On May 20, 1996, an Air Tractor AT401 (registration N1019X) was involved in an aviation accident near Letcher, SD. Investigators recorded the probable cause as: the pilot's inadequate evaluation of the severe weather condition. A factor was the weather conditions. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
Pilot attempted to ferry an agricultural aircraft to another airport due to approaching storm; during takeoff a gust front caused wind shift from calm to 30 knots from west, resulting in loss of directional control and nose-over.
Accident Details
The pilot of the airplane, which had just completed an aerial application flight, reported observing lightning to the northwest of the airstrip after landing. Concerned about the approaching weather, the pilot decided to ferry the aircraft to another airport that offered hangar facilities.
Takeoff Attempt
During the takeoff roll, which was initiated toward the south, a gust front from the approaching storm reached the field. The wind conditions changed rapidly from calm to approximately 30 knots from the west. The pilot attempted to continue the takeoff but reported being 'unable to attain flying speed and maintain directional control.'
Outcome
The airplane departed the east side of the runway and subsequently nosed over. The pilot did not specify any injuries or damage in the report.