Pilot Debrief

CESSNA U206G near Iliamna, AK — 2010-06-30

Final reportANC10LA056
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Date
2010-06-30
Location
Iliamna, AK, USA
Aircraft
CESSNA U206G
Registration
N4596U
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Cruise

Probable cause

The total loss of engine power during cruise flight due to a fractured crankshaft.

NTSB narrative

The float-equipped airplane was in cruise flight on a sightseeing flight when there was a total loss of engine power. After several unsuccessful attempts to restart the engine, the pilot made a forced landing on tundra-covered terrain, and the airplane nosed over. Postaccident disassembly of the engine found that the crankshaft had fractured at the No. 2 journal. Laboratory examination of the crankshaft found "ladder cracking" associated with the journal fracture, which is consistent with a reduced oil flow and overheating of the surface area. At the time of the accident, the engine had 441 hours of operation since major overhaul, which was performed on October 21, 2008.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have monitored engine performance more closely after EGT rise.

NTSB coding

Evidence available

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

Docket documents5

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