Pilot Debrief

CESSNA 207 near Bethel, AK — 2013-03-06

Final reportANC13LA029
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Date
2013-03-06
Location
Bethel, AK, USA
Aircraft
CESSNA 207
Registration
N1704U
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Climb

Probable cause

The failure of the engine’s No. 1 piston connecting rod retaining bolts due to fatigue fracturing, which resulted in a loss of engine power during cruise flight.

NTSB narrative

Shortly after departure on the commercial passenger/cargo flight, the airplane's engine lost power. The pilot conducted a forced landing on a snow-covered, sparsely treed, tundra area. Just before touchdown, the left stabilizer struck treetops, and the airplane sustained substantial damage. A preliminary examination of the engine revealed a crack in the crankcase. A subsequent examination of the No. 1 piston assembly revealed fatigue fractures in both connecting rod retaining bolts. Additional internal engine damage was found to be consistent with damage caused by the release of the connecting rod from the crankshaft.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have returned to Bethel after first engine noise.

NTSB coding

Evidence available

  • 2 docket documents
View NTSB final reportView NTSB docket

Docket documents2

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