Originally Posted by avalanchesafety 
I explained in my last e-mail about the freeze up and tree hugging. Adressing the issue of limited head movement and visibility, YES the airbag does limit your head movement (quite a lot in fact) but i do not think this is a bad thing if your are being ragdolled down the mountainside. It also does restrict some lateral vision, however you still have good forward vision and your arms are free to move around and hang on to the bars for dear life.
Like the idea of slicing with a knife for extra airspace. - but is that not a bit far fetched??? Remember from my avalanche course that most slides set up like concrete withing a few seconds of slide comin to a stop - if you are buried good look trying to free your knife out of your inside jacket pocket. How londg do they take to slowly deflate. Are they CSA approved??
Just to clarify - With a sledding helmet on if your head is pushed down and helmet likely rolled forward a little - you have no vision. Am I missing something here???