I've been wearing an Avalung II and Avalung backpack for years. Technically known as an artificial air pocket, the device has long been proven to prolong avalanche survival by preventing carbon dioxide displacement asphyxia. Last year, Black Diamond posted an internet report of a skier surviving a non-avalanche burial in a tree well using an Avalung.
However, avalanche airbag backpacks add one-step-prior level of protection. They lessen chance of burial by increasing your body size and flotation, thus improving your chance of staying at the top of sliding snow. This season, several companies offering airbag backpacks: Backcountry Access, Mammut, ABS, and Mystery Ranch. Compared to the Avalung, airbag packs are more expensive, weight more, and have more bulk. But they are coming down in price, size and weight and many have refillable gas canisters. So, airbag packs lessen risk of burial whereas the Avalung functions once you are buried--what to use this year?
--Christopher Van Tilburg, MD