Auto-Revert mode on your avalanche transceiver is important for rescuers in areas where there is a danger of secondary avalanches from hangfire and cornices above the debris. A cornice brake triggered this avalanche on the east face of Abundance outside Cooke City, MT. Photo: GNFAC.
By DArcy McLeish
One of the most dangerous times in an avalanche incident is right after someone gets buried by an avalanche. Working as a professional ski patroller, I can tell you that this is one of those times where the stress level is at its highest, your adrenaline is pumping, and your decision-making ability will be challenged. A worst-case scenario is the danger of a second avalanche coming down on the people scrambling to rescue an avalanche victim. This is why Auto-Revert mode on your avalanche transceiver becomes so important.
Picture this. You're out shredding in the backcountry and someone in your group goes for a ride in an avalanche. You watch as the slope rips out and you make sure to keep your eyes on them as long as you can, hoping they don't get buried or they manage to ski out of it. But they don't. With their last-seen-point clear, you and your group begin a beacon search.
But is racing to the avalanche debris to begin your avalanche transceiver search the first thing you need to do? Unfortunately, it's not.
As rescuers, it's critical to make sure the scene is safe before beginning an avalanche search and rescue. Is there hangfire (lingering avalanche hazard) leftover that might release or have to be dealt with? Are there cornice dangers or another slope that might rip out above you? Is it still snowing and reloading the slopes above? Are you and your friends in danger of getting buried by a second slide while you search?
None of these things are easy to see clearly when someone you know is sitting below you in a life-threatening situation. But the risk of another avalanche coming down on searchers is all too often very real and very possible. There have been several documented incidents where searchers have gotten caught in a secondary slide and, in some cases, it has proven fatal. Enter Auto-Revert mode on your avalanche transceiver. Most transceivers nowadays have an Auto-Revert option where the transceiver will automatically switch back to transmit (send) after a certain amount of time in search mode. The theory behind this is that if you get caught in a slide while in search mode, your transceiver is searching rather than sending out a signal eliminating the ability for someone to locate you. Not good. Auto-Reverting back to transmit mitigates that risk.
How to Use Auto-Revert Mode Video
Auto-Revert mode is important when having to perform a search in a dangerous area where a second avalanche is still possible. If your Tracker3 is in auto-revert and you are in search mode, it will revert back to transmit if it hasn't moved for more than one minute. Even if you are moving, it will still revert back to transmit after five minutes. This means that if you get buried while searching, but you're struggling to get an air pocket, the Tracker3s motion sensor won't prevent it from eventually going back to transmit.
BCAs Tracker3 avalanche transceiver is the only transceiver on the market that offers this redundancy. Some transceivers have their Auto-Revert modes hard-wired in: what that means is you choose, when setting up your beacon, to enable or disable Auto-Revert on your beacon, but the downside to this is you cant quickly enable or disable this option in the field. One thing that is worth noting is that even nowadays, there are a few beacons out there that don't offer any auto-revert mode at all.
BCA Tracker3 is set up so that when it is about to switch back to transmit, there is a warning beep before it happens. An alarm will sound 30 seconds before the unit returns to transmit mode. The alarm gives a rescuer the option to not switch back if they are sure there is no danger and its safe to continue the search. During this period, reverting to transmit can be avoided by pressing the Options button or moving the mode switch before the 30-second warning period has elapsed.
The idea of a motion sensor is a clever one and provides an opportunity for a searcher who gets bagged to have their beacon turn back to sending a signal very quickly, without having to wait 5 minutes or in some cases, up to 8 minutes, depending on the manufacturer. That's a long time. But the key with the Tracker3 is you get both a timer of 5 minutes and the motion-sensing system as well. So if there is no movement during a search, after 30 seconds of detecting no movement it will beep to warn you, but if there is still no movement, after another 30 seconds it will switch back to transmit. That's critically important, especially for professionals who are responding to searches on a regular basis and are potentially under a higher risk for a secondary avalanche. In any avalanche rescue scenario, time is never your friend.
Auto-Revert back to transmit isn't cut and dried: there can be problems associated with a beacon automatically switching back to transmit. During a search, especially when there are multiple searchers, if one transceiver switches itself back to send it can confuse the entire search. All of a sudden, there is a new signal in the debris and searchers will pick up that signal and potentially lose precious time searching for someone who isn't buried at all, but just has their beacon sending a signal. This is what BCA calls renegade signals and it can be a huge problem. In fact, its a much more prevalent and vexing problem than having to find multiple buried victims (at least those transmitters aren't moving around). Renegade signals were partially responsible for an unsuccessful transceiver search several years ago in Oregon, leading to a fatality.
This is why all Tracker transceivers are programmed so that Auto-Revert is not activated unless the user turns it on each time they turn on their Tracker. If you know enough to perform this procedure (see video above), that means you'll know what's happening when the warning alarm comes on and you can take the necessary steps to prevent interrupting a search. But if you're not familiar with the Auto-Revert function (and warning alarm), then your transceiver will most likely begin transmitting a renegade signal without you knowing it. With all other transceivers, auto-revert is the default setting, meaning that dangerous renegade signals are more likely.
Avalanche rescue is involved: you must know the basics of beacon searching, probing and shoveling. Then there are the more subtle skills that delve into things like human factors: how we approach terrain, how we move through the mountains, and how our decisions are made in group settings. Finally, there are the decisions we have to make when something does go wrong, and believe me, under huge stress, trying to think gets extremely difficult. Having equipment that is developed to engineer out as much risk as possible contributes to making better decisions and makes for more of what we all want pleasant days in the backcountry with good friends and deep snow. So do yourself a favor and learn all those skills. Learn about avalanche rescue and learn the ins and outs of your equipment.
So when you're shopping for a new avalanche transceiver, look at the detailed functions of the unit you're considering. BCA goes out of its way to make and develop products for real-world scenarios and applications, all tried and tested in the same places you want to go.
DArcy McLeish @thesurlycitizen is a writer, copywriter, professional ski patroller, rope access technician, mountain rescue specialist and contributor to @Snowbrains, an online media portal featuring skiing, snowboarding, weather and snow reports worldwide.