# NTSB CHI90LA167: Cessna 150G, N4690X, Manchester, MI, July 3, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: July 3, 1990, 14:40 local (18:40 UTC)
- Place: Manchester, MI
- Coordinates: 42.13956, -84.030548 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=42.1396&lon=-84.0305&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report October 2, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 14700
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI90LA167
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14700/pdf
- Page: https://openairdocs.org/ntsb/CHI90LA167

## Probable cause

LOSS OF ENGINE POWER DUE TO A STUCK EXHAUST VALVE.

## Sequence of events

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

- Loss of engine power, cruise
  - engine assembly,valve,exhaust - seized (cause)
  - powerplant - failure,partial (contributing factor)
  - altitude - not possible, pilot in command (contributing factor)
  - emergency procedure - performed, pilot in command (contributing factor)
- Forced landing, descent - emergency
- Nose over, landing - roll
  - terrain condition - soft (contributing factor)

## Analysis

THE PILOT REPORTED THAT DURING NORMAL CRUISE FLIGHT HE NOTICED A 'SEVERE VIBRATION, AS WELL AS A TREMENDOUS LOSS OF POWER.' HE EXECUTED A FORCED LANDING IN A SOFT, RECENTLY PLOWED FIELD. WHEN THE NOSEWHEEL TOUCHED DOWN, THE AIRCRAFT NOSED OVER AND CAME TO A STOP UPSIDE DOWN. A POST-ACCIDENT INSPECTION OF THE ENGINE REVEALED NO COMPRESSION IN THE #2 CYLINDER. FURTHER EXAMINATION REVEALED THAT THE #2 CYLINDER EXHAUST VALVE WAS STUCK IN THE FULL OPEN POSITION. THE MOST RECENT MAINTENANCE WAS AN ANNUAL INSPECTION DATED FIVE MONTHS BEFORE THE ACCIDENT, AND THE AIRCRAFT/ENGINE HAD ACCUMULATED 83 HOURS SINCE THAT TIME. THE COMPRESSION CHECK WAS SATISFACTORY ON ALL CYLINDERS AT THE TIME OF THE ANNUAL INSPECTION.

## Aircraft

- Registration: [N4690X](https://openairdocs.org/deregistered/N4690X-2012-11-27), registration cancelled 2012-11-27, S/N 15064740, built 1966 (OpenAirDocs)
- Reported make and model: CESSNA 150G
- Registry model: [Cessna 150G](https://openairdocs.org/model/cessna-150g) (registry code 2071816) (OpenAirDocs)
- Registry engine: [Continental 0-200 series](https://openairdocs.org/engine/continental-0-200-series) (registry code 17020, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 15064740
- Airframe hours: 3013
- Engines: CONTINENTAL O-200-A 100 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Phn Air Services, Inc.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, February 10, 1990, 83 hours before
- Departed: PTK, PONTIAC, MI
- Destination: NONE, CLINTON, MI

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 35; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 129 total, 45 in this make and model, 81 as pilot in command, 38 in the last 90 days, 4 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 240° at 10 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 84 °F, dew point 68 °F
- Observed at: ARB

## 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 19900703023319A](https://openairdocs.org/incident/19900703023319A), Jul 3, 1990: Cessna 150G, Manchester, MI, Substantial damage. Engine quit en route. Nosed over landing in plowed field. Exhaust valve had stuck open.

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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