On July 26, 2003, an Air Tractor AT-301 (registration N23820) was involved in an aviation accident near Rhinebeck, NY. Investigators recorded the probable cause as: A loss of engine power due to a failure of the number eight cylinder. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During cruise, an engine vibration and power loss forced a pilot to land in a field. Post-accident examination found a cylinder head separation. The engine had 930 hours since overhaul.
Incident Summary
During cruise flight, the airplane's engine began to vibrate and lose power. The pilot was unable to maintain altitude and performed a forced landing to a field.
Engine Examination
The airplane was equipped with a Pratt and Whitney R1340 radial engine. Examination of the engine revealed that approximately 50 percent of the number eight cylinder head was separated from its respective cylinder barrel.
Maintenance Records
Review of maintenance records showed that the engine had been operated for about 930 hours since it was last overhauled and about 20 hours since its most recent annual inspection. At the time of the annual inspection, a mechanic reported he examined the cylinders and did not detect any cracks.