On July 15, 1993, an Air Tractor AT-401 (registration N1009T) was involved in an aviation accident near Dermott, AR. Investigators recorded the probable cause as: Pre-existing crack and subsequent total failure of the master rod. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
While banking after fertilizing a rice field, the engine lost power. A forced landing in a flooded field led to the aircraft sinking and nosing over. Post-crash inspection found a pre-existing crack and failure of the master rod.
Accident Summary
The pilot had just finished applying fertilizer to a rice field and was banking the aircraft to return to the airstrip. During the banking maneuver, the engine suddenly lost power. The pilot executed a forced landing, touching down in a flooded rice field. Upon contact, the wheels sank into the water and soft ground, causing the airplane to nose over.
Engine Examination Findings
Following the accident, the engine was disassembled for examination. The post-accident disassembly revealed evidence of a pre-existing crack in the master rod, which had subsequently undergone total failure. The engine had been overhauled two weeks prior to the accident.
Probable cause
Pre-existing crack and subsequent total failure of the master rod.