Helicopter 'with 18 people on board' ditches in sea off Shetland Three people are missing at sea after a helicopter carrying offshore workers ditched in the North Sea off the coast of Shetland. The aircraft had 16 passengers and two crew on board when it hit the water two miles west of Sumburgh airport at about 6.20pm on Friday. Its operator said it was coming in to land when it lost contact with air traffic control. The airport, at the southern tip of Shetland, was closed as Police Scotland declared a major incident. The Maritime and Coastguard Agency confirmed 15 people had been rescued, including nine people who were brought ashore by a coastguard helicopter. Eight were described as walking wounded while the ninth was taken off on a stretcher. All those rescued were taken to Gilbert Bain Hospital in Lerwick. The helicopter is a Super Puma AS332 L2 operated by Canadian company CHC, a company that transports offshore workers to and from North Sea platforms. The helicopter was flying from the Borgsten Dolphin oil platform in the North Sea to Sumburgh airport when it went down. Three rescue helicopters and lifeboat crews from Lerwick and Aith RNLI stations were sent to the scene. The RNLI said a search was continuing for three people missing in the water. Conditions in the area were said to be foggy, with high winds earlier in the evening which have since died down. A spokeswoman for the coastguard said passengers suffered a range of injuries. She said: "The people that were involved are in varying stages of injury, no one has walked away from this without a scratch." A specialist medical team has been flown out from Aberdeen Royal Infirmary to Lerwick by the RAF helicopter from Lossiemouth, the coastguard said. A NorthLink ferry travelling between Shetland and Aberdeen via Orkney, which set sail from Lerwick at 5.10pm with about 100 passengers, turned back to assist with the rescue. The ferry was stood down from the operation at about 9.30pm and resumed its journey to Kirkwall. Lewis Anderson, one of the passengers on board the ferry, told radio station Original 106 FM: "We were told on the port that we'd be coming in late into Kirkwall, there'd been a helicopter ditched in the sea and we were going to assist the helicopters. There were two helicopters that had been taken from Sumburgh and we saw them over and over just near Sumburgh Head. There were a few orange buoys and what looked like a yellow life raft floating about. A spokesman for Police Scotland said: "The search is currently ongoing involving a number of agencies, coordinated by Maritime and Coastguard Agency and so far 15 people have been uplifted to Gilbert Bain Hospital in Lerwick. Sumburgh Airport is currently closed to allow emergency services to deal with the ongoing incident. A spokesman for the operating company said: "CHC Helicopter can confirm that an L2 aircraft has landed in the water, approximately two miles west of Sumburgh. The aircraft was on approach to Sumburgh Airport at approximately 6.20pm when contact was lost with air traffic control. The appropriate authorities have been informed and the company's Incident Management Team is being mobilised. Investigators from the Air Accidents Investigation Branch (AAIB) are travelling to the scene. A spokesman for the Department for Transport said: "The AAIB is aware of the incident and has deployed a team." The Unite union's Scottish secretary Pat Rafferty said: "Our immediate thoughts are with those people and their families and we can only hope for good news although as time goes on the situation becomes more worrying. Fifteen people have thankfully been rescued and accounted for, unfortunately some with injuries, and their rescue is testimony to the bravery and skills of the rescue services. This brings into sharp focus once again the very precarious nature of the transportation of workers to and from offshore platforms. The health and safety of working people is our priority and we will be watching events closely as they happen. The Moderator of the General Assembly of the Church of Scotland offered her prayers to those involved. The Right Reverend Lorna Hood said: "Our thoughts and prayers are with all those involved in the Super Puma helicopter crash off Shetland and especially those waiting news of their loved ones." Four years ago 16 men died when a Super Puma AS332 L2, manufactured by Eurocopter, plunged into the sea. An accident investigation found it suffered a catastrophic gearbox failure while carrying offshore workers to Aberdeen. The aircraft, operated by Bond helicopters aircraft, was returning from the BP Miller platform when it went down off the Aberdeenshire coast on April 1, 2009. More recently a different Eurocopter model, the EC225, was grounded following two ditching incidents in the space of six months last year. Fourteen people were rescued off the coast of Aberdeen in May, while another 19 were rescued after an EC225 experienced difficulty off the coast of Shetland in October. The EC225 fleet was only cleared to return to service earlier this month after extra safety checks were introduced. CHC has set up a helpline has been set up for concerned relatives.