Latest posts for the topic "Investigation into Reaction Time in Skiing Accidents"

Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 14:50:51 GMT

Hey guys,

I'm a final year student at Imperial College London and am working on a project formally titled 'a feasibility study of an emergency safety parachute for a downhill skier'. I am basically investigating whether some form of parachute would in some way minimise the number and severity of injuries in skiing.

I am at the early stages of the project and am currently researching different statistics and sources of useful information that will help me to determine whether it is a realistic proposition.

I have a question that is mainly for those that have been in any accident of any severity when skiing.

I am interested in rough estimates of the time between moment of realisation that there is going to be a collision/fall and the actual moment of collision, even if all you can say is quite vague! (for example <5 seconds)

Any information would be greatly appreciated, as well as any general details of the incident.

Any views you have on the project that you would like to share would also be very helpful and valuable, as you guys obviously have a vast amount of practical experience of skiing!

Thank you, and I greatly appreciate your time and effort.

Peter

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 14:54:01 GMT

I would be impressed if anyone could make the judgment with any accuracy. My perception is that it would definitely be less than 5 seconds.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 15:41:44 GMT

There are many factors involved in skiing accidents. I think reaction time is one of the least important. Lack of general awareness, and poor anticipation are maybe more significant. The type of accident where there would be time to deploy any sort of safety device is far less common than the collision with another person, or object. Collisions happen mostly because there is not time to react. By the time you realise there is going to be a collision, it's often too late. There are many times we are looking out, and see the probability of a collision, then of course there is time to react, but it is the observation, and anticipation that prevents the collision, not the speed of reaction.

Trencher

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 16:13:19 GMT

I agree that there are many factors involved in an accident, but for my investigation it is the reaction time that is appropriate. Measures to improve upon lack of awareness and poor anticipation are matters for other safety initiatives.

In my work so far I have estimated very quick deployment times for the parachute (< 1 second in some conditions). The main drive for this project is the fact that in many accidents it is 'too late' because the skier can not take any measures to minimise the effects of the accident, but if the skier can deploy a parachute very quickly then the velocity of any collision could be dramatically reduced and it would no longer be too late.

So I am investigating the reaction time windows so as to use any data that you guys may have as a design parameter for the parachute, however small that time window is!

Thanks for your interest guys, much appreciated!

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 16:15:37 GMT

A parachute? If you were going fast the deployment of a parachute (presumably from your back) could cause you to fall regardless.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 16:24:03 GMT

Yes, but fall at a much lower velocity so as to minimise the damage.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 16:26:01 GMT

A fall avoiding a collision that could (potentially) not happen? You could be talking A-road speeds slowing you down to a crash at 20/30mph which could still cause serious injury. Not for me, sorry.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 16:31:22 GMT

I hear for touring they now sell airbags to avoid being buried, to be activated by the person behind you, in the event of an avalanche.

As for reaction times, I have found that the more skiing becomes second nature (though I am still a relative beginner) the more chance there is of putting concentration on what is going on around, wheras as an absolute beginner most of the attention goes into controlling the skis. Maybe beginners should not go out on the piste alone.

At the low speeds I normally travel at, I doubt whether a parachute would open. If it did, would it really make much difference to the braking distance for a parallel stop? But some skiers, and especially boarders, seem to travel very fast indeed.

Also, if a parachute had strong braking effect, surely you would lose balance and fall, which is sometimes the quickest way to stop, but not where it is steep, and would decrease control. While you are on your feet you have the best chance of steering and braking under control, provided you are skiing within your skill level. Maybe it could also get entangled with someone traversing behind you.

Has anyone actually tried releasing a parachute behind a skier? Seems to make more sense for boarders as they are often travelling straighter.

It would be a pity to discourage this research into safety, but at first sight it seems hard to see how it might work.

Some major accidents, like the German minister who killed a woman last season, involve emerging too fast from a side road on the piste. For slower skiers like me, it is useful to know if someone who is not really in control is trying to overtake me. In this situation someone went into me from behind while I was travelling in a straight line. I try to look round before a turn. If someone is trying to pass who is not under control I keep well out of their way, and often stop to let them pass. If I look round and see a good skier about to pass, I just carry on and let them get on with it. So for me, a way so seeing what is going behind would be a help.

There are times when skis cross, or hit something untoward under the snow, and I fall. There are times this even happens to experts. Maybe in this situation, on a steep slope, a parachute would be a good idea?

