# NTSB ATL89FA163: Cessna 172F, N7939U, Vernon, AL, June 17, 1989

- Type: NTSB accident investigation
- Classification: Accident · Fatal · Field investigation · Final report
- Date: June 17, 1989, 17:30 local (22:30 UTC)
- Place: Vernon, AL
- Location: 33.7588° N, 88.1143° W: Placed by OpenAirDocs: center of Vernon, AL, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=33.7588&lon=-88.1143&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Fatal
- Injuries: 1 fatal
- Status: Completed, report June 22, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 7898
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL89FA163
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/7898/pdf
- Page: https://openairdocs.org/ntsb/ATL89FA163

## Probable cause

IMPROPER MAINTENANCE OF THE SPARK PLUGS BY THE PILOT/MECHANIC WHICH RESULTED IN A PARTIAL LOSS OF ENGINE POWER, AND THE PILOT'S FAILURE TO CLEAR TREES DURING AN EMERGENCY LANDING IN AN OPEN FIELD RESULTING IN AN INADVERTENT STALL.

## Sequence of events

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

- Loss of engine power(partial) - mech failure/malf, cruise
  - fluid,fuel grade - improper
  - ignition system,spark plug - overtemperature (cause)
  - maintenance - inadequate, pilot in command (cause)
  - ignition system,spark plug - failure,total (cause)
  - engine assembly,valve,exhaust - movement restricted (cause)
  - engine assembly,cylinder - low compression (cause)
- Forced landing, approach - vfr pattern - final approach
- In flight collision with terrain/water, approach - vfr pattern - final approach
  - terrain condition - high obstruction(s) (contributing factor)
  - clearance - misjudged, pilot in command (cause)
  - stall - inadvertent, pilot in command

## Aircraft

- Registration: [N7939U](https://openairdocs.org/deregistered/N7939U-2014-11-19), registration cancelled 2014-11-19, S/N 17251939, built 1964 (OpenAirDocs)
- Reported make and model: CESSNA 172F
- Registry model: [Cessna 172F](https://openairdocs.org/model/cessna-172f) (registry code 2072414) (OpenAirDocs)
- Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17251939
- Airframe hours: 2209
- Engines: CONTINENTAL O-300-D 145 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Robinson, Hurskin  C.
- Airworthiness certificate: Standard, Utility; Standard, Normal
- Last inspection: Annual, November 3, 1983, 44 hours before
- Departed: M55, VERNON, AL

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 64; private; airplane ratings: single-engine land; medical: expired; seat: left; toxicology performed; flight hours: 236 total

## Weather

- Conditions: Visual (VMC), Day
- Wind: 200° at 4 knots
- Visibility: 9 statute miles
- Lowest ceiling: 25,000 ft overcast
- Temperature: 84 °F, dew point 61 °F
- Altimeter: 30.00 inHg
- Observed at: CBM, 19 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 19890617015959A](https://openairdocs.org/incident/19890617015959A), Jun 17, 1989: Cessna 172F, Vernon, AL, Substantial damage, 1 fatal. Engine lost power,struck tree tips edge of open field. Crashed inverted. Spark plug core 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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