# NTSB FTW89DRD14: Grumman G-164A, N7498, Franklin, LA, September 8, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Final report
- Date: September 8, 1989, 16:00 local (21:00 UTC)
- Place: Franklin, LA
- Coordinates: 29.799325, -91.509666 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=29.7993&lon=-91.5097&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report September 5, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 22735
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW89DRD14
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/22735/pdf
- Page: https://openairdocs.org/ntsb/FTW89DRD14

## Probable cause

FATIGUE FAILURE OF THE PROPELLER BLADE, WHICH RESULTED IN SEPARATION OF THE BLADE'S TIP AND SEVERE ENGINE VIBRATION.  THE SOFT TERRAIN WAS A RELATED FACTOR.

## Sequence of events

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

- Airframe/component/system failure/malfunction, maneuvering
  - propeller system/accessories,blade - fatigue (cause)
  - propeller system/accessories,blade - separation
  - powerplant - vibration
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - soft (contributing factor)

## Analysis

THE AG PILOT HAD JUST FINISHED SPRAYING A LOAD OF CHEMICALS & WAS IN A TURN TO LOOK AT THE NEXT FIELD TO BE SPRAYED, WHEN THE AIRPLANE STARTED TO VIBRATE VIOLENTLY. HE REDUCED POWER & TURNED TO LINE UP WITH A TURNROW FOR A FORCED LANDING. AFTER TOUCHDOWN, THE ACFT ROLLED ABOUT 300 YARDS ON SOFT TERRAIN, THEN NOSED OVER AS THE PLT APPLIED BRAKES TO AVOID A DITCH. A INVESTIGATION REVEALED THAT 13 INCHES OF ONE PROPELLER BLADE WAS MISSING. A EXAM OF THE FRACTURE SURFACE SHOWED INDICATIONS OF A PRE-EXISTING CRACK ON THE LEADING EDGE OF THE BLADE.

## Aircraft

- Registration: [N7498](https://openairdocs.org/deregistered/N7498-1993-10-20), registration cancelled 1993-10-20, S/N 945 (OpenAirDocs)
- Reported make and model: GRUMMAN G-164A
- Registry model: [Grumman Acft ENG Cor-Schweizer G-164A](https://openairdocs.org/model/grumman-acft-eng-cor-schweizer-g-164a) (registry code 3952801) (OpenAirDocs)
- Category: Airplane
- Serial number: 945
- Airframe hours: 6833
- Engines: P&W R-1340-AN-1 600 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Terry Flying Service
- Registered owner: Terry Flying Service Inc
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: Annual, July 2, 1989, 328 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 5,034 total, 328 in this make and model, 5,034 as pilot in command, 375 in the last 90 days, 40 in the last 30 days, 8 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 9 statute miles
- Lowest ceiling: none
- Temperature: 91 °F
- Altimeter: 29.00 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 19890908034299A](https://openairdocs.org/incident/19890908034299A), Sep 8, 1989: Scwzer G164A, Franklin, LA, Substantial damage. Severe engine vibration at cruise. Flipped over in a field braking to avoid a canal. Prop blade broke from fatigue.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.