# NTSB CHI90FA233: Piper PA-23-160, N4231P, Odell, IL, August 16, 1990

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Field investigation · Final report
- Date: August 16, 1990, 14:42 local (19:42 UTC)
- Place: Odell, IL
- Coordinates: 40.999851, -88.520591 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=40.9999&lon=-88.5206&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 3 uninjured
- Status: Completed, report December 14, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 14546
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI90FA233
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14546/pdf
- Page: https://openairdocs.org/ntsb/CHI90FA233

## Probable cause

A LOSS OF LEFT ENGINE POWER DUE TO OIL ACCUMULATION IN THE RIGHT MAGNETO AND A NON-USABLE SPARK LEAD FROM THE LEFT MAGNETO. IN ADDITION, THE RIGHT ENGINE WAS UNABLE TO PROVIDE ADEQUATE POWER TO MAINTAIN ALTITUDE DUE TO A PARTIAL BLOCKAGE IN THE CARBURETOR BY A SECTION OF AIR INTAKE DUCT WHICH CAUSED THE ENGINE TO RUN RICH.

## 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
  - 1 engine
  - ignition system,magneto - contamination (cause)
  - ignition system,ignition lead - failure,partial (cause)
- Loss of engine power(partial) - nonmechanical, cruise - normal
  - 1 engine
  - fuel system,carburetor - blocked(partial) (cause)
- Forced landing, landing - flare/touchdown
- On ground/water encounter with terrain/water, landing - flare/touchdown
  - terrain condition - crop

## Analysis

DURING FLIGHT THE LEFT ENGINE BEGAN RUNNING ROUGH AND VIBRATING SEVERELY, AND IT WAS SHUT DOWN. THE PILOT WAS UNABLE TO MAINTAIN ALTITUDE ON THE RIGHT ENGINE AND A FORCED LANDING WAS MADE IN AN ALFALFA FIELD. EXAMINATION REVEALED THAT THE LEFT ENGINES RIGHT MAGNETO HAD AN ACCUMULATION OF OIL INSIDE ITS CASE. IN ADDITION, THE SPARK PLUG LEAD FROM THE LEFT MAGNETO FOR THE #1 CYLINDER WAS INTERNALLY DAMAGED. EXAMINATION OF THE RIGHT ENGINE REVEALED THAT THE INTAKE DUCT BETWEEN THE AIR FILTER AND THE CARBURETOR WAS DETERIORATED FROM EXPOSURE TO HOT EXHAUST PIPES. A 3' X 1/2' PIECE OF THE DUCT HAD SEPARATED AND WAS FOUND CAUGHT ON THE CARBURETOR VENTURI.

## Aircraft

- Registration: [N4231P](https://openairdocs.org/deregistered/N4231P-1990-12-17), registration cancelled 1990-12-17, S/N 231728 (OpenAirDocs)
- Reported make and model: PIPER PA-23-160
- Registry model: [Piper PA-23-160](https://openairdocs.org/model/piper-pa-23-160) (registry code 7102304) (OpenAirDocs)
- Category: Airplane
- Serial number: 1728
- Engines: LYCOMING O-320-B3B 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Joanne Bailey
- Departed: BMI, BLOOMINGTON, IL
- Destination: MDW, CHICAGO, IL
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 22; commercial, flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; flight hours: 560 total, 75 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 180° at 8 knots
- Visibility: 3 statute miles
- Lowest ceiling: 1,000 ft overcast
- Temperature: -0 °F, dew point -0 °F
- Observed at: BMI, 37 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 19900816033149A](https://openairdocs.org/incident/19900816033149A), Aug 16, 1990: Piper PA23160, Odell, IL, Substantial damage. Severe vibration left engine. Feathered. Limited right engine power. Force landed. Blocked air duct. Oil in magneto

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.