What happened
On the evening of 8 January 2023, a UAV Drone Solutions Condor (registration ZT-XFN) was performing a BVLOS aerial survey at the Anglo American Mine Amandelbult in Limpopo province. The flight was being conducted under night visual meteorological conditions as part of a surveillance operation.
After a successful takeoff with high battery levels, the aircraft operated normally for approximately 20 minutes. However, the flight log indicates that at 2026Z, the aircraft triggered a return-to-launch (RTL) failsafe. The pilot attempted to cancel this function to continue loitering, but shortly thereafter, the aircraft lost its data link with the ground station. The RPA failed to return to its launch point and disappeared. Following an extensive search, the aircraft was discovered 10 days later approximately 0.3 nautical miles from the launch site, suffering substantial damage to its fuselage, wings, and equipment. There were no injuries reported.
The investigation
SACAA AIID examined the flight logs and telemetry provided by the operator. The investigation confirmed that the pilot held a valid Remote Pilot Licence with the necessary BVLOS rating, and the aircraft and operator held all required regulatory approvals and certificates. The investigation focused on the technical telemetry recorded during the final moments of flight.
Findings
Analysis of the flight data revealed significant spikes in battery current during the flight. These electrical surges led to an increase in the revolutions per minute (RPM) of the number 1 and 4 motors. This sequence of events was triggered by the failure of the Electronic Speed Controller (ESC). As a result of this failure, the aircraft experienced a 180-degree roll, causing it to bank sharply, lose altitude, and ultimately crash. While the mechanical failure of the ESC was identified, the specific reason for the battery current spikes and the ESC failure could not be determined.