Avalanche transceiver: basics – training required

All avalanche transceivers transmit on one internationally standardised frequency of 457 kHz. That is why devices from different manufacturers can find each other – wherever the group comes from. The signal passes through snow, but only over a limited distance, which is why in an emergency you approach the avalanche debris systematically.

The search runs in phases that are trained in detail on courses: first you look for an initial signal. Then you follow the direction and distance shown by the device coarsely. Close to the person, the location is narrowed down finely. Finally you probe until you hit the person, and dig them out.

Modern devices show direction and distance, but the signal follows curved lines rather than a straight route. That is one reason why you have to practise using your own device under realistic conditions instead of relying on the display alone.

A transceiver only helps if everyone in the group wears one, it is switched on and it works. Someone alone gets nothing from it in an emergency: there is nobody to search. That is why transceiver, shovel and probe are part of the basic kit of every group member.

The device is worn in its harness under the outer layer of clothing, not in the pack, because a pack can be torn off the body in an avalanche. Before every trip the group does a check: battery level, transmitting and receiving of all devices, as learned on the course. On the way the device stays on transmit.

Keep the transceiver away from other electronics such as phones, radios or cameras. These devices can interfere with the signal, especially in search mode. The necessary distances are given in the manufacturer's instructions.

The most important avalanche safety happens before the avalanche: read the avalanche bulletin, assess the terrain and, when in doubt, give up or turn back. A transceiver is the last rescue measure, not the first. Anyone who feels safer because of the device and therefore takes more risks makes things more dangerous, not safer.

If someone is buried, every minute counts. A buried person's chances fall quickly the longer they lie under the snow. That is why rescue is alerted at once – local emergency number, 112 in the EU – if possible by one person while the others start searching immediately. Waiting for professional rescuers without searching yourselves costs the decisive time.

Also watch your own safety during the search: could another avalanche come down? This entry does not replace a course and gives no first aid instructions; both are learned from trained professionals.

The starting point is an avalanche course, as offered by alpine clubs, mountain schools and guides. There you learn not only the transceiver search but also avalanche awareness, trip planning and the right sequence of companion rescue.

After that: practise regularly, ideally several times per season. Many ski areas and clubs have practice fields with transmitters buried in the snow. Also practise harder scenarios such as multiple burials, and practise probing and shovelling – digging out often takes longest and is physically very hard work.

Get to know your own device well: how do you switch quickly from transmit to search, even with gloves on? How does it show several signals? And how do you switch it back to transmit if a second avalanche comes down?

The avalanche emergency kit always includes three things: transceiver, shovel and probe. The transceiver finds the approximate spot, the probe shows the exact position and depth, and the shovel frees the person. If one is missing, valuable time is lost in an emergency.

Avalanche airbags and other systems can complement the kit. But they replace neither transceiver, shovel and probe nor training – and above all not careful choice of terrain.

Look after your device: check batteries before the season and before every trip, use the batteries the manufacturer recommends and take them out over the summer if the manufacturer advises it. Many manufacturers also offer software updates or checks.