# NTSB CHI94LA005: Cessna 150G, N4646X, Osceola, MO, October 3, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 3, 1993, 12:30 local (17:30 UTC)
- Place: Osceola, MO
- Coordinates: 38.039615, -93.690826 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.0396&lon=-93.6908&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed, report September 7, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 9405
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA005
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9405/pdf
- Page: https://openairdocs.org/ntsb/CHI94LA005

## Probable cause

FRACTURE OF THE NUMBER FOUR PISTON AT THE PISTON PIN BOSS. A FACTOR RELATED TO THE ACCIDENT WAS: THE LACK OF SUITABLE TERRAIN FOR AN EMERGENCY LANDING.

## 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,piston - fractured (cause)
- Forced landing, descent - emergency
- Ditching, landing
  - terrain condition - none suitable (contributing factor)
  - terrain condition - water

## Analysis

DURING CRUISE, THERE WAS A COMPLETE LOSS OF ENGINE POWER, AND THE PILOT WAS FORCED TO DITCH THE AIRPLANE INTO A NEARBY LAKE.  AN EXAMINATION OF THE ENGINE REVEALED THAT THE #4 PISTON HAD FRACTURED AT THE PISTON BOSS, AND THE #4 CYLINDER HAD FRACTURED ABOVE THE COOLING FINS AT THE CYLINDER HEAD.

## Factual narrative

On October 3,1993, about 1230 central daylight time, a Cessna 150G airplane, N4646X, experienced loss of engine power during cruise and ditched in Truman Reservoir near Osceola, Missouri.  The solo private pilot reported no injury.  The airplane was substantially damaged.  Visual meteorological conditions existed in the vicinity.  The personal flight originated in Belton, Missouri about 1145 without a flight plan and operated under 14 CFR 91.

The pilot stated the engine made a bang, shook and ran roughly about 5 miles from destination.  As he checked indicators, the engine quit running.  The airplane glided to water touchdown about 60 yards offshore.  The pilot exited the submerged cabin and swam to shore.

External examination of the engine showed the number four cylinder fractured above the cooling fins at its cylinder head.  Internally, the number four cylinder head was found fractured at the piston pin boss.

## Aircraft

- Registration: [N4646X](https://openairdocs.org/deregistered/N4646X-1996-05-14), registration cancelled 1996-05-14, S/N 15064696 (OpenAirDocs)
- Reported make and model: CESSNA 150G
- Registry model: [Cessna 150G](https://openairdocs.org/model/cessna-150g) (registry code 2071816) (OpenAirDocs)
- Category: Airplane
- Serial number: 15064696
- Engines: CONTINENTAL O-200-A 100 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Zaner Aviation
- Airworthiness certificate: Standard, Utility
- Last inspection: Annual, February 3, 1993, 84 hours before
- Departed: MO24
- Destination: MO24
- Airport: MO24, Osceola Municipal

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; private; airplane ratings: single-engine land; medical: class 3, valid medical--w/ waivers/lim; seat: left; flight hours: 986 total, 944 in this make and model, 894 as pilot in command, 76 in the last 90 days, 46 in the last 30 days, 36 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 230° at 12 knots
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 64 °F
- Altimeter: 30.00 inHg
- Observed at: SGF, 60 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 19931003037379A](https://openairdocs.org/incident/19931003037379A), Oct 3, 1993: Cessna 150G, Osceola, MO, Substantial damage. Engine made loud bang and quit near airport. Ditched in lake. Cylinder had fractured at piston pin boss.

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.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.