Five people have now been confirmed dead and a massive SAR operation is continuing for a further six who had been on board.
The S76 was on a routine trip from Norwich airport to rigs in the North Sea. It left Norwich at 1900 BST on Tuesday with nine workers and two crew on board, flew to the Clipper platform, and then continued to the Santa Fe Monarch drilling rig.
It was on this leg of the journey that the helicopter crashed, two miles from the rig.
Staff on the Santa Fe Monarch rig made the call to the coastguard saying the helicopter had gone down.
An RAF Sea King from Wattisham in Suffolk was scrambled and five bodies were recovered from the water within two hours. The Sea King was stood down in the early hours of Wednesday morning and the search was continued by coastguards and rig support vessels and lifeboats that had been in the area. They are concentrating on a five-mile radius of sea close to the rig although no wreckage from the helicopter has been spotted.
The Duty Rescue Controller at RAF Kinloss where the operation was co-ordinated, said the search continued on Wednesday under "near perfect conditions". He said: "We still have not found survivors and we fear that this points to a worst case scenario."
The two crew on board worked for Bristow, three of the passengers were Shell staff, three worked for engineering firm Amec and two for Amec subcontractors. The remaining passenger was from Oil Field Medical Services.