What happened
On the morning of 22 February 2023, a remote pilot was conducting an aerial photography mission at the ArcelloMittal South Africa steel factory in Vanderbijlpark, Gauteng. The operation involved a DJI Mavic 2 Enterprise Advanced, registration ZT-XEA, flying under visual line of sight (VLOS) in accordance with Part 101 regulations.
Following a standard pre-flight inspection that confirmed all systems, including GPS and battery status, were operational, the aircraft was launched at 0631Z. The drone reached an altitude of approximately 387 feet above ground level. However, roughly five minutes into the flight, the controller displayed multiple electronic speed control (ESC) error messages. The aircraft ceased responding to pilot commands and entered an uncontrolled descent, impacting the ground at 0637Z. The impact resulted in substantial damage to the aircraft, though no injuries to persons on the ground were reported.
The investigation
SACAA AIID examined the flight data and technical records of the aircraft. The investigation confirmed that the pilot held a valid Remote Pilot Licence and medical certificate, and the aircraft's maintenance records showed it had been properly serviced and was in compliance with regulatory requirements.
Technical analysis of the flight data revealed that the aircraft had been operated in "sport mode" for over five minutes. This specific flight mode led to a rapid depletion of the battery voltage, as evidenced by the downward trend in power levels recorded during the flight.
Findings
- The primary cause of the accident was the rapid depletion of battery power resulting from extended use of the aircraft's "sport mode."
- This power loss caused the motors to cease operation and severed the link between the pilot's inputs and the aircraft.
- A contributing factor was a lack of situational awareness regarding active flight modes and real-time battery vitals on the controller screen.
- Weather conditions at the time of the incident were clear and favorable.