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 16:35:49 GMT

Isn't there also a possibility of the parachute deployment causing veering or lifting of the person which could move them into a position of more severe danger. So, the initial collision is avoided but a greater hazard is created.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 17:04:17 GMT

I'd say the time frame from that "oh sh*t" moment to crashing is generally about 1 second, if not less. I generally relax when I feel myself go, thus minimising risk of injury.

On motorbikes, you can get jackets that inflate upon impact, although they're very expensive, and once deployed, the jacket is useless. Some you can plug into the bike, which monitors the speed, and thus would only inflate at crashes over a certain speed.

Not sure a parachute would help..

You could go on youtube and watch some ski crash clips to see how people fall?

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 17:23:37 GMT

Parachute? Are you kidding me?????

As an experienced skydiver i can tell you that the deployment time of a chute is always going to be too long to be useful. Couple that with reaction times of the skier in actually activating the chute and you have a non starter im afraid.

1 second deployment? That sounds way off....How are you deploying? pilot chute? springs? some kind of rocket charge????? I really can't see it as you still have to rely on forward speed to fill the canopy.

I think that you would be better looking towards the front of the skier....maybe an airbag type of thing.

Sorry to be so negative, i do applaud you in trying to improve safety.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 17:25:56 GMT

This just all seems like a lost cause to me buddy, sorry. Hope it all goes well for you.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 17:40:42 GMT

There are still big problems with airlines in Europe accepting Avalanche Airbag Rucksacks, even though they are listed as safe in the IATA regs. I can see a charge deployed chute having all sorts of problems for the ski charter industry and their carriage restrictions :shock:

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:00:43 GMT

Maybe he is on to a looser but they said electricity would never catch on and the Write brothers were on to a looser. How many of you have the knowledge to rule it out completely, after all the ejector seat in a fighter jet deploys in less then a second.

Give the guy a break and answer his questions and let him do his research, it is not a business idea it is a collage project

The only time I ever crashed and had any significant time to realise I was going to crash was a couple of seconds at the most. Most of the time it comes as a surprise, I am trying to avoid someone's mistake or my own, but usually i am tumbling before i realise it

Maybe you should approach some extreme skiers where such a device might be more use. There are people who combine skiing with parachuting

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:11:44 GMT

mark203 wrote:Maybe he is on to a looser but they said electricity would never catch on and the Write brothers were on to a looser. How many of you have the knowledge to rule it out completely, after all the ejector seat in a fighter jet deploys in less then a second.

Give the guy a break and answer his questions and let him do his research, it is not a business idea it is a collage project

The only time I ever crashed and had any significant time to realise I was going to crash was a couple of seconds at the most. Most of the time it comes as a surprise, I am trying to avoid someone's mistake or my own, but usually i am tumbling before i realise it

Maybe you should approach some extreme skiers where such a device might be more use. There are people who combine skiing with parachuting

I agree Mark, give the guy a break ....... my concerns are when we are taught to ski they do not cover awareness and I think it plays a hell of a big part in avoiding accidents, when I ski with Little W I am
Always on her case about looking over her shoulder and being aware of her surroundings, looking out for trouble.
It should taught at ski school but I see no evidence of this.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:18:21 GMT

I was taught to look over my shoulder on the dry ski slop in Rossandale but when I took lessons in Livigno the instructor kept telling me not to worry about people coming behind me, it is there problem I was told.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:23:51 GMT

Mark, Ian.

The original post did state "Any views you have on the project that you would like to share would also be very helpful and valuable"
I dont think anyone here would want to deliberately slate this guys hard work. I commend him for it.....but my view is that it cannot possibly be 'feasible' and he asked for our views.

Mark....Ejector seat?? Com'on mate, lets be serious. They are serious pieces of hardware with serious weight and serious explosive capability. Comparing them to a ski parachute is plain silly.
Even so, the ejector seats ejection time is for the seat to be clear of the aircraft and not the inflation of the chute. The inflation of the canopy still quite slow compared to that.

Ian, i agree....awareness is the thing. If you are 'aware' then you are probably going to have time to react and to avoid problems. If you are unaware then a chute is simply no use.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:25:36 GMT

I think a parachute could be very useful for when you fall on your back on a steep slope and you can't stop. This happened to me last week, and I have no idea about how it happened. Suddenly I was on my back with my skis and legs in the air and hurtling down a steep slope. I was afraid to try putting my legs down in case I twisted my leg and ditto for my arms. Eventually I came to a stop totally unharmed and still with my skis on.

I also saw someone else hurtling down an extremely steep off piste mogul slope on their back (from the chair lift) and they were clearly totally unable to stop and they went a very long way like that and were still in fact moving when they went out of sight.

Either of us could have hit someone else and caused a serious collison. A parachute breaking system of some sort would have been great.

