Pilot Debrief

CESSNA P210N near Leavenworth, WA — 2010-04-04

Final reportWPR10LA196
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Date
2010-04-04
Location
Leavenworth, WA, USA
Aircraft
CESSNA P210N
Registration
N3599P
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Cruise

Probable cause

The failure of the number two cylinder exhaust and intake valves for undetermined reasons, which resulted in a loss of engine power.

NTSB narrative

The airplane was in a cruise flight configuration when the engine ceased operating without warning. The pilot made an emergency descent and the airplane collided with a fence while landing in a field. Disassembly of the engine revealed extensive mechanical damage to the number two cylinder combustion chamber and piston assembly. The exhaust valve seat insert was missing and fragments of the insert were later found in the oil sump. The exhaust valve head had separated from the valve stem. The intake valve head had approximately 50 percent of the material separated. The fracture surfaces on the exhaust valve, intake valve and exhaust valve seat were damaged such that the mode of fracture could not be definitively determined. Hardness testing of the components indicted that they were within the manufacturer’s prescribed specifications. The sequence of fractures and separations of components could not determined.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have activated IFR flight plan before departure.

NTSB coding

Evidence available

  • 6 docket documents
View NTSB final reportView NTSB docket

Docket documents6

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