What happened
On 28 July 2019, at approximately 03:00 UTC, a DJI Matrice 210 small unmanned aircraft (SUA) was conducting an emergency services operation over an industrial estate in Bury Road, Chedburgh, Suffolk. The flight was taking place at night under conditions of light rain. Roughly 20 minutes after takeoff, while maintaining an altitude of approximately 70 m (230 ft), the aircraft experienced a sudden loss of altitude without prior warning. The quadcopter descended rapidly, striking the corrugated metal roof of a building. The impact caused damage to the structure and resulted in the destruction of the aircraft.
The investigation
Following the incident, the remains of the DJ/Matrice 210 were transported to the manufacturer for a detailed technical examination. Investigators sought to identify the mechanical or software failure that led to the sudden descent. The manufacturer's analysis focused on the propulsion system to determine why the aircraft lost stability.
Findings
- The investigation established that the primary cause of the accident was a propulsion error involving the No 2 motor.
- While the error in the motor's operation was confirmed, the specific underlying reason for this propulsion failure could not be determined.