LONDON, England (AP) — A helicopter ferrying workers from an offshore oil rig crash landed in the North Sea yesterday, British coast guards said, adding that all 19 people aboard had been rescued.

The Maritime and Coastguard Agency said in a statement that the Super Puma aircraft went down on its way back from a Total SA-operated rig about 30 miles (50 kilometres) southwest of the Shetland Islands, a Scottish archipelago deep in the North Sea. The CHC Helicopter Corp-operated aircraft was still floating on the surface of the water when all its 19 occupants were picked up from their life raft and brought aboard a nearby tanker, the coast guards said.

They were later flown to the Orkney Islands, a little further south.

Energy companies regularly use helicopters to move their workers to and from the offshore platforms that dot the North Sea, a vast and often unsettled body of water which lies between Britain and Scandinavia. Safety has long been a concern and Super Puma aircraft have come under particular scrutiny following a series of accidents and near-misses.

Earlier this year air operator Bond Aviation Group suspended some of its flights after a Super Puma crash landed in the North Sea. In April 2009, 16 people died when a Super Puma en route to the Scottish city of Aberdeen plunged into the sea when its gearbox failed. Only months before, another Super Puma had gone down over the North Sea — although in that case 18 people were rescued with only minor injuries.

Scotland's First Minister Alex Salmond said in a statement that the latest incident raised "understandable concerns" which he hoped would be cleared up by an investigation.

Union official Jake Molloy echoed the statement.

"We need to provide assurances — not just to the workers but to their families — that the primary means of transporting them to and from work is safe," he said.