On July 13, 2000, an Air Tractor AT-401 (registration N4508Y) operated by Farmers Aerial Service, Inc. was involved in an aviation accident near Ripley, CA. Investigators recorded the probable cause as: A loss of engine power due to the separation of a connecting rod from the crankshaft. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aerial application flight experienced partial engine power loss; the pilot attempted a forced landing in a cotton field but collided with a dirt berm, causing the airplane to nose over. Engine examination revealed a separated connecting rod on cylinder No. 7.
Event Description
During an aerial application flight, the aircraft experienced a partial loss of engine power. The pilot initiated a forced landing in a cotton field. During the landing attempt, the airplane collided with a dirt berm and nosed over.
Engine Examination
Post-accident examination of the engine revealed that the connecting rod associated with the No. 7 cylinder had separated from the crankshaft. The connecting rod pieces were severely peened and damaged. Investigators were unable to determine the mode of separation. No other evidence of any preexisting failures or malfunctions was noted.
Additional Details
The engine had accumulated a total time of 5,267 hours. It had been operated for 475 hours since receiving its last major overhaul.