What happened
On the morning of 4 May 2022, a DJI Matrice 300 RTK drone, registered as ZT-XJD, was operating at the Seriti Middelburg Mine in Mpumalanga Province. The flight was being conducted by a licensed remote pilot under Part 101 regulations. Following a successful pre-flight inspection and an uneventful takeoff, the aircraft reached a hover altitude of approximately 260 feet. During the flight, the pilot heard an unusual noise, after which the drone began to spiral toward the earth. The pilot realized that only three of the four propulsion motors remained functional. The aircraft sustained substantial damage and was destroyed upon impact with the ground.
The investigation
SACAA AIID reviewed the circumstances surrounding the crash, noting that the aircraft had been maintained approximately 11 hours prior to the incident. Meteorological data from Witbank Aerodrome indicated favorable flying conditions with light winds and clear skies. The investigation noted that the operator did not take on-site photographs or video of the wreckage before recovering the drone. Furthermore, the accident was reported to the authorities 14 days after the event, which exceeded the required 24-hour notification period. While the drone was sent to a local distributor under warranty, no official manufacturer report was available to the investigators.
Findings
- The primary cause of the crash was the in-flight failure of one propulsion motor.
- The drone failed to activate its automated Three-Propeller Emergency Landing mode.
- The aircraft entered an uncontrollable descent and was destroyed upon ground impact.
- There were no injuries resulting from the accident.
Safety action
- The investigation highlighted a need to review the manufacturer's safety documentation, specifically regarding the claim that a safe landing can be achieved during an automated emergency spiral, as attached payloads may alter the aircraft's center of gravity.
- A safety message was issued to remind remote pilots and operators to report accidents before recovering aircraft to prevent the loss of critical evidence and ensure thorough investigations.