Ally

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:26:00 GMT

mark203 wrote:not to worry about people coming behind me, it is there problem I was told.

Which will become your problem when you are lying in a hospital bed after they have wiped you out.

I look at skiing a bit like driving....i check all my mirrors and blind spots 8)

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:26:24 GMT

mark203 wrote:I was taught to look over my shoulder on the dry ski slop in Rossandale but when I took lessons in Livigno the instructor kept telling me not to worry about people coming behind me, it is there problem I was told.

What the Instructor said was correct you are supposed to give way from above, but the stupid part of the statement is that it is also the direction you will get hit from ,when I spot idiots I have been known to just pull over to the side of the piste and let them go 8)
Did you enjoy Livigno 8)

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:36:23 GMT

AllyG wrote:I think a parachute could be very useful for when you fall on your back on a steep slope and you can't stop. This happened to me last week, and I have no idea about how it happened. Suddenly I was on my back with my skis and legs in the air and hurtling down a steep slope. I was afraid to try putting my legs down in case I twisted my leg and ditto for my arms. Eventually I came to a stop totally unharmed and still with my skis on.

I also saw someone else hurtling down an extremely steep off piste mogul slope on their back (from the chair lift) and they were clearly totally unable to stop and they went a very long way like that and were still in fact moving when they went out of sight.

Either of us could have hit someone else and caused a serious collison. A parachute breaking system of some sort would have been great.

Ally

Ally,

I kinda agree that a breaking system for such a senario would be great but a chute wouldn't inflate. It needs lots of clean fast air to do that, i think you would just end up dragging a pile of washing behind you . I guess you would need something like an ice axe and use it like climbers do, roll over and dig it in.
Also if you are hurtling down a slope on your back how would a chute deploy??

I have some decent experience of parachutes and although they are simple devices you do need certain criteria to be fulfilled for a successful deployment.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:40:42 GMT

Snapzz,
Design me a decent breaking system then, please, and I will test it for you next time I'm ski-ing. It was a very strange sensation totally being unable to stop, and I don't think I'd have been able to use an ice axe - some sort of anchor might have been better ?

Ally

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:43:45 GMT

There is a proven self arrest technique which has been in existence for many years. It is routinely taught to skiers who take higher level and off piste instruction.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:45:10 GMT

Snapzzz wrote:Mark, Ian.

The original post did state "Any views you have on the project that you would like to share would also be very helpful and valuable"
I dont think anyone here would want to deliberately slate this guys hard work. I commend him for it.....but my view is that it cannot possibly be 'feasible' and he asked for our views.

Mark....Ejector seat?? Com'on mate, lets be serious. They are serious pieces of hardware with serious weight and serious explosive capability. Comparing them to a ski parachute is plain silly.
Even so, the ejector seats ejection time is for the seat to be clear of the aircraft and not the inflation of the chute. The inflation of the canopy still quite slow compared to that.

Ian, i agree....awareness is the thing. If you are 'aware' then you are probably going to have time to react and to avoid problems. If you are unaware then a chute is simply no use.

But that is my point it can be taught, and lets be honest it could cave your life 8)

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:46:29 GMT

bandit wrote:There is a proven self arrest technique which has been in existence for many years. It is routinely taught to skiers who take higher level and off piste instruction.

And it is?

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:46:41 GMT

AllyG wrote:Snapzz,
Design me a decent breaking system then, please, and I will test it for you next time I'm ski-ing. It was a very strange sensation totally being unable to stop, and I don't think I'd have been able to use an ice axe - some sort of anchor might have been better ?

Ally

I couldn't possibly design one! I wouldn't know where to start.
An ice axe although ideal is simply not do-able either....imagine falling on one! ouch.
My guess is that cleverer minds than us have pondered this issue for years and cannot find an answer which is why we dont see them on the slopes.
I am not trying to pour negativity on a valuable crusade but a chute just cannot work, for may reasons.

I think you would have to look a the kit you carry such as your poles and try to use them to help.
Maybe you spring load pole tips with long spikes like a medieval mace that you could dig in the snow. I dont really know. Sorry.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:48:44 GMT

Peter
You're onto a hiding for nothing with this idea, enjoy skiing for what it is, I for one don't want parachutes introduced into a sport in which the risks are already well managed.
Helmets, body armour, back protectors & bobble hats to name a few, adding a parachute to the list is just not on.
Sorry for being so negative.

Finn

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:49:02 GMT

Ian Wickham wrote:
it can be taught, and lets be honest it could save your life 8)

Agreed.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:52:16 GMT

Yes OK get the point but he also asked for data, everyone just gave out there views

Snapzzz wrote:

Comparing them to a ski parachute is plain silly.

