Pilot Debrief

CESSNA 170B near Big Lake, AK — 2020-09-23

Final reportANC20LA099
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Date
2020-09-23
Location
Big Lake, AK, USA
Aircraft
CESSNA 170B
Registration
N4380B
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Approach

Probable cause

The pilot’s failure to utilize carburetor heat while flying in conditions conducive to carburetor icing, which resulted in a total loss of engine power.

NTSB narrative

During a landing to a remote off-airport gravel bar located along a river, while at about 20 ft above ground level, the airplane’s engine lost power. The engine then surged briefly before a total loss of engine power occurred. Subsequently, the airplane landed short of the gravel bar in the river and the airplane nosed over. The airplane sustained substantial damage to the left wing and empennage. A postaccident examination revealed no mechanical failures or malfunctions. A postaccident engine run was successfully performed. A non-aviation fuel tank was installed on the top of the fuselage to provide a fuel source. Air was applied to the fuel lines to provide pressure to ensure proper fuel flow, no contaminates were noted in the fuel lines. The temperature and dew point were entered into a carburetor icing probability chart, which coincided with the “serious icing in glide power” category.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted landing when engine began to sputter.

NTSB coding

Evidence available

  • Photos
  • 6 docket documents
View NTSB final reportView NTSB docket

Docket documents6

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