Pilot error was the main cause of cockpit instruments not being monitored effectively before four people died in a helicopter crash in 2013, an inquiry has heard.
The Super Puma hit the sea and overturned approaching Shetland.
In his closing submission at a fatal accident inquiry, Martin Richardson for the Crown said the helicopter failed to maintain its target approach speed.
He said the Crown position was the “principal cause” was “pilot error”.
The inquiry has now concluded.
Derek Pyle, sheriff principal of Grampian, Highland and Islands, said he would make his determination in no more than four weeks.
Passengers Sarah Darnley, 45, from Elgin, Gary McCrossan, 59, from Inverness, Duncan Munro, 46, from Bishop Auckland, and George Allison, 57, from Winchester, died.
The helicopter hit the sea on its approach to Sumburgh, overturning and filling with water, but it did not sink as flotation devices were armed just in time.
Mr Richardson said the Crown wished to apologise for the “very very long time” it had taken for the fatal accident inquiry to be held.
He told the 12th and final day of the FAI the Crown position was the accident was caused because there was a failure to maintain the helicopter’s target approach speed, and that failure arose because the flight instruments were not effectively monitored by the flight crew.
He said: “The Crown position is the principal cause was pilot error.”
Ranald Macpherson, for pilot Martin Miglans, said there was insufficient evidence to reach a conclusion about the reasons for the flight instruments not being effectively monitored.
Gavin Anderson, for co-pilot Alan Bell, emphasised the actions of Mr Bell immediately before impact, when he armed the flotation devices.
Sheriff Principal Pyle said it was a “dreadful” accident which had a dreadful effect.
He said blame was not a matter he was required to determine.
He extended his personal sympathies to the families of the victims, and to the survivors.
Sarah Darnley, Duncan Munro and George Allison drowned after the helicopter hit the water.
Gary McCrossan, who had cardiac disease, died from heart failure following the crash.
The inquiry has also heard that one survivor, Samuel Bull, who was believed to be 28, later took his own life after suffering post-traumatic stress disorder.
The inquiry was previously delayed due to coronavirus measures.