What happened
On 14 December 2022, a Kestrel 2 remotely piloted aircraft, registered as ZT-WGG, was involved in an accident during a training session at the Houtkop AH training field near Vereeniging, Gauteng. The flight was being conducted under visual line of operating sight (VLOS) as part of Part 101 training exercises.
During the mission, which involved testing altitude hold modes, the aircraft began to drift toward the eastern edge of the training area. The pilot, attempting to manage the flight, failed to immediately implement corrective measures or switch from GPS mode. As the aircraft drifted, it became entangled in tree branches. During the subsequent attempt to recover the drone, it dislodged from the tree and fell to the ground, resulting in substantial damage to the rear arm and the right-side rear landing gear. No injuries were reported.
The investigation
An investigation by the SACAA AIID examined the pilot's credentials, the aircraft's maintenance history, and the environmental conditions. The pilot held a valid Remote Pilot Licence and medical certificate, though they possessed only 1.37 hours of flight experience on this specific aircraft type.
While weather conditions were reported as calm with a wind speed of only 6.7 knots—well within the aircraft's operational limits—the investigation focused on the pilot's handling of the aircraft. Additionally, it was noted that the aircraft was operating with an expired Letter of Approval (LOA) from the regulator.
Findings
- The primary cause of the accident was a command input error by the pilot, who failed to account for the aircraft's orientation.
- The pilot was operating the aircraft with the nose facing a direction different from the intended flight path, leading to directional disorientation.
- The pilot's lack of experience, with only 1.37 hours on the Kestrel 2, likely contributed to the inability to maintain control during the drift.
- The pilot's panic during the drift led to a delay in executing necessary corrective maneuvers or switching flight modes.