Accident Summary
On 4 May 2022 at approximately 1000Z, an Air Tractor AT-502B aircraft, registration ZS-OBR, was involved in an accident during a crop-spraying operation at Botselo Private Farm in the North West Province, South Africa. The flight, conducted under visual meteorological conditions (VMC) by day, was operated under Part 137 of the Civil Aviation Regulations. No flight plan was filed.
Aircraft and Pilot Information
The aircraft, an Air Tractor AT-502B (serial number 502B-0431), had a total of 6445.3 airframe hours. It was issued a Certificate of Release to Service on 19 December 2021, valid until 18 December 2022 or 6261.3 hours, whichever came first. The last mandatory periodic inspection was certified on 3 March 2022 at 6376.6 hours. The pilot, a 72-year-old male, held a valid Commercial Pilot Licence and a Class 1 medical certificate issued on 15 February 2022. He had 14583.5 total flying hours, with 5134.6 hours on type.
Sequence of Events
The pilot reported he had loaded his 11th load of crop-spraying solution and took off from Botselo Private Airstrip on a 290° heading. Before rotation, the aircraft accelerated to an indicated airspeed of 80 miles per hour (mph). After rotation, during the climb phase, the aircraft experienced a loss of lift. The pilot indicated that the wind direction changed from 180° to 220° shortly after takeoff, and the aircraft lost lift during climb out. The aircraft descended rapidly and crashed onto a maize field. It then nosed over and came to rest in an inverted position. The pilot was not injured. The aircraft sustained substantial damage.
Investigation Findings
The estimated weight of the aircraft at takeoff was 5669 pounds, with 250 litres of Jet A1 fuel. The maximum all-up weight for the aircraft is 8000 pounds. The airstrip used for takeoff was approximately 1318.37 metres long. Weather information from the pilot indicated a surface wind of 180° at 3 knots and a temperature of 22°C. Data from the South African Weather Service showed fine weather with surface wind from 220° at 6 knots, a temperature of 23°C, and a cloud base at 4000 feet. The recorded wind direction of southerly to south-westerly winds could have resulted in tailwinds during takeoff, requiring a longer takeoff run.
Probable Cause
The probable cause of the accident was that the aircraft did not use the entire length of the runway or road, which resulted in the pilot rotating prior to attaining the required speed to rotate, causing the aircraft's failure to climb and the subsequent crash.