AAIB investigation to Parrot Anafi Thermal (UAS registration n/a) 110620
Loss of control due to propeller failure, near The Dicker, East Sussex, 11 June 2020.
Summary:
The operator was conducting training with the UAS for a pilot and observer. About 3 minutes after takeoff the UA was observed to be “twitching”. Despite attempts to regain control, it was observed to pitch, yaw and change height by approximately ± 20 ft, and the UA was flown to the emergency landing area.
As the pilot descended the UA for landing it became less responsive. It then pitched down and flew away, without any input from the pilot, and did not respond to any subsequent inputs. The pilot selected the ‘return to home’ function, without effect, and announced “control lost” to the observer. The UA then collided with a tree about 420 ft from the landing area and 100ft agl, sustaining damage to its gimbal and front right folding propeller. The operator believed that the flight characteristics and damage sustained indicated that the right front propeller failed in flight.
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