# NTSB MKC86LA078: Cessna 172, N80751, Ava, MO, April 2, 1986

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: April 2, 1986, 17:25 local (23:25 UTC)
- Place: Ava, MO
- Coordinates: 36.950111, -92.660896 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.9501&lon=-92.6609&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 34153
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MKC86LA078
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/34153/pdf
- Page: https://openairdocs.org/ntsb/MKC86LA078

## 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,intake - failure,total (cause)
  - engine assembly,valve,intake - fatigue
  - precautionary landing - initiated, pilot in command
- Forced landing, descent - emergency
- On ground/water collision with object, landing - roll
  - object - tree(s)

## Analysis

THE PLT REPORTS THAT THE ENG BEGAN TO RUN ROUGH AND LOSE RPM WHILE THE ACFT WAS CRUISING AT 2500 FT. HE SAID HE ATTEMPTED EMERG PROC BUT THE LOSS OF RPM CONTINUED AND HE DECIDED ON AN OFF-ARPT LANDING. DURING THE APCH TO THE LANDING AREA THE ENG RPM DROPPED TO 1200 AND THE PLT SECURED THE ENG. DURING THE FORCED LANDING THE ACFT HIT A SMALL TREE AND A FENCE POST. EXAM OF THE ENG REVEALED A BROKEN EXHAUST VALVE IN THE #1 CYL. METALLURGICAL EXAM OF THE BROKEN VALVE REVEALED EVIDENCE OF A PROGRESSIVE FAILURE.

## Aircraft

- Registration: [N80751](https://openairdocs.org/aircraft/N80751), registered now, S/N 17266728, built 1976 (OpenAirDocs)
- Reported make and model: CESSNA 172
- Registry model: [Cessna 172M](https://openairdocs.org/model/cessna-172m) (registry code 2072418) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 17266728
- Airframe hours: 5950
- Engines: LYCOMING O-320-E2D 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: School Of The Ozarks
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, January 22, 1986, 94 hours before
- Departed: PLK, POINT LOOKOUT, MO
- Destination: 73K, AVA, MO

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 18; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 191 total, 114 in this make and model, 131 as pilot in command, 69 in the last 90 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 10 knots
- Visibility: 15 statute miles
- Lowest ceiling: 4,000 ft broken
- Temperature: 70 °F
- Altimeter: 30.00 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 19860402052829A](https://openairdocs.org/incident/19860402052829A), Apr 2, 1986: Cessna 172M, Ava, MO, Substantial damage. Engine ran rough and lost power en route. Struck a tree and fence post on forced landing. Broken exhaust valve.

## Other investigations on N80751 (1)

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.

- [NTSB MKC82DA118](https://openairdocs.org/ntsb/MKC82DA118), Jul 6, 1982: Cessna 172 (N80751), Point Lookout, MO, substantial damage

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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