AAIB investigation to DJI Matrice 210, UAS, registration n/a
Electronic Speed Controller failure, Feltham, London, 18 February 2019.
Summary:
A few days before this accident, the aircraft had sustained light damage which included the area around motor No 1 and its associated electronic speed controller (ESC). Following some minor repairs being made by him, a test flight was being carried out by the operator’s Chief Pilot at a disused rail yard in light rain. He assessed the current weather conditions as being suitable and checked the forecast which was for low winds and light rain. He carried out the pre-flight checks, including a check of the security of the batteries.
During the initial part of the test flight the aircraft performed as expected. However, towards the end of the test flight, when the aircraft was established in a low hover, a loud mechanical noise was heard, and it was seen to tumble to the ground.
The damaged aircraft was sent to the manufacturer for repair who reported that the motor No 1 ESC had failed during flight. It was not possible to establish whether the earlier light damage observed in the area around motor No 1 was a factor in this accident.
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