Sikorsky CH-19E N4721

Summary

On 20 June 1984 at about 11:00 local time, a Sikorsky CH-19E registered N4721 was involved in an accident near Iva, South Carolina, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. No probable cause statement is available for this record.

Date

20 June 1984 at 11:00

Classification

Accident

Location

Iva, South Carolina, United States

Coordinates

34.3002, -82.6605

Aircraft

Sikorsky CH-19E

Registration

N4721

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ATL84LA205

Nobody was injured.

The NTSB has not published a probable cause for this record. No probable cause statement is present in the source data.

Nothing about the cause is stated here that is not in the source record.

Read the full NTSB 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.

Quoted verbatim from the NTSB record.