What happened
On the morning of 10 March 2025, an Air Tractor AT-502B, registration ZS-MOUS, was performing aerial application services on a private farm near Ventersdorp. The flight was part of a new contract, and the pilot had conducted a ground survey of the area earlier that morning with a farm foreman to identify potential hazards, including electrical infrastructure.
After successfully completing three spraying passes, the pilot attempted a fourth run. During this maneuver, the aircraft struck high-voltage powerlines. The impact caused the lines to snap and become entangled with the aircraft, leading to a heavy landing in a maize field. While the aircraft suffered substantial damage and some crops were destroyed, the pilot escaped the wreckage without injury.
The investigation
SACAA AIID examined the circumstances surrounding the flight, noting that the pilot was highly experienced, holding a Commercial Pilot Licence with over 11,000 total flying hours. The aircraft was found to be fully compliant with all regulatory requirements, including a valid Certificate of Airworthiness and recent annual inspections. The investigation confirmed that no mechanical defects contributed to the event.
Investigators focused on the environmental conditions and the pilot's situational awareness. Although the pilot was aware of the powerlines' existence due to the morning's ground reconnaissance, the investigation looked into why the obstacle was not avoided during the low-level flight.
Findings
- The primary cause of the accident was the pilot's failure to maintain adequate visual separation from known obstacles during the low-level operation.
- A significant contributing factor was the presence of cloud shadows, which obscured the powerlines and reduced the pilot's ability to identify the hazard.
- The pilot's lack of prior flight experience at this specific site increased the operational risk.
- The investigation noted that the accident might have been prevented if the powerlines had been equipped with high-visibility markers.
Safety action
To mitigate the risks of obstacle strikes during agricultural operations, the following safety measures are recommended:
- Physical marking of hazards like powerlines with high-visibility devices.
- Supplementing ground surveys with aerial reconnaissance and detailed obstacle briefings using GPS data and photos.
- Utilizing GPS-based guidance systems to improve situational awareness during low-level maneuvers.
- Implementing standard risk assessments for all new operational sites.