The AviPack is designed for anyone traveling in avalanche terrain.
If a traveler or skier is caught in an avalanche, they simply pull the rip cord located on the right shoulder strap. The airbag inflates and rises to the surface of an avalanche taking the victim with it. This physical process is known as inverse grading, or inverse segregation. It happens when particles of different sizes are mixed in a laminar flow, as in an avalanche. Larger particles will tend to be separated from the smaller particles and rise to the surface (similar to shaking a can of brazil nuts).
The bright red color of the airbag enables companions and ski-patrollers to quickly locate the victim from up to ½ mile away.
The AviPack is constructed from 4 components: Pack, Activation System, Inflation System, and Gas Cylinder. The Pack holds all the WARY Airbag System components while providing pockets for the user to carry items such as probes, radios and extra clothing. It is also a structural component, keeping the inflated airbag attached to the user during an avalanche.
The Activation System takes input from the user and initiates the inflation process of the airbag. Pulling the activation handle allows a seal pin in the activator to move, releasing the gas.
The AviPack uses a DOT/TC approved Gas Cylinder containing approx. 63g of compressed air (at a pressure of 3000 psi) to inflate the airbag. Each cylinder can be reused, but must be recharged after each use.
After the contained gas in the cylinder is released, the Inflation System routes it through a high-pressure hose to a Venturi mounted on the airbag. Consisting of a jet and body, the Venturi uses the fast moving high-pressure gas from the cylinder to create a low pressure in the ambient air surrounding it. As the high pressure gas continues down the body of the Venturi it literally 'pulls' in ambient air, filling the airbag. By using the Venturi we are able to fill a 150 Liter airbag with approximately 50 Liters of compressed air.
Once the user is out of avalanche terrain, the airbag can be easily deflated and repacked into the AviPack by lifting a tab on the Venturi and depressing a valve.
The AviPack utilizes the principal of inverse segregation to keep the avalanche victim on the surface of the avalanche. In the simplest terms, inverse segregation is the likelihood that the largest objects by volume will stay on the top of a turbulent medium. The smaller objects can more easily fill in the small spaces as the materials in a turbulent flow mix and interact.
An avalanche is made up of billions and billions of grains of snow. The size of the particles is determined by many factors: slab hardness, size and class of avalanche, etc. Typically the grains of snow are broken into very fine particles. As these particles fall and tumble down the mountain they are constantly mixing and churning. During the turbulent slide gravity exerts an equal force on all of the particles in the avalanche. The smallest of the particles have less resistance to falling into the spaces that constantly open due to the chaotic motion. This action causes the smallest of the particles to inversely or reverse segregate.
So now you might ask yourself, "What can inverse segregation do for me"? A tenet of inverse segregation is that the largest objects will be separated to the top of the turbulent medium. So for snow riders caught in an avalanche this principal can be very useful.
The next question is then, "How can we use inverse segregation to stay on the surface of an avalanche"? An airbag is the best way to implement this principal.
When wearing an AviPack it is very important not to be concerned with activating the airbag. It can not harm you and will not interfere with your ability to ride out of the avalanche. The airbag is located behind your head and can easily be deflated after you are safely out of harms way. We do recommend leaving the airbag inflated until you are sure you are out of any other avalanche paths. Remember that if there has been one avalanche, a second or third could happen also.