Pilot Debrief

5 RIVERS LLC SQ-2 near Soldotna, AK — 2022-07-27

Final reportANC22LA064
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Date
2022-07-27
Location
Soldotna, AK, USA
Aircraft
5 RIVERS LLC SQ-2
Registration
N58SQ
Category
Airplane
Highest injury
Serious
Fatalities
0
Phase of flight
Cruise

Probable cause

A total loss of engine power due to carburetor icing, which resulted from the pilot's failure to use carburetor heat while operating in conditions conducive to the formation of carburetor ice.

NTSB narrative

The pilot reported that, while in cruise flight at about 4,000 ft mean sea level (msl), he advanced the throttle to initiate a climb, but the engine began to lose power. In an effort to regain power, he further advanced the throttle and propeller levers and switched the fuel selector to the left tank to no avail. He subsequently made a forced landing in a small gully, which resulted in substantial damage to the wings and fuselage. When the pilot was asked if he applied carburetor heat after the loss of power, he stated that he did not, as there was no visible moisture in the area, and he thought carburetor ice would be unlikely. A postaccident examination revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. According to a carburetor icing probability chart, the ambient conditions present at the time of the accident were conducive to the development of serious icing at cruise power. It is likely that the loss of engine power was the result of the formation of carburetor icing, and had the pilot applied carburetor heat, engine power would likely have been restored.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot did not apply carburetor heat despite conditions indicating serious icing risk.

NTSB coding

Evidence available

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

Docket documents4

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