Tuesday, January 17, 2017

Avalanche Airbags and You

It was February of 2012, and three skiers were dead just outside of the Stevens Pass Ski Area in the Tunnel Creek drainage. Five people were initially caught in the backcountry avalanche. One of the survivors became wedged between two trees while snow rushed over him. The other survivor – Elyse Saugstad – deployed an avalanche airbag, which kept her near the surface of the snow and allowed rescuers to find her quickly.

Saugstad’s survival created a great deal of interest in avalanche airbags. Our shop at the American Alpine Institute began to receive almost daily inquiries about these potentially lifesaving tools. And now today, these devices are standard for ski patrollers and backcountry ski guides.

The BCA Float 42 is a single balloon pack
with 42-liters of space.

But what are they?

In essence an avalanche airbag is a regular backpack with one or more large balloons stowed in the top and the side. The idea is that if there is an avalanche, the skier can pull a ripcord and deploy the rapid inflation balloons almost immediately. And then in theory, these balloons will keep your body near the surface of a moving avalanche, allowing for an easier rescue.

There are many aspects that must be taken into account prior to the purchase of one of these systems. First, of course, there's affordability. Second, there's the difficulty of refilling the cartridge. Third, there's the question of how easy it is to stow and retrieve the trigger. And lastly, one's perception of a given brand and indeed, even one's loyalty to it.

Before making any purchasing decisions, you must look at the advantages and disadvantages of three main aspects of this system.

  1. What type of gas is being used to inflate the balloon chamber?
  2. How many balloons are being inflated?
  3. What type of mechanism is being used to trigger the deployment of the balloon(s)?
To decide what kind of gas (compressed air or nitrogen) is the most appropriate for you, first and foremost, you must think about where you are going to use your pack. Air temperatures and altitude may have an effect on cartridge performance and in effect, the speed by which the gas moves from the cartridge to the balloon(s). It appears that the compressed air works a little better at lower altitudes – like those found in the PNW – while nitrogen works a little bit better up high, like those found in Colorado.

One additional concern that should be mentioned is the difficulty that some have had taking these backpacks abroad. For some reason the TSA doesn't like weird cartridges of gas stashed inside backpacks on their planes...

North Face Avalanche Airbag Pack
Note that this is a two balloon system.

The terrain that you're skiing is another factor to take into account. If you’re skiing in a place where there are lots of sharp trees and branches, or in a place where there are a lot of sharp rocks, there is the possibility that you are going to puncture a balloon. Some systems employ a two balloon pack with two valves for two reasons -- first, in case one of the valves malfunctions; and second, in case one of the balloons is punctured after deployment. Some brands have worked hard to develop a configuration that provides more "floatability" by playing with the volume and spatial adjustability of the balloons...

If you are going to be using the pack as a recreationalist you may have different needs than a ski patroller or a guide. Why? Because each group has different needs. The recreationalist needs affordability and functionality with a simple pull. Professionals often use packs with mini-explosives that (according to the respective marketing departments) will guarantee deployment above and beyond the minimum standards. And lastly, a guide may want a remote control triggering mechanism in case one of his or her participants is in a slide, but fails to trigger the system.

Now the real trick of these packs is not that they might "save" you from an avalanche. Instead, it's that they might trick you into a false sense of security. The pack will give you a better chance if you're in a slide (about 16% overall or about a bit more than half of those who would have otherwise died in an avalanche), but it won't save you from drop-offs or trees or boulders or any number of other terrible things that could happen to you if you're involved in a slide. The best tool that you have to avoid an avalanche is your own brain and your own ability to use it. If you haven't taken an avalanche course, then you're missing the key ingredient.

--Jason D. Martin

No comments: