On August 16, 1997, an Air Tractor AT-301 (registration N4411S) was involved in an aviation accident near Waynesboro, GA. Investigators recorded the probable cause as: The obscured vision of the pilot due to oil covering the windscreen. Contributing to the accident was the partial loss of engine power due to a cracked head of one of the cylinders and unsuitable terrain encountered during the forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
After completing a spray application, an aircraft experienced a partial engine power loss and oil-covered windscreen. The pilot performed a forced landing on a road, but during the landing roll the airplane veered into a ditch and nosed over. Engine examination revealed a cracked cylinder head.
Accident Sequence
Following the completion of a spray application, as the aircraft was returning to the departure airport, the engine suffered a partial loss of power. Simultaneously, engine oil began to cover the windscreen, impairing the pilot's visibility. The pilot executed a forced landing onto a road. However, during the landing roll, the airplane departed the road surface and entered a ditch, causing the aircraft to nose over.
Post-Accident Examination
Inspection of the engine disclosed that the head of the No. 1 cylinder was cracked. The crack extended from one spark plug hole to the other.