Pilot Debrief

Stinson 108 near Keshena, WI — 2019-01-19

Final reportCEN19LA060
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Date
2019-01-19
Location
Keshena, WI, USA
Aircraft
Stinson 108
Registration
N97969
Category
Airplane
Highest injury
Serious
Fatalities
0
Phase of flight
Cruise

Probable cause

A total loss of engine power during cruise flight for undetermined reasons, which resulted in a forced landing and subsequent impact with trees.

NTSB narrative

The pilot was conducting a personal flight; while in cruise flight, the engine experienced a momentary and substantial loss of rpm. The pilot moved the mixture to the full-rich position, turned on the carburetor heat, and switched to the right fuel tank. The engine recovered power, and the pilot left the carburetor heat on for about 3 minutes and then slowly turned it off. About 2 minutes later, the engine lost all power. The pilot activated the starter, but it did not engage. The pilot chose to execute a forced landing on a road, during which the airplane impacted trees, bounced, and then came to rest inverted on a snow-covered embankment. Postaccident examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. The temperature and dewpoint at the time of the accident were not conducive for the formation of carburetor icing. The airplane had an adequate amount of fuel onboard at the time of the accident. Therefore, the reason for the loss of all engine power could not be determined.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have landed immediately after first loss of rpm.

NTSB coding

Evidence available

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

Docket documents5

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