What happened
On 15 October 2022, a DJI Matrice 300 RTK (registration ZT-XNE) was deployed for aerial surveillance tasks at the Anglo American Mogalakwena Mine in Limpopo Province. Operating under visual line of sight (VLOS) in accordance with Part 10-1 regulations, the pilot launched the aircraft with 94% battery power. The mission involved monitoring the ‘Big Mike Stockpiles’ and was nearing completion when the battery level reached approximately 10%.
While the pilot observed the aircraft returning to its home base via the controller display, the Command-and-Control (C2) link unexpectedly severed. Although brief disconnections are common, the link failed to reconnect. The pilot attempted to trigger the Return-to-home (RTH) function, but the aircraft remained unresponsive. Following the loss of control, a search was initiated using another RPA, which eventually located the downed aircraft in the mine's south pit. The aircraft was recovered later that day with substantial damage to its propellers, antennae, and the front right arm.
The investigation
The SACAA AIID investigation reviewed the pilot's credentials, the aircraft's maintenance history, and the operational procedures in place at the time of the incident. The investigation confirmed that the pilot held a valid Multirotor Remote Pilot Licence and a current medical certificate. The aircraft, ZT-XNE, had undergone a scheduled maintenance inspection only a few hours prior to the flight and possessed a valid Letter of Approval.
Investigators specifically examined the battery management protocols. While Civil Aviation Regulations (CAR) 101.05.23 require a minimum 10% power reserve for VLOS operations, the manufacturer's operating manual for the Matrice 300 series specifies that the aircraft should land when the battery reaches 20%.
Findings
- The primary cause of the accident was the loss of the Command-and-Control (C2) communication link between the controller and the RPA.
- This loss of communication was directly triggered by the battery power dropping below the critical 10% threshold.
- A significant contributing factor was the pilot's failure to adhere to both the manufacturer's operating manual—which mandates landing at 20%—and the regulatory requirements regarding power reserves.