A helicopter pilot died after a boat he was lifting struck part of his aircraft, a sheriff has ruled.
Peter Clunas, 59, was carrying out work on a fish farm in North Uist when the accident happened.
The small boat being lifted became unstable and flew upwards causing the lifting line to strike the helicopter’s tail rotor.
The Aberdeenshire-based pilot’s machine then became ‘uncontrollable’ and plunged into the water of Loch Scadavy in June 2018.
Mr Clunas, of Newburgh, was the only person aboard the AS350 Squirrel aircraft.
A fatal accident inquiry held at Lochmaddy Sheriff Court has ruled nothing could have been done to prevent the tragedy and no reasonable precautions could have stopped it.
In a written ruling, Sheriff Gary Aitken said: “So far as the cause of the accident which resulted in Mr Clunas’ death is concerned, it is also clear that the accident was caused by the underslung boat being carried by the helicopter flying up, the lifting chain connecting the boat to the helicopter striking and damaging the tail rotor of the helicopter and the lifting chain becoming wrapped round the tail rotor boom of the helicopter.
“This impact caused significant damage to the helicopter and rendered it uncontrollable in the circumstances.
“It is clear that in the matter of seconds which passed between the impact with the tail rotor and the impact with the water Mr Clunas did react and take remedial action.
“He released the external hook on the underside of the helicopter. He clearly made control inputs to the helicopter. However, there simply was insufficient height and time for him to bring the helicopter under control.”
Sheriff Aitken added: “The more complex question is what caused the boat to fly up in the first place, allowing the lifting chain to come in contact with the tail rotor and tail rotor boom. That question cannot be answered with certainty.
“Despite a full and thorough investigation a conclusive view cannot be taken as to which, if any, of these factors caused the boat to swing up. As already noted, it is not open to me to engage in speculation.
“The reality of life is that sometimes tragic events happen, and we are unable to determine why.”
Mr Clunas was survived by his partner and two sons, Alasdair and Bob, from a previous marriage.
In a statement following his death, his heartbroken family said: “We would like to thank emergency services for all their efforts at the scene of the accident.
“Peter was a larger than life character who loved flying. He was a keen cyclist and swimmer.
“He will be missed by all who knew him.”
An Air Accident Investigation Branch (AAIB) report earlier said the helicopter crashed into the loch after the boat became unstable.