NTSB Identification: CHI04LA256.
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Accident occurred Sunday, September 12, 2004 in Oconomowoc, WI
Probable Cause Approval Date: 05/30/2006
Aircraft: Claxton S-12, registration: Unreg
Injuries: 1 Fatal.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

The un-registered airplane was destroyed when it impacted the ground following an engine failure after takeoff. The non-certificated pilot was fatally injured. A witness reported seeing the airplane and hearing the engine "quit". The airplane then made a series of gliding turns before it impacted into a marsh. The witness did not see the impact. Examination of the airplane showed no anomalies with respect to the airframe or control system. The engine's pistons exhibited scuffing and scoring indicative of a seizure. The marks on the piston contained carbon deposits indicating that the engine had experienced a seizure prior to the accident flight that had not been repaired.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The loss of engine power due to the seizure of the pistons and the pilot's failure to maintain airspeed which resulted in an inadvertent stall. The previous damage to the pistons due to earlier seizure occurrences was a factor.

Full narrative available

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