# NTSB FTW83LA351: Grumman G-164A, N4866, Chilton, TX, July 25, 1983

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 25, 1983, 08:30 local (13:30 UTC)
- Place: Chilton, TX
- Coordinates: 31.300275, -97.059898 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=31.3003&lon=-97.0599&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
- ADs cited in the narratives: AD 82-23-04, AD 83-15-06 (OpenAirDocs)
- NTSB case key (mKey): 20990
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW83LA351
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/20990/pdf
- Page: https://openairdocs.org/ntsb/FTW83LA351

## 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
  - engine assembly,crankshaft - worn (cause)
  - engine assembly,crankshaft - vibration (cause)
  - propeller system/accessories,hub - separation (cause)
- Forced landing, landing - flare/touchdown
- Main gear collapsed, landing - flare/touchdown
  - landing gear,main gear - overload
- On ground/water collision with object, landing - roll
  - object - fence (contributing factor)

## Analysis

DURING THE 1ST SWATH RUN THE PROP SEPARATED FROM THE ENG. A FORCED LANDING WAS MADE IN A PLOWED FIELD SHEARING ONE MAIN LANDING GEAR. THE ACFT THEN WENT THROUGH A BARBED WIRE FENCE. THE #4 CYLINDER WAS REMOVED TO INSPECT THE VIBRATION DAMPER PINS IN ACCORDANCE WITH AD 82-23-04. THE TRAILING PIN ON THE REAR VIBRATION DAMPER EVIDENCED CONSIDERABLE WEAR. THE WEAR HAD PROGRESSED TO THE POINT THAT THE DAMPER HAD BEEN DISPLACED FROM ITS NORMAL POSITION TO A POINT CAUSING INTERFERENCE WITH THE SKIRTS OF THE #2 & #3 PISTONS. THIS WEAR, IN ADDITION WITH MINOR WEAR TO THE LEADING PIN, CAUSED VIBRATION & SUBSEQUENT PROP SEPARATION. TWO DAYS AFTER THE ACCIDENT, AD 83-15-06 WAS ISSUED GROUNDING ALL ACFT WITH THE PROP-ENG COMBINATION THAT WAS INSTALLED ON THIS ACFT.

## Aircraft

- Registration: N4866 (not matched to a registry record)
- Reported make and model: GRUMMAN G-164A
- Category: Airplane
- Serial number: 1019
- Engines: PZL-Rzeszow PZL-3S 630 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: Harman Air Service Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, March 25, 1983, 30 hours before
- Departed: T15, MARLIN, TX

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: front; flight hours: 5,850 total, 2,285 in this make and model, 5,300 as pilot in command, 85 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 3 knots, gusting 5
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 81 °F

## 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 19830725035579A](https://openairdocs.org/incident/19830725035579A), Jul 25, 1983: Scwzer G164A, Marlin, TX, Substantial damage. Engine vibrated then the prop assembly departed the aircraft. Crankshaft vibration damper caught on piston skirts.

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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