What happened
On the evening of 20 June 2023, a DJI Mavic 2 Enterprise Advanced with registration ZT-YLL was performing a surveillance mission at the Navigation Colliery Mine in Witbank, Mpumal． During the flight, which was conducted under beyond visual line of sight (BVLOS) protocols, the pilot was monitoring suspects near the West Diesel Dam. While the pilot was actively directing armed response teams to a specific location, the aircraft's smart return-to-home feature activated unexpectedly, followed immediately by a total loss of connection between the remote pilot station and the drone.
Following an unsuccessful search attempt on the night of the incident, the aircraft was located the next morning. The wreckage, which sustained substantial damage, was found with three broken propeller blades. There were no injuries to personnel on the ground and no damage to property was reported.
The investigation
SACAA AIID examined the operational history and technical state of the aircraft. The investigation confirmed that the pilot held a valid Remote Pilot Licence with the necessary BVLOS ratings and a current medical certificate. The ZT-YLL was also found to be within its mandatory periodic inspection interval, having completed its last inspection with approximately 200 flight hours remaining before the next required check.
Technical analysis focused on the power source and the physical state of the aircraft at the time of the loss of control. The investigation established that the aircraft was otherwise airworthy and possessed sufficient battery voltage for a safe return to the launch site prior to the failure.
Findings
The investigation determined that the primary cause of the crash was an inadequate pre-flight inspection, which allowed the battery terminals to remain improperly latched. This mechanical failure led to an accumulation of dust at the terminals, causing the battery to lose connection with the aircraft. As a result, the UAS suffered a sudden loss of thrust, leading to the impact with the ground.