# NTSB LAX92LA097: Cessna 120, N3010N, Sonoma, CA, January 21, 1992

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Limited investigation · Final report
- Date: January 20, 1992, 16:02 local (Jan 21, 1992, 00:02 UTC)
- Place: Sonoma, CA
- Coordinates: 38.240699, -122.4598 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=38.2407&lon=-122.4598&mi=10
- Phase of flight: [Initial climb](https://openairdocs.org/ntsb-phases/350) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report August 13, 1993
- Report: Approved by Office Director
- NTSB case key (mKey): 27540
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX92LA097
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/27540/pdf
- Page: https://openairdocs.org/ntsb/LAX92LA097

## Probable cause

ENGINE FAILURE DUE TO A BINDING MIXTURE CONTROL SHAFT.  THE BINDING MIXTURE CONTROL SHAFT WAS THE RESULT OF INADEQUATE MAINTENANCE WHICH ALLOWED THE ACCUMULATION OF MOISTURE AND WATER IN THE CARBURETOR TO REMAIN FOR AN EXTENDED PERIOD OF TIME CAUSING RUST AND CORROSION.  A FACTOR IN THE ACCIDENT WAS THE UNSUITABLE NATURE OF THE TERRAIN FOR THE FORCED LANDING ATTEMPT.

## Sequence of events

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

- Loss of engine power(total) - nonmechanical, takeoff - initial climb
  - fuel system,carburetor - contamination (cause)
  - mixture control - jammed (cause)
  - fuel system - not maintained, other maintenance personnel (cause)
  - powerplant controls - not maintained, other maintenance personnel (cause)
- Forced landing, descent - emergency
  - terrain condition - none suitable (contributing factor)
- On ground/water encounter with terrain/water, landing - roll
  - terrain condition - rough/uneven
  - terrain condition - ditch

## Analysis

THE PILOT AND PASSENGER DEPARTED FOR A LOCAL FLIGHT TO PRACTICE LANDINGS. AT ABOUT 200 TO 300 FEET AGL ON THE CROSSWIND LEG, THE ENGINE QUIT. AN ATTEMPT TO RESTART THE ENGINE FAILED AND THE PILOT LANDED THE AIRCRAFT IN A PASTURE WHICH WAS SLOPED, ROUGH AND HAD A DRY CREEK BED IN IT. UPON REACHING THE CREEK BED, THE AIRPLANE NOSED OVER. EXAMINATION OF THE AIRCRAFT REVEALED THAT THE CARBURETOR MIXTURE CONTROL LINKAGE WAS FROZEN AND WOULD NOT RESPOND TO MOVEMENT OF THE COCKPIT CONTROL. DISASSEMBLY OF THE CARBURETOR REVEALED EVIDENCE OF MOISTURE AND WATER CONTAMINATION, ACCUMULATED OVER AN EXTENDED PERIOD OF TIME, WHICH CAUSED RUST, CORROSION AND BINDING OF THE MIXTURE CONTROL SHAFT IN THE LEAN TO NEAR IDLE CUTOFF POSITION. EXAMINATION OF THE ENGINE RECORDS REVEALED THAT THE LAST TIME THE CARBURETOR WAS OVERHAULED WAS ABOUT JUNE 2, 1983, WHILE INSTALLED IN AN EXPERIMENTAL AIRCRAFT. THE ENGINE WAS INSTALLED IN THE ACCIDENT AIRCRAFT ON MAY 17, 1991, AFTER ACCUMULATING ABOUT 132 HOURS IN ABOUT 8 YEARS AND 6 MONTHS. THE MANUFACTURER RECOMMENDS THAT THE CARBURETOR BE OVERHAULED EVERY 5 CALENDER YEARS.

## Aircraft

- Registration: [N3010N](https://openairdocs.org/deregistered/N3010N-1995-03-09), registration cancelled 1995-03-09, S/N 13268 (OpenAirDocs)
- Reported make and model: CESSNA 120
- Registry model: [Cessna 120](https://openairdocs.org/model/cessna-120) (registry code 2071402) (OpenAirDocs)
- Category: Airplane
- Serial number: 13268
- Airframe hours: 7777
- Engines: CONTINENTAL C-90-12F 90 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Operator: Andrew J. Bowe, Jr
- Registered owner: Andrew J. Bowe, Sr
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, May 17, 1991, 71 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 18; flight instructor, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: left; flight hours: 442 total, 18 in this make and model, 363 as pilot in command, 72 in the last 90 days, 14 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 120° at 4 knots
- Visibility: 7 statute miles
- Lowest ceiling: 5,000 ft overcast
- Temperature: 50 °F
- Altimeter: 30.00 inHg

## 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 19920120000739A](https://openairdocs.org/incident/19920120000739A), Jan 20, 1992: Cessna 120, Sonoma, CA, Substantial damage. Engine quit on climbout. Nosed over in dry creek bed landing. Mixture control shaft seized lean. 138 hrs in 8 years

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.