Four oil workers were killed when a helicopter crashed off the coast of Shetland, north Scotland, last Friday.
The workers who died were named as George Allison, Sarah Darnley, Gary McCrossan and Duncan Munro. Another 14 were rescued from the water.
One rescue worker said the helicopter suffered a “catastrophic loss of power”.
It is the fifth time in four years that a Super Puma type helicopter flying workers to and from oil rigs has crashed in the North Sea.
One Super Puma model was allowed to return to commercial service earlier this month. It was banned for ten months due to gearbox faults following two crashes last year.
Thirty three workers had to be rescued from the sea. Sixteen workers died in 2009 in another Super Puma crash—the same model involved last Friday.
A fatal accident inquiry is set to begin in October this year after the Crown Office found there was “insufficient evidence for a prosecution”.
The oil workers union Oilc is now part of RMT union.
RMT general secretary Bob Crow said, “The entire Super Puma fleet must remain grounded until the causes of this latest event are established and dealt with thoroughly to the unions’ satisfaction.
“We will support any member who refuses to board any suspect aircraft type in light of this disaster.”
Oil workers have demanded the Super Puma fleet be scrapped.
Workers often do as much as three weeks on an oil rig and three weeks off. But oil companies prefer not to transport them by boat because it takes longer and is less profitable.
North Sea oil is estimated to be worth £1.5 trillion.
Despite the deaths contractor CHC Helicopter took two days to suspend all Super Puma flights.
There is a long history of fatal accidents and poor safety transporting oil workers to and from the rigs.
Between 1986 and 1992 as many as 60 workers died in three separate helicopter crashes. Another Super Puma crash, at Cormorant Alpha in 1992, killed 11 workers.
These deaths are separate from major accidents on oil rigs themselves including the Piper Alpha disaster 25 years ago which killed 167 people.
The oil workers union Oilc was formed out of workers’ anger at the lack of safety equipment and training after Piper Alpha.
And the Shetland Coastguard Station, part of the rescue team, was only saved from the coalition government’s cuts by a big campaign in 2011.
But the station is still short staffed.
Mike Smith, Shetland PCS union coastguard branch chair said, “There have been occasions where we’ve been down to just two people on watch (a 12-hour shift) which is crisis point.”
Protest against Super Puma flights, 9am, Tuesday 3 September at Offshore Europe Convention, Aberdeen Conference Centre