A drone being used for filming a television series struck a sea stack and fell into the sea below, an investigation has found.
The machine was being flown at Mangersta on the Isle of Lewis to “capture cinematic shots”.
It drifted sideways and struck a stack – a column of rock rising from the sea – and crashed. It was not recovered.
The Air Accident Investigation Branch (AAIB) investigates accidents involving drones as part of its work.
Its investigation said the drone’s obstacle avoidance system did not detect the stack, give warning of an imminent impact or automatically avoid the rock.
The incident occurred on September 15.
“The flight log for the UAS (unmanned aircraft system) showed that it was travelling at 6.5 mph at the last recorded data point,” said the AAIB.
“Whilst the UAS was being flown near to the Sea Stack, it either drifted or was flown too close to the feature before it struck the Sea Stack and then fell into the sea below it.
“The UAS pilot stated that the accident happened very quickly. He and the observer did not know exactly what had happened, but the last recorded images showed the sea stack coming into view before the image recording ended, with the UAS flying sideways towards it.
“The flight log did not show any errors and there was no suggestion of a technical failure. The obstacle avoidance system did not detect the stack, give warning of an imminent impact or automatically avoid the stack. Prior to impact, the UAS had been holding its position adequately in the air in wind speeds of up to 8 m/s (15.5 kt). The UAS was not recovered so the cause could not be determined.”
