Piper PA-28-161 N3560B accident near Buchanan, Michigan

Probable cause

A failure of the engine's No. 3 and No. 4 cylinder valve lifters for undetermined reasons, which resulted in a total loss of engine power.

NTSB analysis

While in cruise flight at 3,000 feet above mean sea level (msl) the engine lost all power. The pilot executed a forced landing in a corn field. A postaccident inspection of the engine revealed the heads on the No. 3 cylinder intake valve lifter and the No. 4 cylinder intake valve lifter were fractured with a portion of the head separated. The entire head of the No.4 cylinder exhaust valve lifter was separated from the lifter body and the fractured surface on the body was completely smeared from impact damage. The extensive damage to the No. 4 cylinder exhaust valve likely indicated it was the first failure in the sequence; however, the damage precluded a determination of the failure mode. Six pieces of the separated sections from the remaining valve lifter heads were found inside the crankcase. Their fractured surfaces did not show any indications of fatigue. The engine had accumulated 1,637 hours since the overhaul. Reconditioned lifters were installed on the engine during the overhaul.

Text from the NTSB. Open the NTSB docket for CEN10LA531 for the full record.