I've seen a few cases of sudden belt slippage when arriving in the hover in loose dry snow (read - - big nasty white snowball ! )
This not the time you need control issues, horns, etc as you are searching for the ground in a white-out ! I have also seen a few broken belts, plus a lot of burned - glazed ones.
I work with a 100% Bell company now(
), but my past employer used to have a spare belt fastened around the drive-shaft of each 350, so the complete dis-assembly of the drive system was not required to change the belt -- once anyway.