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NTSB Report
June 20, 1984 · Sikorsky CH-19E · N4721
Iva, SC
Overview
Report Status
Preliminary report
Event Type
Accident
Date
June 20, 1984
Injury Outcomes
No injuries (1 uninjured)
Location
Iva, SC
Aircraft
Sikorsky CH-19E
Tail Number
N4721
Injuries
None
Aircraft Damage
Substantial
NTSB Number
ATL84LA205
THE HELICOPTER WAS BEING OPERATED FROM SLOPING TERRAIN. AFTER RETURNING FROM A SPRAY MISSION, THE PLT REMAINED INSIDE THE HELICOPTER WITH THE ENG & ROTOR AT GROUND IDLE WHILE THE GROUND CREW REFILLED THE SPRAY TANK. AFTER COMPLETING THE LOADING OPERATION, THE PLT BEGAN APPLYING POWER TO INCREASE THE ROTOR RPM FOR TAKEOFF. A SEVERE GROUND-RESONANCE TYPE OF VIBRATION DEVELOPED. THE PLT DISENGAGED THE ENG & APPLIED THE ROTOR BRAKE. WHEN THE ROTOR HAD STOPPED & THE ENG WAS SECURED, THE PLT EGRESSED & OBSERVED THAT THE AFT END OF THE TAIL BOOM WAS LAYING ON THE GROUND. NO PRE-ACCIDENT CRACKS OR FAILURES WERE FOUND IN THE TAIL BOOM. SOME COMPONENTS OF THE ROTOR SYS HAD CRACKS, BUT NONE HAD FAILED OR SEPARATED. THE MAIN ROTOR LEAD-LAG DAMPERS WERE REMOVED & CHECKED FOR TIME & ALL WERE WITHIN SPECIFICATIONS. PERSONNEL WHO RECOVERED THE HELICOPTER NOTED THAT THE LEFT FRONT LANDING GEAR STRUT WAS FLAT & THE LEFT REAR MAIN LANDING GEAR STRUT WAS LOW. THEY ESTIMATED THE TERRAIN WAS SLOPING 10 DEGS.
Full Narrative
THE HELICOPTER WAS BEING OPERATED FROM SLOPING TERRAIN. AFTER RETURNING FROM A SPRAY MISSION, THE PLT REMAINED INSIDE THE HELICOPTER WITH THE ENG & ROTOR AT GROUND IDLE WHILE THE GROUND CREW REFILLED THE SPRAY TANK. AFTER COMPLETING THE LOADING OPERATION, THE PLT BEGAN APPLYING POWER TO INCREASE THE ROTOR RPM FOR TAKEOFF. A SEVERE GROUND-RESONANCE TYPE OF VIBRATION DEVELOPED. THE PLT DISENGAGED THE ENG & APPLIED THE ROTOR BRAKE. WHEN THE ROTOR HAD STOPPED & THE ENG WAS SECURED, THE PLT EGRESSED & OBSERVED THAT THE AFT END OF THE TAIL BOOM WAS LAYING ON THE GROUND. NO PRE-ACCIDENT CRACKS OR FAILURES WERE FOUND IN THE TAIL BOOM. SOME COMPONENTS OF THE ROTOR SYS HAD CRACKS, BUT NONE HAD FAILED OR SEPARATED. THE MAIN ROTOR LEAD-LAG DAMPERS WERE REMOVED & CHECKED FOR TIME & ALL WERE WITHIN SPECIFICATIONS. PERSONNEL WHO RECOVERED THE HELICOPTER NOTED THAT THE LEFT FRONT LANDING GEAR STRUT WAS FLAT & THE LEFT REAR MAIN LANDING GEAR STRUT WAS LOW. THEY ESTIMATED THE TERRAIN WAS SLOPING 10 DEGS.
Flight
Event TypeAccident
Event Time07:00 EDT
Nearest Airport0nm N
Runway0
Flight Plan FiledNone
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftSikorsky CH-19E
Tail NumberN4721
Aircraft CategoryHeli
DamageSubstantial
Operating RulePart 137
Engines1
Engine TypeReciprocating
Engine DetailsWright · R-1300-3 · Reciprocating · 800
Seats2
People & Injuries
Injury SummaryNo injuries (1 uninjured)
Fatal0
Serious0
Minor0
Uninjured1
Total1
Crew 1Age 41 · Second Class
Conditions
ConditionsVMC
LightDaylight
Wind360° @ 4 kt
Visibility5 sm
CeilingNone
Altimeter30.00 inHg
Observation Time10:55
Weather SourceWFAC