# NTSB ATL83LA160: Bell 47G-4A, N4749R, Charleston, WV, April 13, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 13, 1983, 11:15 local (16:15 UTC)
- Place: Charleston, WV
- Coordinates: 38.370105, -81.560386 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.3701&lon=-81.5604&mi=10
- Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 6050
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL83LA160
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/6050/pdf
- Page: https://openairdocs.org/ntsb/ATL83LA160

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, approach
  - engine assembly,other - fatigue (cause)
- Forced landing, landing - flare/touchdown
  - autorotation - performed, pilot in command (contributing factor)
- In flight collision with terrain/water, landing - flare/touchdown
  - terrain condition - high obstruction(s) (contributing factor)
  - terrain condition - rough/uneven (contributing factor)
  - maneuver - performed, pilot in command (contributing factor)
  - rotor rpm - not possible, pilot in command (contributing factor)

## Analysis

DURING AN APPROACH TO LAND, THE ENGINE LOST POWER AT APRX 500 FT AGL. THE PLT REPORTED THAT DURING AN AUTOROTATIVE LANDING, HE HAD TO MANEUVER TO AVOID TREES & A RIDGE IN ORDER TO LAND IN A SUITABLE AREA. DURING THIS TIME, ROTOR RPM DROPPED & A CRASH LANDING OCCURRED. A TEARDOWN OF THE ENGINE REVEALED THAT THE TIMING GEAR, PN 67687, HAD FAILED & A TOOTH HAD SEPARATED. ALSO, THE WOODRUFF KEY, PN STD-858, HAD FAILED. A METALURGICAL EXAMINATION REVEALED EVIDENCE OF FATIGUE ON BOTH PARTS. FAILURE OF THE TIMING GEAR ORIGINATED AT AN INNER CORNER OR THE GEAR KEYWAY. THE ENGINE HAD ACCUMULATED 613 HRS OF FLT TIME SINCE MAJOR OVERHAUL.

## Aircraft

- Registration: [N4749R](https://openairdocs.org/deregistered/N4749R-2012-12-13), registration cancelled 2012-12-13, S/N 7650, built 1968 (OpenAirDocs)
- Reported make and model: BELL 47G-4A
- Registry model: [Bell 47G-4A](https://openairdocs.org/model/bell-47g-4a) (registry code 1181031) (OpenAirDocs)
- Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 7650
- Airframe hours: 4123
- Engines: LYCOMING VO-540-B1B3 280 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial observation, Part 91
- Operator: Appalachian Power Company
- Registered owner: Cincinnati Airways, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: AAIP, August 12, 1982, 613 hours before
- Departed: ROANOKE, VA
- Airport: CRW, Kanawha, runway 33, 4,750 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; commercial; airplane ratings: single-engine land; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 4,570 total, 639 in this make and model, 4,474 as pilot in command, 263 in the last 90 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 140° at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: 5,000 ft broken
- Temperature: 63 °F, dew point 37 °F
- Altimeter: 30.00 inHg
- Observed at: CRW

## 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 19830413014049A](https://openairdocs.org/incident/19830413014049A), Apr 13, 1983: Bell 47G4A, Charleston, WV, Substantial damage. Engine quit approaching airport. Crash landed on a railroad track. Crankshaft timing gear had fatigue broken.

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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