What happened
On 4 May 2022, a DJI Agras T30 agricultural drone, registered ZT-XIY, was conducting crop-spraying operations at Lincoln Farm in the KwaZulu-Natal province. The mission was being performed under visual line of sight (VLOS) in accordance with Part 101 regulations. Prior to the flight, the pilot had identified an electrical power line as a potential hazard and programmed a specific A-B route designed to fly over the obstacle to prevent a collision.
During the operation, the aircraft was flying at an altitude of approximately 7 metres above ground level. As the drone approached the power line, its onboard sensors detected the obstacle and triggered the automated obstacle avoidance feature, which caused the aircraft to pause its movement. To resume the mission, the pilot transitioned the aircraft into manual operating mode. During this manual maneuvering, the aircraft moved into close proximity to the power lines, resulting in electrical arcing. This contact electrified the drone, triggering a fire and causing the substantial damage of the aircraft as it fell to the ground. No injuries to persons on the ground were reported.
The investigation
The investigation reviewed the operational history and regulatory standing of the involved parties. The pilot held a valid Remote Pilot Licence (RPL) and a current Class 2 medical certificate. The operator held a valid Remote Operating Certificate (ROC) and the aircraft possessed a valid Authorised Release Certificate (ARC) for airworthiness. Records indicated that the aircraft had very low flight hours at the time of the event, with recent functional system tests completed in April 2022.
Findings
- The aircraft's automated sensors functioned as designed by detecting the power line and pausing the flight to prevent a collision.
- The electrical arcing occurred when the pilot attempted to manually regain control of the aircraft following the automated pause.
- The transition to manual mode brought the aircraft too close to the energized power lines, leading to electrification and subsequent fire.