Well maybe it is, point was that it is possible even though it is not feasible. Well OK it is not possible I guess

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:52:38 GMT

AllyG wrote:

bandit wrote:There is a proven self arrest technique which has been in existence for many years. It is routinely taught to skiers who take higher level and off piste instruction.

And it is?

Finger nails

Trencher

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:54:09 GMT

How about going the other way and introducing a jet pack.

I've been watching road runner :)

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:54:16 GMT

It's why classical guitarist very seldom slide over cliffs.

Trencher

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 18:56:17 GMT

AllyG wrote:

bandit wrote:There is a proven self arrest technique which has been in existence for many years. It is routinely taught to skiers who take higher level and off piste instruction.

And it is?

You need to turn yourself over to face the slope. Then do a press up. As you are now presenting less sliding surface to the snow, you will slow down.

If you are not strong enough to hold the press up, go up onto your elbows and dig your boot toes in. If your skis are still on, get them below you as they have a braking action with the edges.

No parachute or fancy gadgets needed as they would probably get in the way and cause you injury.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 19:10:19 GMT

Thanks Bandit :D
I was actually afraid to try digging my skis into the snow, in case they didn't come off and I broke my ankle. I remembered someone wrote on here once about how skis only come off if the pressure is applied in the right direction, and I wasn't at all sure that they'd come off. I seemed to be going very fast, and my instructor was no help at all - I shouted that I'd fallen over and he just got out of the way.

Maybe I need to practise this standard technique of yours in case it happens to me again and I don't have my skis on.

Ally

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 19:19:40 GMT

Hi,

The reaction time is zero.

If there was a reaction time, there wouldn't be an accident.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 20:45:34 GMT

Wow, this is interesting. It's the same argument as air bags and avalungs in my opinion. At an applied but exceptionally rare occasion they may be of use, but 99.99999% of times simply useless and expensive. Even another gadget to give people confidence they don't deserve to act upon.

I am actually considering an Avalung after this weekends snowboarding, only because I found myself traversing to a closed and unpisted black run in Engelberg with a level 3 avalanch warning in place and loving it so much I did it again. There was a 10ft wall of snow cut into the traverse and evidence of 3 slides above. I understood the risk and took it, but had I an extra margin of safety I'd have used it. Difference here is that is a preventative measure not a corrective one. Correction depends on reaction, and that is the point of the OP. I don't think there is enough time in most cases. If there is, skill is likely a better option. For those without skill, education is the far better option.

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 21:06:16 GMT

Tino, I went skiing with someone, who'd put his Avalung on underneath his jacket :shock: I did mentiion it, and he moved it )

If you are thinking Avalung, then it's time to think about a Transciever as well. It's all well and good to be able to breathe whilst under avvy debris, but how will anyone know where to start digging?

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 21:12:49 GMT

bandit wrote:Tino, I went skiing with someone, who'd put his Avalung on underneath his jacket :shock: I did mentiion it, and he moved it )

If you are thinking Avalung, then it's time to think about a Transciever as well. It's all well and good to be able to breathe whilst under avvy debris, but how will anyone know where to start digging?

you are totally right of course, and I'm thinking of going whole hog on the avalanche safety. But as a predominantly solo rider the benefit it questionable for most forms of safety. Need some mates ;)

on the positive side, Engelberg after a fall of snow is the best place I have EVER snowboarded. If you like off piste it is heaven, just like the marketing claims. Never had so much fun standing up :)

Re:Investigation into Reaction Time in Skiing Accidents

Mon, 22 Feb 2010 23:08:50 GMT

I'm still trying to work out if the OP is interested in our views on reaction time, or just his ridiculous idea of a parachute for skiers?

If you want to measure reaction time, you cant. Its in someones head, and everyone is different.

Putting a parachute on a skier will either knock them over, take them somewhere they dont want to go, or take another skier out with all the gear coming out of the other persons backpack.

Avoiding accidents is impossible. We can all claim to have done well on skis or in our cars, but it only takes some idiot a fraction of a second and youre dust. You can be sensible and vigilant, and put a lot of faith in your fellow skiers as well.

But seriously, a parachute?

Purrrr leeeeeez.

Re:Investigation into Reaction Time in Skiing Accidents

Tue, 23 Feb 2010 00:35:46 GMT

This project seems to be one where a solution has been proposed, without the problem being adequately defined. That is entirely opposite to how a manufacturer would operate.

