAINOUS AREA. THE INSTRUCTOR SAID HE PERFORMED A HIGH RECONNAISSANCE OF THE SPOT, AND THEN THE FLIGHT ENCOUNTERED A DOWN DRAFT DURING THE FINAL APPROACH TO THE PEAK. THE INSTRUCTOR SAID HE PERFORMED A RIGHT PEDDLE TURN TO FLY DOWN THE SLOPE OVER A STREAM. THE LOW ROTOR HORN CAME ON AND THE INSTRUCTOR SAID HE ATTEMPTED TO GET THE ROTOR RPM BACK INTO THE GREEN ARC BUT BEFORE HIS CONTROL INPUTS WERE EFFECTIVE THE MAIN ROTOR BLADE COLLIDED WITH TREES ON THE STREAM BANK AND THE HELICOPTER CRASHED INTO THE WATER.
NTSB Probable Cause
THE IMPROPER USE OF THE FLIGHT CONTROLS BY THE INSTRUCTOR PILOT ND THE FAILURE TO MAINTAIN PROPER ROTOR RPM.
Full Narrative
ACCORDING TO STATEMENTS FROM BOTH THE INSTRUCTOR AND STUDENT, THE FLIGHT WAS PRACTICING PINNACLE APPROACHES IN A MOUNTAINOUS AREA. THE INSTRUCTOR SAID HE PERFORMED A HIGH RECONNAISSANCE OF THE SPOT, AND THEN THE FLIGHT ENCOUNTERED A DOWN DRAFT DURING THE FINAL APPROACH TO THE PEAK. THE INSTRUCTOR SAID HE PERFORMED A RIGHT PEDDLE TURN TO FLY DOWN THE SLOPE OVER A STREAM. THE LOW ROTOR HORN CAME ON AND THE INSTRUCTOR SAID HE ATTEMPTED TO GET THE ROTOR RPM BACK INTO THE GREEN ARC BUT BEFORE HIS CONTROL INPUTS WERE EFFECTIVE THE MAIN ROTOR BLADE COLLIDED WITH TREES ON THE STREAM BANK AND THE HELICOPTER CRASHED INTO THE WATER.
Flight
Event TypeAccident
Event Time14:45 HST
Nearest Airport0nm
Runway0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftRobinson R22B
Tail NumberN900AB
Aircraft CategoryHeli
DamageSubstantial
OperatorMakani Helicopters
Operating RulePart 91
Engines1
Engine TypeReciprocating
Engine DetailsLycoming · O-320 · Reciprocating · 160
Seats2
People & Injuries
Injury SummaryNo injuries (2 uninjured)
Fatal0
Serious0
Minor0
Uninjured2
Total2
Crew 1Age 25 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind80° @ 10 kt
Visibility20 sm
CeilingNone
Temperature / Dew Point0 C
Altimeter0
Weather SourcePILO