# NTSB ATL90LA172: Cessna 172RG, N6411V, Ozark, AL, September 17, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: September 17, 1990, 13:45 local (18:45 UTC)
- Place: Ozark, AL
- Location: 31.4591° N, 85.6405° W: Placed by OpenAirDocs: center of Ozark, AL, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=31.4591&lon=-85.6405&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report March 12, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 8275
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL90LA172
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8275/pdf
- Page: https://openairdocs.org/ntsb/ATL90LA172

## Probable cause

INADEQUATE ENGINE OVERHAUL PROCEDURES WHICH ALLOWED THE INSTALLATION OF THE ENGINE PLUG WITHOUT SAFETY WIRE TO HOLD IT IN PLACE, AND WHICH RESULTED IN OIL STARVATION OF THE ENGINE.

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise
  - fluid,oil - starvation (cause)
  - maintenance,overhaul - inadequate, other maintenance personnel (cause)
- Forced landing, descent - emergency
- Nose gear collapsed, landing - roll

## Analysis

THE INSTRUCTOR REPORTED THAT AFTER LEVELING AT CRUISE ALTITUDE A BURNING ODOR WAS DETECTED. A FORCED LANDING TO A HAYFIELD WAS BEGUN. DURING THE DESCENT OIL COVERED THE WINDSCREEN & THE ENGINE SEIZED. WHILE ON LANDING ROLL THE NOSE LANDING GEAR SHEARED. SUBSEQUENT EXAM OF THE ENGINE REVEALED THAT A PLUG WHICH HAD BEEN INSERTED IN ONE OF THE VACANT ENGINE COMPONENT DRIVE GEAR OPENINGS HAD NOT BEEN SAFETY WIRED. THE PLUG WAS FOUND IN THE BOTTOM OF THE ENGINE COWLING. THE ENGINE OIL HAD DRAINED OUT OF THE DRIVE OPENING WHEN THE PLUG FELL OUT WHICH RESULTED IN SEIZURE OF THE ENGINE.

## Aircraft

- Registration: [N6411V](https://openairdocs.org/aircraft/N6411V), registered now, S/N 172RG0673, built 1980 (OpenAirDocs)
- Reported make and model: CESSNA 172RG
- Registry model: [Cessna 172RG](https://openairdocs.org/model/cessna-172rg) (registry code 2072438) (OpenAirDocs)
- Registry engine: [Lycoming O&VO-360 series](https://openairdocs.org/engine/lycoming-o-vo-360-series) (registry code 41514, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 172RG0673
- Engines: LYCOMING O-360F1A6 180 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: Alabama Aviation & Tech Coll
- Last inspection: Annual, August 21, 1990, 0 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 32; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; flight hours: 722 total, 87 in this make and model, 717 as pilot in command, 346 in the last 90 days, 91 in the last 30 days, 3 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 45° at 5 knots, gusting 10
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 90 °F, dew point -0 °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 19900917039599A](https://openairdocs.org/incident/19900917039599A), Sep 17, 1990: Cessna 172RG, Ozark, AL, Substantial damage. Smoke from engine,lost oil pressure,engine seized. Nosed up landing. Brass plug in governor gear drive hole missing

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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