Eighteen passengers and crew have been rescued after their helicopter crashed in to the North Sea from where they were plucked to safety.Three military helicopters and a Nimrod aircraft joined the rescue operation. Fortunately the downed aircraft landed upright in the freezing waters and the two crew and 16 passengers – all oil and gas workers – were able to get into dinghies. Michael Coull Watch Officer Aberdeen Coastguard said: “They have been checked over by medics of Bond Offshore on board the aircraft and on board the vessel and other than slight hyperthermy and obviously shock there are no significant injuries to report.” The Super Puma helicopter went down about 190 kms off the coast of Scotland as it was coming in to land at an oil platform. There are around fifty helicopter flights a day to the oil and gas platforms out of Aberdeen in Scotland and the safety record is considered to be generally good. An investigation is underway into the cause of the accident to find out why the helicopter, owned by Bond Offshore, ditched into the North Sea. The weather was reported fair at the time, with a sea swell of about three metres.