Air accident investigators in Norway say the helicopter which crashed off the coast, killing all 13 people on board, gave no mayday call before it went down.

The victims, including oil worker Iain Stuart from Laurencekirk, were on board the Airbus EC-225 aircraft when it crashed near the city of Bergen on Friday.

Eyewitness footage showed the rotor blades still spinning in mid air after the helicopter crashed.

On Sunday, it emerged a warning light in the helicopter had come on earlier in the week. Operators CHC said two parts were replaced on the aircraft.

It then passed a test flight and carried out six successful commercial flights the day before it crashed.

Norway’s Accident Investigation Board say their investigation so far has shown no evidence of a mayday signal. A team of investigators from the UK has travelled to Norway to assist with the inquiry.

A petition calling for the Civil Aviation Authority (CAA) to remove all Super Pumas from service has attracted thousands of signatures since the tragedy.

On Sunday, Mr Stuart’s family released a statement saying they had been left “devastated”.

They said: “We as a family are devastated at the loss of Iain in Friday’s tragic helicopter crash in Norway.

“Iain was a loving husband and devoted father to his two children and as a family we are heartbroken. He was a caring son, brother, uncle and friend to many.

“We are appreciative of all the messages of support and kind thoughts.

“We now ask, as a family, that we are allowed some privacy at this difficult and sad time to grieve and come to terms with our loss.”

It emerged at the weekend that the same helicopter had showed signs of faults several days before the crash, returning to base on Tuesday after a warning light indicated possible technical trouble.

Aircraft operators CHC said engineers changed components on the helicopter before it was cleared to fly again on Wednesday.

A spokeswoman for the firm said: “At all times, CHC has met or exceeded the requirements of our regulatory authorities and our customers, and continues to offer a compliant service.

“Speculation about the cause of the accident is unhelpful and we must also be careful to respect the feelings of the families who perished in the tragic events of Bergen.”

Danny Lonie, managing director of offshore training firm Allied Training, was due to fly back to Scotland on the helicopter the day it crashed.

He said: “We were aboard the Safe Caledonia and were due to be picked up by the helicopter on Friday at 1pm. We heard about the crash at 12.30pm but we didn’t realise it was our chopper at the time.

“Another helicopter flew us back to Amsterdam and then on to Aberdeen on Saturday. It’s horrible what’s happened but a the end of the day it’s just machine.

“I know for a fact that every helicopter agency in Aberdeen is doing everything they can to keep people as safe as possible.

“I’ll be going back out again next week, I’m not worried.”