Drone Manufacturer: DJI
Drone Model: Matrice 300 RTK
Country: United Kingdom of Great Britain and Northern Ireland
Type: Accident
Date: 2021-08-03
Applies: Nighttime
Pilot Qualifications: Unknown Status
Pilot Flight Experience: 18 Hours
Link to External Information About This submission: https://assets.publishing.service.gov.uk/media/61dec949d3bf7f0541dab829/DJI_Matrice_300_RTK_UAS_reg_n_a_02-22.pdf
File Uploaded: None
Description
The DJI Matrice 300 RTK was being operated at night in support of RFFS operations to locate a missing person. After approximately nine minutes and 28 seconds of flight, when at a height of 63 meters, the pilot and observer heard an audible “bang or pop.” The UA initiated a three-rotor emergency landing sequence, flying in a rapidly descending arc until it struck the ground. The aircraft was destroyed.
Reported Cause
Examination of the UA and review of the log file by the UAS manufacturer identified that the left rear frame arm folded back during the flight and struck the motor. This resulted in failure of the rotor, triggering the emergency landing mode.
The UAS manufacturer considered there was a high likelihood that the locking collar at the junction of the frame arm had not been fully tightened, causing the rotor arm to fold back in flight.