Pilot Debrief

Cessna 172 near Placerville, CA — 2019-03-31

Final reportWPR19LA102
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Date
2019-03-31
Location
Placerville, CA, USA
Airport
PVF
Aircraft
Cessna 172
Registration
N7033Q
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

Probable cause

The partial loss of engine power due to an improperly maintained carburetor.

NTSB narrative

During the climb after takeoff the engine lost partial power. The pilot performed troubleshooting steps and initiated a return to the airport. The airplane was not able to maintain altitude and landed in trees about 300 ft short of the approach end of the runway. Postaccident examination revealed sooting signatures on the spark plug electrodes and inner surfaces of the exhaust pipe, indicating an excessively rich fuel-to-air mixture. Examination of the carburetor revealed multiple maintenance-related discrepancies, including an incorrectly adjusted float and a loose carburetor bowl. The discrepancies likely resulted in mixture irregularities and a loss of engine power. Maintenance instructions and a series of service bulletins had been published by the carburetor manufacturer to address these issues. The discrepancies appeared to have been present for a while and were likely present at the time of the last annual inspection. The carburetor had not been overhauled or serviced in at least 19 years even though the manufacturer recommended overhaul at 10-year intervals.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have opted for a precautionary landing after engine roughness began.

NTSB coding

Evidence available

  • Video
  • Photos
  • 8 docket documents
View NTSB final reportView NTSB docket

Docket documents8

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