In reply to George Ormerod:
Its no replacement for companion rescue but is an addition to it when folk are not rescuable by companion rescue, especially as many skiers and mountaineers do not follow the ethos of companion rescue, not even carrying a shovel. There are dozens of RECCO equipped search and rescue in the alps and North America including helicopter detectors. Reflectors are passive and relatively cheap. RECCO search has saved many lives and perhaps many rescuers also by finding folk fast and limiting exposure of the rescuer in avalanche terrain. Its also endorsed by ICAR. Many folk are found alive from 30+ burials especially deep burials. The issue for them at times greater than 30m is firstly and immediately 2 aspects of triple H syndrome Hypoxia and Hypercapnia but also more ambiguously Hypothermia which can be either protective with rapid cooling or less so with slow cooling especially with good modern clothing. Robert Burnett who was dug out alive after 22 hours in the Cairngorms had poor clothing by modern standards and cooled quickly. Being found is better than not being found. Statements like "nearly everyone" is dead at 30m is not particularly helpful. Nearly everyone getting to hospital from pre hospital cardiac arrest doesn't survive to discharge. Yet we still have public access defibs, advocate CPR to buy time, pads on and shock them as many do survive and go on to live good lives. Having attended over 37 fatal avalanche accidents some multiple I am pretty pleased with 2 others that survived being avalanched of which I am one.