Drone Manufacturer: DJI
Drone Model: Matrice 210
Country: United Kingdom of Great Britain and Northern Ireland
Type: Accident
Date: 2018-10-15
Applies: Daytime
Pilot Qualifications: Unknown Status
Pilot Flight Experience: 6 Hours
Link to External Information About This submission: https://www.gov.uk/aaib-reports/aaib-investigation-to-dji-matrice-210-uas-registration-n-a-15-october-2018
File Uploaded: dji_matrice_210_uas_registration_na_151018_0120
Description
Synopsis
Whilst hovering at a height of about 50 m over a building, one of the propeller motor electronic speed controllers failed, causing the aircraft to drop vertically and crash into the roof of the building. History of the flight
The DJI Matrice 210 quadcopter small unmanned aircraft (SUA)1 , with a takeoff mass of 5.83 kg, was being used in support of an operation to target vehicle crime at a shopping centre. All flights were to be conducted over buildings to reduce risk to the public. It was reported that it was drizzling with a light wind. It was considered that the weather did not preclude flight as the aircraft had an IP432 rating.
The accident occurred during the second flight of the day. After takeoff the pilot checked the controls and the aircraft responded normally. After about 8 to 10 minutes of flight the pilot brought the aircraft to a hover about 50 m above the roof of a shopping centre building. About one minute later, the aircraft suddenly dropped vertically and crashed into the roof of the building (Figure 1). The pilot had not made any control inputs and it was stated that there had been no warnings on the controller. The aircraft suffered severe damage (Figure 2).
Refer to report on DJI Matrice 210 – EW/C2019/03/02 in this AAIB Bulletin 1/2020 for information on other accidents involving the DJI Matrice 210 and Safety Recommendations concerning the safe operation of a UAS near to people and congested areas.
Reported Cause
The recorded data from the aircraft indicated that the batteries were functioning normally and there was 22.8 V and 65% charge remaining on both batteries when it had hit the building. The manufacturer reviewed the data and confirmed that the loss of power which led to a loss of lift and control was caused by failure of the No 4 (right front) motor electronic speed controller.