# NTSB ATL90LA151: Cessna 172B, N8091X, Midway, TN, July 29, 1990

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: July 29, 1990, 14:30 local (18:30 UTC)
- Place: Midway, TN
- Coordinates: 36.160549, -83.039756 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.1605&lon=-83.0398&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor, 3 uninjured
- Status: Completed, report September 10, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 8259
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL90LA151
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/8259/pdf
- Page: https://openairdocs.org/ntsb/ATL90LA151

## Probable cause

TOTAL FAILURE OF THE NUMBER FOUR EXHAUST VALVE, RESULTING IN ENGINE POWER LOSS AND THE SUBSEQUENT FORCED LANDING OF THE AIRPLANE.

## 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 - normal
  - engine assembly,valve,exhaust - failure,total (cause)
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - ditch

## Analysis

THE PILOT WAS 20 MINUTES INTO THE FLIGHT WHEN HE NOTED THAT THE ENGINE WAS MAKING A BINDING NOISE AND SEEMED TO BE IN A SLIGHT STRAIN. WHILE RETURNING TO THE AIRPORT, THE ENGINE BEGAN TO LOSE POWER AND THE PILOT COULD NO LONGER MAINTAIN ALTITUDE. THE AIRPLANE WAS FORCE LANDED IN A CORNFIELD AND WAS SUBSTANTIALLY DAMAGED WHEN IT CONTACTED A DITCH AND NOSED OVER. EXAMINATION OF THE ENGINE REVEALED THAT THE NUMBER FOUR CYLINDER EXHAUST VALVE HAD FAILED, ENTERING THE CYLINDER. THE LOOSE VALVE DAMAGED AND SEIZED THE PISTON, BREAKING THE CONNECTING ROD. THE VALVES WERE LAST REPLACED DURING A MAJOR OVERHAUL IN 1971. ABOUT 681 HOURS HAD BEEN LOGGED SINCE THE OVERHAUL.

## Aircraft

- Registration: [N8091X](https://openairdocs.org/deregistered/N8091X-1992-02-20), registration cancelled 1992-02-20, S/N 17248591 (OpenAirDocs)
- Reported make and model: CESSNA 172B
- Registry model: [Cessna 172B](https://openairdocs.org/model/cessna-172b) (registry code 2072406) (OpenAirDocs)
- Category: Airplane
- Serial number: 17248591
- Airframe hours: 1834
- Engines: CONTINENTAL O-300-D 145 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Carl E. Burke
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, February 8, 1990, 52 hours before
- Departed: GCY, GREENEVILLE, TN
- Destination: 3A2, TAZEWELL, TN

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 160 total, 100 in this make and model, 10 in the last 90 days, 2 in the last 30 days

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 6 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 88 °F, dew point 64 °F
- Altimeter: 30.00 inHg
- Observed at: TRI, 34 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 19900729029069A](https://openairdocs.org/incident/19900729029069A), Jul 29, 1990: Cessna 172B, Midway, TN, Substantial damage. Engine ingested a broken valve which jammed piston and broke a connecting rod. Nosed over landing in a cornfield.

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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