# NTSB CHI92LA003: Cessna 150M, N704CW, Marion, WI, October 8, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 8, 1991, 12:20 local (17:20 UTC)
- Place: Marion, WI
- Coordinates: 44.6697, -88.879287 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=44.6697&lon=-88.8793&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report December 14, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 15329
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI92LA003
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/15329/pdf
- Page: https://openairdocs.org/ntsb/CHI92LA003

## Probable cause

THE FAILURE OF THE EXHAUST AND INTAKE VALVES.  FACTORS CONTRIBUTING TO THE ACCIDENT WERE DOWNHILL TERRAIN AND A COLLAPSED NOSEGEAR.

## 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 - normal
  - engine assembly,valve,exhaust - failure,total (cause)
  - remedial action - performed, pilot in command
  - engine assembly,valve,intake - failure,total (cause)
  - engine assembly,piston - failure,partial
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - grass
  - terrain condition - downhill (contributing factor)
  - landing gear,nose gear - collapsed (contributing factor)

## Analysis

THE STUDENT PILOT WAS FLYING A SINGLE ENGINE AIRPLANE ON A SOLO CROSS COUNTRY FLIGHT WHEN THE ENGINE BEGAN TO RUN ROUGH.  THE ENGINE LOST APPROXIMATELY 25 PERCENT OF THE ORIGINAL POWER SETTING.  THE AIRPLANE WOULD NOT MAINTAIN ALTITUDE AND WAS, ACCORDING TO THE PILOT, 'VIBRATING VERY BADLY.'  THE PILOT CHOSE A FIELD WHICH HE BELIEVED SMOOTH AND LEVEL. UPON TOUCHDOWN THE AIRPLANE ROLLED DOWN HILL AND NOSED OVER AT THE BOTTOM OF THE HILL AFTER ITS NOSEGEAR COLLAPSED.  INSPECTION OF THE ENGINE REVEALED FAILED INTAKE AND EXHAUST VALVES, AND A PISTON WITH HOLES IN ITS TOP. THE AIRPLANE WAS OPERATING UNDER AND AUTO GAS STC WHICH ALLOWED THE USE OF THAT FUEL AND ANY MIXTURE COMBINATION OF 100 LL AVIATION FUEL.

## Aircraft

- Registration: [N704CW](https://openairdocs.org/deregistered/N704CW-1994-03-16), registration cancelled 1994-03-16, S/N 15078515 (OpenAirDocs)
- Reported make and model: CESSNA 150M
- Registry model: [Cessna 150M](https://openairdocs.org/model/cessna-150m) (registry code 2071830) (OpenAirDocs)
- Category: Airplane
- Serial number: 15078515
- Engines: Continental O-200 A 100 horsepower reciprocating
- Damage: Substantial damage
- Flight: Instructional, Part 91
- Operator: James H. Jahnke
- Registered owner: James H. Jahnke
- Destination: 92G, PULASKI, WI
- Flight plan: VFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 37; student; medical: class 3, valid medical--w/ waivers/lim; flight hours: 41 total, 41 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 220° at 13 knots
- Visibility: 10 statute miles
- Lowest ceiling: 1,700 ft broken
- Temperature: -0 °F, dew point -0 °F
- Observed at: GRB, 30 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 19911008045479A](https://openairdocs.org/incident/19911008045479A), Oct 8, 1991: Cessna 150M, Marion, WI, Substantial damage. Lost partial power and rough engine,elected land in field. Rolled down hill,nosed over. Valves made hole in piston.

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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