What happened
On 27 March 2023, a DJI Mavic 2 Pro was being operated for university research purposes in Liverpool. The aircraft, owned by a university that was registered as an operator with the CAA, was being flown by a research student. This was the student's first flight with any unmanned aircraft, and they had received no prior training.
The flight was initiated from a third-floor window of the student's living quarters. After approximately three minutes of flight, while the aircraft was at an altitude of 10 meters, the pilot attempted to increase the drone's height. During this maneuver, the pilot inadvertently pressed the forward/backward control stick instead of the up/down stick. This caused the aircraft to move toward the building, resulting in a collision with the wall. The impact caused the aircraft to fall to the ground, resulting in extensive damage to the arm modules and the camera gimbal. No injuries were reported.
The investigation
The AAIB examined the aircraft and analyzed the flight logs. Analysis by the manufacturer confirmed that the DJI Mavic 2 Pro was functioning normally and showed no signs of mechanical or software malfunction prior to the impact. The logs indicated the aircraft was operating in 'positioning mode' at the time of the accident.
The investigation also looked into the drone's obstacle avoidance capabilities. While the aircraft is equipped with a vision system designed to detect and avoid obstacles, the effectiveness of this system is dependent on sufficient lighting, textured surfaces, and the specific flight mode being used. The investigation could not determine why the vision system failed to detect the building during this specific encounter.
Findings
- The pilot was operating the aircraft without any prior training or flight experience.
- The pilot did not hold the necessary A2 Certificate of Competency required for this category of operation.
- The accident was caused by the pilot's accidental input of the forward/backward control lever instead of the vertical ascent command.
Safety action
Following the incident, the university implemented several new safety protocols, including:
- Mandatory logging of all unmanned aircraft with the Safety Adviser’s office.
- Assignment of a responsible person to every aircraft.
- Implementation of secure storage and access procedures.
- Requirement for all pilots to complete the A2 CofC course and attend official safety training sessions.