The discovery was made yesterday by investigators as they worked in thick fog to remove the fuselage from the North Sea, where the Super Puma AS332L2 plunged into the North Sea near Sumburgh Airport with 18 people on board on Friday night.
Oil rig caterer Sarah Darnley, 45, of Elgin, fellow industry contractors Gary McCrossan, 59, from Inverness; Duncan Munro, 46, from Bishop Auckland; and George Allison, 57, from Winchester, died after the helicopter suffered a "catastrophic" loss of power coming in to land as it returned from Borgsten Dolphin oil platform.
A book of condolence is to be opened at 10am today at the oil chapel at St Nicholas Church in Aberdeen.
Oil company heads are also due to meet to discuss the impact of the crash on manpower levels and production, given the flow of workers has been restricted following the grounding of all 33 Super Puma helicopters serving the North Sea oil and gas industry.
Two oil workers remain in Gilbert Bain Hospital in Lerwick suffering from exposure, with 12 other victims of the crash now released from medical care and back in Aberdeen.
A team from the Air Accidents Investigation Branch is now in Shetland to pinpoint the cause of the fatal crash, with the pilot and crew member potentially to be interviewed following the initial mechanical analysis.
The development comes as oil workers called for the industry to halt the use of Super Pumas, given the helicopters have been involved in five North Sea emergencies since 2009.
Chief Inspector Angus MacInnes last night spoke of the difficult conditions facing those involved in the recovery of the craft. He said: "The North Sea is an extreme environment which has posed challenges for the recovery operation, not least the weather conditions we have seen over the past 24 hours. Friday's incident has had a huge impact on those who work or have relatives in the oil and gas industries, but also the communities in Shetland and Aberdeen. There is a tangible sense of mourning and shock in the area and there is unlikely to be anyone who hasn't had this on their minds over the past few days."
The swift response by the Maritime and Coastguard Agency (MCA), RNLI and other emergency services may have prevented further fatalities, he said.
Mr MacInnes added: "In the north of Scotland we have had responsibility for policing the offshore industry for several decades and regrettably we have considerable experience and expertise in dealing with this type of event."
With the gounding of the 33 Super Pumas - more than half of the helicopter fleet that services the North Sea oil and gas industry - MSPs and trade unions warned oil and gas production levels could fall if insufficient numbers of workers were able to reach the rigs, should transport problems persist in the long term.
Alex Johnstone, Conservative MSP for North East Scotland, warned that if the transport issues continued for weeks, production could fall "significantly".
He said: "If anything interferes with the investment and development in the North Sea, it will have limited effect on production initially. However, ultimately the drop in production will accelerate if these problems cannot be overcome. The situation will inevitably get worse as time goes on."
John Taylor, regional officer for Unite, said: "There is a 50% reduction in the number of helicopters available to move people off shore so that will either
mean an alternative mode of transport is found or you may have to look at reducing the numbers who are working off shore. The industry is meeting to start to look at the ramifications of a long-term situation where 50% of the helicopters are suspended."
He added the industry could seek out alternative helicopters - a move he described as extremely difficult - or use ships to carry workers, an option fraught with safety issues, especially in poor weather.
It is not known how long the Super Pumas will be suspended and a meeting to review the decision taken by the industry's Helicopter Safety Steering Group will be held on Wednesday.
Mr Taylor said trade unions would not be recommending the suspension is ended until it had been assured the aircraft are trustworthy. "Until we have a reason to believe that these helicopters are safe, we will not support the suspension being lifted," he said.
David Petrie, external affairs officer for Oil and Gas UK, the industry body, said: "Until we know exactly what happened on Friday, we don't know how long-term the effect will be."