What happened
On 10 November 2022, a pilot was conducting a multispectral scanning operation of a yacht near Granger Bay, Western Cape. Operating a DJI Matrice 210 with registration ZT-WKE, the pilot launched the aircraft from a support boat approximately 50 metres from the target vessel. The flight was conducted under visual line of sight (VLOS) in accordance with Part 101 regulations.
Roughly 15 minutes into the mission, while the aircraft was hovering at 50m above sea level, the pilot heard an unusual noise. Immediately following this sound, the aircraft began a rapid descent. The pilot attempted to compensate by increasing throttle and maneuvering the aircraft away from the yacht to avoid a collision. However, during the descent, a propeller blade was seen floating in the water, indicating a mechanical failure. The aircraft struck the ocean surface and submerged; despite immediate efforts by the pilot and the boat's skipper to reach the site, the DJI Matrice 210 could not be recovered. There were no injuries and no damage to property reported.
The investigation
The SACAA AIID examined the flight logs and manufacturer data to reconstruct the final moments of the flight. Analysis of the post-accident log revealed that the aircraft lost control during the final two seconds of flight. The data showed the pilot applied forward and upward stick inputs, suggesting an urgent attempt to avoid an obstacle or stabilize the craft, after which the drone's power cut out.
Prior to the accident, the aircraft had undergone a mandatory periodic inspection on 19 October 2022. That inspection had confirmed the motor system was functioning correctly, the propellers showed no signs of stress or damage, and the battery was in good condition. At the time of the incident, the aircraft had flown only three hours since that last inspection.
Findings
- The primary cause of the accident was the detachment of a propeller blade during flight, which resulted in an immediate loss of control.
- The specific reason why the propeller blade separated from the aircraft could not be determined.
- The pilot was properly licensed with a valid medical certificate and the operator held the necessary certificates for the operation.