Saving lives in helicopter crashes at sea
Twenty people dead. Five aircraft in the water. The helicopters that ferry oil and gas workers over the North Sea have had a poor safety record in the past few years. Yet they carry a million passengers every year.
So now the BBC has been given the first chance to try out a new safety device that could save lives in the future.
It combines a life jacket with a very small aqualung - and the Civil Aviation Authority, which regulates safety, is rolling them out 15 months early as one of a number of new rules.
I was given the chance to test out the new system in a special Survivex training pool in Aberdeen. Here's what it was like to use the current safety kit.
Before trying out the new life jacket I got a chance to try the current one, as a comparison.
That meant spending a chunk of my morning strapped into a pretend helicopter, upside down in a swimming pool, being battered with rain, waves, wind and fake lightning.
Oh, and in the dark too. To put it mildly, it's a bit intimidating.
The current system is called a hybrid re-breather, which is a life jacket with a rubber bag full of air that you continually re-breathe through a tube.
This gives you a few precious extra minutes if the helicopter sinks or flips over - that's the worst bit, when the aircraft spins over so you're upside down.
Here's a terrifying fact, about 60% of helicopters invert or sink either straight away or after a short delay once they hit water.
"Don't try to get out straight away," the instructor Kieran Morrison told me. "Once the water goes over your head, count to seven. And stay strapped in until the last minute."
So in effect, you have to sit quietly, strapped in, and count, while gallons of water rush over you and you flip over. Talk about fight your instincts.
But as Kieran explained, if you unstrapped too soon you'd float to the top of the helicopter, which is what used to be the floor, and that makes it incredibly hard to pull yourself down to your escape hatch, the window.
The survival suit makes you float, which is a good thing unless you're still inside the aircraft.
You also have to put a nose clip on one-handed, which is incredibly fiddly. The other hand stays, at all times, on the window release lever.
I had quite a few goes and found I could breathe OK with the re-breather, but it's not clean air, it feels a little strained. And the rubber bag you're filling is just that. Rubber. It can potentially wear, or leak.
There's also a metal pin you have to remember to push in as soon as you reach the surface. Otherwise you might get a stomach full of sea water.
The whole thing felt fine to use, but those fiddly little things, the nose clip, the pin, well, would you really remember them if it was a real crash?
Here's the new kit in action.
By contrast, the new system is like a mini-version of scuba gear. It's heavier, because of the small cylinder of compressed air, but it's also less bulky.
The nose clip is attached to the mouth piece and is far easier to put on, especially one-handed. Believe me, that makes a big difference.
And once I was under the water, it was far more comfortable to breathe. I'm not a diver, I had only gone scuba-diving once, 10 years ago, but I picked this up straight away.
I didn't try the new system in a crash-scenario, just at the side of the pool, but overall it gave me far more confidence in the water.
The unions have also given it their seal of approval. "It should deliver greater confidence with the workforce," says Jake Malloy from the RMT.
"But the long-term plan must be to keep the aircraft in the air... safer, more reliable aircraft. Newer aircraft, bigger windows, more space."
'I could hear people screaming'
My day's training was nerve-wracking enough, but of course it's nothing compared to a real accident.
We spoke to James Nugent, a platform worker who was snoozing while his helicopter approached Sumburgh airport in the Shetland Islands in August last year,
"You just knew that we were falling out of the sky. I saw this window being pushed in, and the water coming over my lap and face and being knocked out, anything up to 45 seconds to a minute.
"When I came to I realised I was upside down, submerged in water. And I instinctively undid my seat belt...swimming for the window...gave it a couple of kicks...broke the surface of the water and I realised I was OK.
"I could hear people screaming and shouting and people were thrashing about in the water."
Four people were killed in that accident, which experts are still investigating.
James is not impressed with the new rules and equipment the Civil Aviation Authority is bringing in.
"They talk about survivability rate when one of these helicopters goes into the sea.
"As far as I'm concerned, what they are saying is it's totally acceptable for these helicopters to be falling out of the sky."
He wants a total redesign so that helicopters don't come crashing down and don't sink or flip over if they hit water.
This new breathing system will be available to some offshore workers within weeks, and everyone should be using one by the beginning of next year.