What happened
On 25 April 2019, a DJI Phantom was being operated for aerial work purposes at Generals Lane, Chelmsford, Essex. The mission involved conducting a survey of a field, for which the operator had used Drone Deploy software to program the flight path and establish parameters.
Prior to the flight, the operator inspected the survey area and configured the mission using the software. To ensure safety, a buffer zone was established between the flight path and the surrounding trees. However, during the final stages of the flight, the drone collided with a tree. The impact caused damage to the aircraft's arm, rotor, and gimbal. The drone was subsequently recovered from the tree.
The investigation
The investigation focused on the flight planning and the execution of the automated mission. The operator had programmed the flight using specialized software to automate the survey process. While the software allowed for the setting of flight parameters and a safety buffer from obstacles, the investigation examined why the aircraft deviated from the intended safe zone.
Findings
- The primary cause of the collision was that the pre-programmed buffer zone was insufficient to accommodate the drone's turning radius at the conclusion of one of the flight legs.