# NTSB ATL84LA205: Sikorsky CH-19E, N4721, Iva, SC, June 20, 1984

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: June 20, 1984, 07:00 local (11:00 UTC)
- Place: Iva, SC
- Coordinates: 34.300231, -82.660469 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=34.3002&lon=-82.6605&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 6482
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL84LA205
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/6482/pdf
- Page: https://openairdocs.org/ntsb/ATL84LA205

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Loss of control - on ground/water, takeoff
  - landing gear,main gear strut - pressure too low (contributing factor)
  - maintenance,service of aircraft/equipment - improper (contributing factor)
  - terrain condition - rough/uneven (contributing factor)
  - operation with known deficiencies in equipment - continued, pilot in command (cause)
  - fuselage - vibration (cause)
- Airframe/component/system failure/malfunction, takeoff
  - misc rotorcraft,tail boom - overload

## Analysis

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.

## Aircraft

- Registration: [N4721](https://openairdocs.org/deregistered/N4721-2013-08-19), registration cancelled 2013-08-19, S/N 129028, built 1952 (OpenAirDocs)
- Reported make and model: SIKORSKY CH-19E
- Registry model: [Sikorsky CH-19E](https://openairdocs.org/model/sikorsky-ch-19e) (registry code 8141616) (OpenAirDocs)
- Registry engine: [Wright R-1300 series](https://openairdocs.org/engine/wright-r-1300-series) (registry code 67060, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 129028
- Airframe hours: 4319
- Engines: WRIGHT R-1300-3 800 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Ag-Rotor, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, April 18, 1984, 79 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 4,793 total, 79 in this make and model, 2,988 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: 360° at 4 knots
- Visibility: 5 statute miles
- Lowest ceiling: none
- Temperature: 73 °F, dew point 72 °F
- Altimeter: 30.00 inHg
- Observed at: AND, 17 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19840620026009A](https://openairdocs.org/incident/19840620026009A), Jun 20, 1984: Orlhel CH19ESKRSKY, Iva, SC, Substantial damage. During increase in rotor RPM for takeoff a severe lateral vibration occurred. Fuselage broke off at station 255.

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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