What happened
On 2 March 2023, at approximately 2150Z, a DJI Matrice 210 remotely piloted aircraft, registered ZT-WSI, was conducting a night surveillance mission at the Mabalingwe Game Reserve in Bela-Bela, Limpopo. The operation was being performed under beyond visual line of sight (BVLOS) regulations.
Following a pre-flight inspection that initially showed no anomalies, the aircraft climbed to 50 metres above ground level (AGL). While the flight proceeded without issue through the first 19 waypoints, difficulties arose at waypoint 20. Upon identifying tall trees in the flight path, the pilot attempted to trigger the return-to-home function. However, the aircraft failed to return as intended. Within ten seconds, the pilot lost the command and control connection with the unit. A subsequent search of the last known location revealed the aircraft had crashed into a lightning conductor, resulting in substantial damage to the propellers, camera, and camera holder.
The investigation
SACAA AIID examined the flight parameters and the circumstances leading to the loss of the aircraft. The investigation established that the pilot had relied on a colleague's previous successful flight of the same route to verify the waypoint settings. The investigation also reviewed the pilot's credentials, noting a valid Remote Pilot Licence with BVLOS ratings, and confirmed that the aircraft's maintenance and operating certificates were up to date. While weather conditions were fine, the investigation focused on the altitude settings and the physical impact with the infrastructure.
Findings
- The primary cause of the accident was the collision with a lightning conductor, which severed the command and control link and led to the crash.
- The pilot was unaware that the flight altitude was set to only 50m AGL, an altitude insufficient to clear the height of the lightning conductor.
- An improper pre-flight inspection contributed to the oversight regarding the altitude settings.
- The pilot's reliance on a colleague's prior experience with the route led to a lack of verification of the current mission's specific waypoint heights.