The UK oil and gas industry prides itself on having what it believes is the best helicopter safety record in the world.
Super Puma helicopters are the workhorse of the North Sea
But a series of tragedies over the past 30 years have brought regular reminders of the dangers still faced by the 18,000 workers employed offshore.
More than 100 people people have now died in helicopter accidents in the 30 years since drilling began in the North Sea, with more than 30 crashes or safety incidents being reported in that time.
And although regulations were tightened up after the Piper Alpha fire in 1988, there continues to be a human cost for more than 36 billion barrels of oil produced since it was discovered in the North Sea in the late 1960s.
The worst helicopter disaster came in 1986, when a Chinook travelling from the Brent field crashed just a minute's flying time away from Sumburgh airport in Shetland, resulting in the deaths of 45 people.
The Air Accidents Investigation Branch later blamed inadequate testing and inspection programmes for the mechanical failure suffered by the helicopter.
The earliest deaths were in 1981, with 13 killed when a Wessex helicopter crashed into the sea 12 miles off the coast of Norfolk as it returned to Bacton.
The previous day, a Bell 212 crashed on its way back from the Dunlin oil platform off Shetland, killing one worker.
Safety regulations were tightened up after the Piper Alpha tragedy
In 1990, six men died when another Sikorsky helicopter struck the Brent Spar oil storage platform in the North Sea, while the following year saw three killed in a crash during maintenance work at a platform in the Ekofisk field.
A further 11 men were killed in 1992 when their Super Puma helicopter crashed into the North Sea during a routine 200-yard flight from Shell's Cormorant Alpha rig to a nearby accommodation barge.
Thirteen men died when a twin-engined Wessex helicopter crashed into the North Sea off the Norfolk coast in August 2001.
In July 2002, another 11 men died when their Sikorsky S-76A suffered a mechanical failure and went down off Cromer in Norfolk as they were being ferried between oil rigs. The helicopter's rotor blade was later found to have been suffering from fatigue.
And in December 2006, six workers and two crew died when a CHC Eurocopter AS365N crashed while transferring offshore workers between gas platforms in the North Morecambe offshore field.
But not all North Sea crashes have resulted in fatalities.
One of the most remarkable escapes came in January 1995, when 18 workers and the helicopter crew survived uninjured after a Bristow's Super Puma ditched in the sea after it was struck by lightning 130 miles from Aberdeen.
And in February of this year, another 18 workers were rescued after their Super Puma ditched off the coast of Aberdeen.
Speaking after that incident, Chris Allen, health, safety and environment director industry regulator for Oil & Gas UK, said UK helicopter operations were the "safest in the world".
He paid tribute to the oil and gas industry's commitment to improving offshore safety over recent decades through investment in research, new systems and new aircraft.
But he added: "While this is the safest region in the world for helicopter operations, the UK oil and gas industry will not rest on its laurels.
"It is determined to continually improve and, notwithstanding the economic downturn, 2009 will see additional multi-million pound investment to further improve helicopter safety."
On its website, Contractors Unlimited, a service for freelance engineering contractors and small businesses, said: "Safety is always the top concern offshore.
"Admittedly, there have been accidents, some of them major - Piper Alpha for example.
"However, things have improved dramatically, and the culture offshore has changed. The industry is proud of its safety record over the last few years and workers are encouraged to report any health, safety or environmental problems."