# NTSB ATL83FKQ03: Air Tractor AT-301, N8511S, Redwood, MS, August 25, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: August 25, 1983, 10:00 local (15:00 UTC)
- Place: Redwood, MS
- Coordinates: 32.500602, -90.789619 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=32.5006&lon=-90.7896&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 5975
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL83FKQ03
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/5975/pdf
- Page: https://openairdocs.org/ntsb/ATL83FKQ03

## 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
  - propeller system/accessories,counterweight - failure,total (cause)
  - maintenance,inspection - poor, other maintenance personnel (cause)
  - maintenance,lubrication - poor, other maintenance personnel (cause)
- Forced landing, landing - flare/touchdown

## Analysis

THE ACFT MADE A FORCED LANDING IN A SOYBEAN FIELD AFTER SEVERE VIBRATION DEVELOPED DURING A SPRAYING OPERATION. THE PILOT STATED THAT THE POWERPLANT AND FLT CONTROLS WERE FUNCTIONING NORMALLY AT THE TIME OF THE ACCIDENT. AN ON-SCENE INVESTIGATION REVEALED THAT THE COUNTERWEIGHT BEARING SHAFT (P/N 63546) BROKE ALLOWING THE PROPELLER BLADE TO GO TO HIGHER PITCH WHILE THE OTHER BLADE REMAINED AT CRUISE PITCH SETTING. EXAMINATION OF BOTH PROPELLER BLADE COUNTERWEIGHTS REVEALED THAT THE INTERNAL PARTS HAD MINIMUM AMOUNT OF LUBRICATION. THE SHAFT THAT BROKE WAS ALSO RUSTY AND THE INNER BEARING RACE WAS BROKEN WITH 5 BALL BEARING MISSING. THERE WERE OTHER MAINTENANCE DICREPANCIES ON THIS SHAFT ASSEMBLY. THE TOTAL TIME OF THIS HAMILTON STANDARD 12D40 PROPELLER IS UNKNOWN. THE TIME SINCE THE ACFT WAS INSPECTED IS 194 HOURS.

## Aircraft

- Registration: [N8511S](https://openairdocs.org/aircraft/N8511S), registered now, S/N 301-0134, built 1978 (OpenAirDocs)
- Reported make and model: AIR TRACTOR AT-301
- Registry model: [Air Tractor AT-301](https://openairdocs.org/model/air-tractor-at-301) (registry code 0390103) (OpenAirDocs)
- Registry engine: [Pratt & Whitney R1340 series](https://openairdocs.org/engine/pratt-whitney-r1340-series) (registry code 52016, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 301-0134
- Airframe hours: 2574
- Engines: P&W R-1340-AN1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Martin L. Hallman
- Registered owner: Layman G. Sneed
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, May 9, 1983, 194 hours before
- Departed: SNE, REDWOOD, MS

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 49; commercial; airplane ratings: multi-engine land, single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: front; flight hours: 17,931 total, 2,049 in this make and model, 17,931 as pilot in command, 150 in the last 90 days, 70 in the last 30 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 8 statute miles
- Lowest ceiling: none
- Temperature: 99 °F
- Altimeter: 30.00 inHg

## 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 19830825043939A](https://openairdocs.org/incident/19830825043939A), Aug 25, 1983: Airtrc AT301, Redwood, MS, Substantial damage. Crash occurred during emergency landing after severe vibration caused by prop counterweight bearing shaft breaking

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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