The pilot reported that, during climbout on the return leg of an out-and-back flight, he noticed the engine hesitate for one or two seconds and then recover to normal operation. He continued climbing the Piper PA-28R and proceeded toward his home airport.
While approaching the airport, the engine made abnormal noises, followed by a total loss of power.
The pilot then executed a forced landing into a field near Frankenmuth, Michigan.
Post-accident examinations of the engine revealed that it had a very low quantity of oil, however no visible evidence of oil loss or indication of excess oil consumption was found.
A teardown examination of the engine revealed that all four piston connecting rods had failed. The failure signatures were consistent with a lack of lubrication.
Based on the evidence, it is likely that the engine failed due to a lack of oil lubrication, however the reason for the lack of oil could not be determined.
Probable cause: The failure of the engine due to a lack of oil lubrication for reasons that could not be determined during postaccident examinations.
NTSB Identification: CEN15LA157
This February 2015 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.