# NTSB CHI94LA023: Cessna 140, N73003, Frankenmuth, MI, October 24, 1993

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: October 24, 1993, 17:14 local (21:14 UTC)
- Place: Frankenmuth, MI
- Coordinates: 43.330699, -83.740051 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=43.3307&lon=-83.7401&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report September 7, 1994
- Report: Approved by Office Director
- NTSB case key (mKey): 9419
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA023
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9419/pdf
- Page: https://openairdocs.org/ntsb/CHI94LA023

## Probable cause

IMPROPER USE OF THE MIXTURE CONTROL BY THE PILOT.  FACTORS RELATED TO THE ACCIDENT WERE: THE SIMILARITY OF SHAPE, SIZE, AND COLOR OF THE MIXTURE AND CARBURETOR HEAT CONTROLS AND THE TERRAIN CONDITION (WITH CROP) IN THE EMERGENCY LANDING AREA.

## Sequence of events

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

- Loss of engine power, cruise
  - mixture - improper use of, pilot in command (cause)
  - acft/equip,inadequate control shape/size (contributing factor)
- Forced landing, descent - emergency
- In flight collision with terrain/water, landing
  - terrain condition - crop (contributing factor)

## Analysis

WHILE IN CRUISE FLIGHT, THE ENGINE SUSTAINED LOSS OF POWER. AN EMERGENCY LANDING WAS MADE IN A CROP FIELD, WHERE THE AIRPLANE WAS SUBSTANTIALLY DAMAGED.  THE PILOT INDICATED THAT HE MAY HAVE ACTIVATED THE MIXTURE INSTEAD OF THE CARBURETOR HEAT.  SUBSEQUENT EXAMINATION REVEALED THAT THE CONTROL KNOBS FOR THE MIXTURE AND CARBURETOR HEAT WERE THE SAME SHAPE, SIZE, AND COLOR.

## Factual narrative

On October 24, 1993, at 1714 eastern daylight time, a Cessna 140, N73003, registered to Ronald C. Thompson of Saginaw, Michigan, and operated by a private rated pilot, experienced a total loss of engine power while in cruise flight.  A forced landing was conducted to a crop field.  The airplane impacted the terrain on landing and sustained substantial damage.  The pilot and one passenger reported no injuries.  The personal 14 CFR Part 91 flight was operating in visual meteorological conditions.  No flight plan was on file.  The local flight departed Frankenmuth, Michigan at 1630.

On initial contact the pilot-in-command stated that he might have pulled the mixture instead of the carburetor heat.

An examination of the airplane subsequent to the accident did not find any mechanical anomalies which would have contributed to the accident; however the instrument panel arrangement of mixture and carburetor heat are non-standard according to modern industry accepted standards.  The shape, size, and color of the knobs is the same.  Verification of the function of the control is not identifiable by tactile or visual identification.

## Aircraft

- Registration: [N73003](https://openairdocs.org/aircraft/N73003), registered now, S/N 10208, built 1946 (OpenAirDocs)
- Reported make and model: CESSNA 140
- Registry model: [Cessna 140](https://openairdocs.org/model/cessna-140) (registry code 2071602) (OpenAirDocs)
- Registry engine: [Continental C85 series](https://openairdocs.org/engine/continental-c85-series) (registry code 17008, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 10208
- Engines: CONTINENTAL C-85-12 85 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Thompson, Ronald C.
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, July 8, 1993, 49 hours before
- Departed: 66G
- Destination: 78D, CARO, MI

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 43; private; airplane ratings: single-engine land; medical: class 3, valid medical--no waivers/lim.; seat: left; flight hours: 135 total, 17 in this make and model, 65 as pilot in command, 22 in the last 90 days, 6 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 15 statute miles
- Lowest ceiling: none
- Temperature: 68 °F, dew point 45 °F
- Altimeter: 29.00 inHg
- Observed at: MBS, 20 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 19931024040629A](https://openairdocs.org/incident/19931024040629A), Oct 24, 1993: Cessna 140, Frankenmuth, MI, Substantial damage. Lost power in cruise flight. Impacted in a crop field on forced landing. Mixture pulled instead carbueretor heat.

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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