Cessna 172B N8141X accident near Sisters, Oregon

Probable cause

A loss of engine power during cruise flight for reasons that could not be determined because the engine was not properly preserved to prevent corrosion after the wreckage was recovered from the lake.

NTSB analysis

The pilot was flying over a heavily wooded, remote area when the engine lost power. He restarted the engine several times, and each time the engine ran for a shorter period of time. Eventually unable to restart the engine, the pilot chose to ditch the airplane in a lake rather than descend into trees. The airplane sank in about 8 feet of water and came to rest at the bottom of the lake. The airplane was eventually recovered from the lake, but the engine was not properly preserved to prevent corrosion. The pilot reported no preimpact malfunctions or failures that would have precluded normal operation. The reason for the loss of engine power could not be determined.

Text from the NTSB. Open the NTSB docket for WPR13LA378 for the full record.