What happened
On 27 May 2023, an Arace Sirin unmanned aircraft system, registered ZT-XOD, was performing a night-time security surveillance mission at the Harmony Savuka Mine in Gauteng. The flight was being conducted under beyond visual line of sight (BVLOS) regulations.
Immediately following takeoff, the pilot initiated the flight using the altitude hold (ALT Hold) mode. Shortly after ascending, a sudden gust of wind pushed the aircraft toward nearby power cables and a wall. Although the pilot attempted to redirect the drone, the aircraft struck the cables and the wall before crashing to the ground approximately two meters from the pilot. The impact resulted in substantial damage to the propeller blades, though no injuries were reported on the ground.
The investigation
SACAA AIID examined the flight logs and environmental conditions surrounding the event. The investigation confirmed that the operator held a valid Remotely Piloted Aircraft Systems Operating Certificate for night aerial patrol and survey operations. The pilot was also properly licensed for BVLOS operations.
Data from the manufacturer's log analysis revealed that the aircraft reached an altitude of approximately 14.3 feet AGL before drifting. While the nearest official weather station at Potchefstroom Airport recorded relatively light winds, investigators determined it was probable that a localized gust occurred at the mine site during the moment of takeoff.
Findings
- The aircraft was operating in an assisted flight mode that only provided altitude hold, which contributed to the drift.
- The accident occurred within seconds of liftoff, leaving the pilot with insufficient time to execute corrective maneuvers.
- A sudden gust of wind caused the initial deviation from the intended flight path.
- The takeoff location was positioned between buildings for safety, which limited the available maneuvering space.