Even assuming the OP's proposal, there is no definition of "reaction time". You have to define the two events between which the reaction time is to be measured.

As skiers, we are all aware of the many different ways that accidents can occur. Sometimes, the reaction time is zero, you have been wiped out. On other occasions, there is suffiecient time to shout something like, " Ooooouuur, fecme, shheeeeeeeet, blady, blady, Moooouuuuuuuumeeeee."

So, say seven seconds.

That would seem to be a starter for Bandit's solution. Or possibly, Trenchers. As a definite NON-classical guitar/banjo player, I would have to have a go for Bandit's way.

Damn, does that mean, I have to add press-ups to the exercise routine?

Re:Investigation into Reaction Time in Skiing Accidents

Tue, 23 Feb 2010 09:10:27 GMT

5 seconds sounds too long for most accidents.
I would have thought there would be a lot of existing info from motoring accidents that would suggest that the time from the awareness of impending accident to accident is generally a lot less than 5 seconds. You can't meake an exact leap to skiing but reaction times, stopping distances, speed of chute depolyment to effective decelleration are largely calculable.

I guess the only likely role for a parachute would be if you were to ski off a cliff. (Or if you are trying to ski down Everest when the chute is used to limit speed on extreme steeps & reduced air resistance)

Most accidents happen because people aren't aware - most of us given 5 seconds could probably stop or scrub off a lot of speed sufficient to avoid an accident.

Re:Investigation into Reaction Time in Skiing Accidents

Tue, 23 Feb 2010 14:24:52 GMT

Ok guys thanks for your opinions but it seems like this has spiralled out of control
a little bit.

I am doing a Masters degree in Aeronautical Engineering, and the work I have done up to this point has foundations of work from leaders in the field of aerodynamics. The feasibility of the idea will be the result of my extensive research into all aspects of the subject, so although I appreciate all of your views and involvement (even though some of you dont seem to give it a slight chance!) I don't want this to get too off topic.

I am not saying that this idea will help everyone in every accident, but it may turn out that it is only feasible for certain ski conditions, for example downhill where the speeds are high and it is possible to get air (like Paerson in the Olympics).

I'm glad I've started a healthy discussion, but I don't want it to get too off topic so I'm primarily looking for skiers out there who have been in accidents and may have some idea as to how long they have before
realisation and the accident.

Thanks!

Peter

P.S Don't focus on the 5 secs, it was only meant to be an example!

Re:Investigation into Reaction Time in Skiing Accidents

Tue, 23 Feb 2010 15:05:35 GMT

Regarding the OP,

Remember human reaction times are in the region of 300ms.(It is actually quite easy to measure, I've done it for a number of projects in the past) If you are very good this reaction might go down to 100ms, but at that level we are talking about sprinters who are also to a certain extent anticipating the gun. If you have a fall at speed this kind of reaction time is not enough to save you so there is certainly no time to deploy a parachute. The parachute also takes time and distance to extend the line and inflate. In the few miliseconds it takes you to hit the ground even a self releasing parachute will not achieve line stretch never mind inflation.

tino_11 wrote:Wow, this is interesting. It's the same argument as air bags and avalungs in my opinion. At an applied but exceptionally rare occasion they may be of use, but 99.99999% of times simply useless and expensive. Even another gadget to give people confidence they don't deserve to act upon.

I am actually considering an Avalung after this weekends snowboarding, only because I found myself traversing to a closed and unpisted black run in Engelberg with a level 3 avalanch warning in place and loving it so much I did it again. There was a 10ft wall of snow cut into the traverse and evidence of 3 slides above. I understood the risk and took it, but had I an extra margin of safety I'd have used it. Difference here is that is a preventative measure not a corrective one. Correction depends on reaction, and that is the point of the OP. I don't think there is enough time in most cases. If there is, skill is likely a better option. For those without skill, education is the far better option.

Tino you realise 4 people were killed in the German speaking part of Switzerland by avalanches this weekend. Two of the 4 might have been saved if they had transceivers on and switched on! (One was wearing one, but he never turned it on!!!) Off piste alone when the risk is considerable is just silly. There are motivations in Switzerland at the moment to try to make freeriding illegal. People like the guy who was buried for 17 hours a few weeks back when freeriding alone with no safety equipment play right into the hands of the people who want it made illegal. If this happens it potentially criminalises ski-touring and free riding for the people who take safety issues into account and have had training.

I'm with Bandit, a transceiver, shovel, probe, training(and going in a group) should be the first things on your list, then think about the Avalung or ABS. I am personally very close to buying an ABS backpack because these days the majority of my skiing/boarding is away from the marked runs.