# NTSB ATL83LA315: Bell 47D1, N68632, Moultrie, GA, August 6, 1983

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: August 6, 1983, 16:30 local (20:30 UTC)
- Place: Moultrie, GA
- Coordinates: 31.159614, -83.770271 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.1596&lon=-83.7703&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 6156
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL83LA315
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/6156/pdf
- Page: https://openairdocs.org/ntsb/ATL83LA315

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering - aerial application
  - rotor drive system,clutch assembly - incorrect (cause)
  - maintenance - improper, other maintenance personnel (cause)
  - rotor drive system,clutch assembly - worn (cause)
  - rotor drive system,clutch assembly - other (cause)
  - rotor rpm - not possible (contributing factor)
- In flight collision with terrain/water, maneuvering - aerial application
  - level off - not possible (contributing factor)
- Roll over, other

## Analysis

AFTER COMPLETING A SWATH RUN, THE PLT PULLED UP, MADE A TURN, THEN STARTED A LET DOWN FOR ANOTHER PASS. AS HE INCREASED POWER, THE ENG RPM WENT FROM 3000 TO 3100. AT THE SAME TIME, THE PLT HEARD A WHINING NOISE AND NOTED THAT THE ROTOR RPM WAS DECREASING. THE PLT WAS UNABLE TO STOP THE DESCENT BEFORE THE HELICOPTER STRUCK THE GROUND. AFTER IMPACTING THE GROUND, THE HELICOPTER BOUNCED, THEN ROLLED OVER. AN EXAM OF THE CENTRIFUGAL CLUTCH ASSEMBLY, PN 47-620-609-1, REVEALED IT HAD AN ESTIMATED 60% CONTACT BETWEEN THE SHOE LININGS AND THE DRUM FACE. A MINIMUM OF 85% CONTACT WAS REQUIRED. THE CLUTCH DID NOT CONFORM TO THE TOE-IN REQUIREMENTS AND NONE OF THE HEELS OF THE CLUTCH SHOES WERE MAKING CONTACT WITH THE DRUM, THE HELICOPTER HAD FLOWN 220 HRS SINCE THE LAST ANNUAL INSPECTION WHEN THE CLUTCH SHOES WERE DEGLAZED 8 THE CLUTCH DRUM WAS CHECKED, AND IT HAD FLOWN APPRX 13 HRS SINCE THE LAST 100 HR INSPECTION.

## Aircraft

- Registration: [N68632](https://openairdocs.org/deregistered/N68632-2013-05-02), registration cancelled 2013-05-02, S/N WH5003, built 1963 (OpenAirDocs)
- Reported make and model: Bell 47D1
- Registry model: [Bell 47D1](https://openairdocs.org/model/bell-47d1) (registry code 1180802) (OpenAirDocs)
- Registry engine: [Franklin 6VS-335 series](https://openairdocs.org/engine/franklin-6vs-335-series) (registry code 27040, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: WH 5003
- Airframe hours: 2482
- Engines: LYCOMING VO-435-A1F 265 horsepower reciprocating
- Damage: Substantial damage
- Fire: Unknown
- Flight: Aerial application, Part 137
- Registered owner: Sunbelt Flyers, Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, April 23, 1983, 13 hours before
- Departed: MUL, MOULTRIE, GA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 708 total, 280 in this make and model, 550 as pilot in command, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 160° at 8 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 93 °F, dew point 72 °F
- Altimeter: 29.00 inHg
- Observed at: ABY, 34 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 19830806039329A](https://openairdocs.org/incident/19830806039329A), Aug 6, 1983: Bell 47D1, Moultrie, GA, Substantial damage. Clutch slipped during spray operation. Lost rotor RPM causing helicopter to hit the ground and roll over.

## Other investigations on N68632 (4)

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.

- [NTSB ATL92LA131](https://openairdocs.org/ntsb/ATL92LA131), Jun 25, 1992: Bell 47D1 (N68632), Centre, AL, substantial damage. Probable cause: THE PILOT'S INADEQUATE VISUAL LOOKOUT, RESULTING IN A COLLISION WITH A WIRE.
- [NTSB MIA79FLD57](https://openairdocs.org/ntsb/MIA79FLD57), Apr 13, 1979: Bell 47-D1 (N68632), Clearwater, FL, destroyed
- [NTSB CHI71DEI52](https://openairdocs.org/ntsb/CHI71DEI52), May 27, 1971: Bell 47D1 (N68632), Bloomdale, OH, substantial damage
- [NTSB OAK66A0022](https://openairdocs.org/ntsb/OAK66A0022), Nov 10, 1965: Bell 47D1 (N68632), Bells Station, CA, substantial damage

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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