Pilot Debrief

STINSON 108-3 near Beaumont, TX — 2013-05-23

Final reportCEN13LA305
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Date
2013-05-23
Location
Beaumont, TX, USA
Airport
BMT
Aircraft
STINSON 108-3
Registration
N121CM
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Initial climb

Probable cause

The lack of a forward clamp on the carburetor heat box rubber boot, which allowed the boot to be ingested into the inlet of the carburetor heat box, restricting the airflow and leading to a subsequent partial loss of engine power.

NTSB narrative

The pilot reported that the airplane's engine lost partial power shortly after takeoff. The airplane was unable to maintain altitude, so he executed a forced landing to a field, and the airplane nosed over. Postaccident examination revealed that the rubber boot between the carburetor heat box and cowl was missing its forward clamp, which was not found in the wreckage The clamp was likely missing because an improper clamp was used or a clamp was not installed properly, which allowed the boot to come loose and to be ingested into the inlet of the carburetor heat box, restricting the airflow and resulting in a rich fuel mixture and the subsequent partial loss of engine power. No other anomalies were found with the engine or its systems.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Install proper clamp on carburetor heat box boot to prevent airflow restriction.

NTSB coding

Evidence available

  • 3 docket documents
View NTSB final reportView NTSB docket

Docket documents3

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