On May 5, 1994, an Air Tractor AT-402 (registration N91966) was involved in an aviation accident near Sikeston, MO. Investigators recorded the probable cause as: Failure of one compressor blade due to high cycle fatigue, which then resulted in further compressor and turbine blade damage in the engine, leading to a total loss of engine power. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
Immediately after takeoff, a total loss of engine power occurred, and the airplane pitched nose down, contacting terrain off the left side of the runway. Investigation revealed a compressor blade failure due to high cycle fatigue, leading to further engine damage.
Incident Overview
The pilot reported that immediately after takeoff, a total loss of engine power occurred and the airplane pitched nose down. The airplane then contacted the terrain off the left side of the runway. At the time of the incident, the airplane was loaded with 340 gallons of a Prowl herbicide/water mixture, which spilled upon impact.
Inspection Findings
Post-incident inspection of the engine revealed a failure of one compressor blade. This failure was determined to have occurred due to high cycle fatigue. The initial compressor blade failure subsequently resulted in further damage to additional compressor and turbine blades within the engine.
Operational Circumstances
The airplane had been loaded with 340 gallons of a Prowl herbicide/water mixture for agricultural application. The mixture spilled when the airplane contacted the terrain. No further details regarding the specific aircraft type, registration, or pilot information were provided in the investigation source.
Probable cause
Failure of one compressor blade due to high cycle fatigue, which then resulted in further compressor and turbine blade damage in the engine, leading to a total loss of engine power.