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What, Really, You Should Do With Your Smartphone in the Backcountry

Smartphones: we all use them, all the time. And yes, even in the backcountry (Instagram!). It'd be too simplistic and even unsafe to just tell people not to bring their phones at all when they head out of bounds, because while their signal does interfere with that of an avalanche beacon within a certain range, they become incredibly useful in the event of an emergency in order to communicate with the outside world.

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Johnny Bresette, guide and co-owner of Alaska Powder Descents, gives us the lowdown on how we should all operate with our smartphones in the backcountry, namely to turn them off anytime you're searching for a victim.

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Comments (10)

good information, but if you want people to be able to pay attention, maybe don’t shoot the video with all those people talking in the background.

    Definitely a good point, but it was a non-stop week and we were doing our best to grab guides to produce content in the short windows in which they were available. Definitely something we’ll work on improving for next year’s Safety Week, though!

if you set the iPhone in “airplane” mode it should completely disable all RF, so theoretically it should not interfere with the beacon’s RF.  has anyone tried to just set them in airplane mode to see if it messes with the beacon?

while you’re on the topic, shouldn’t people be turning off their two-way radios, such as FRS/GMRS?  what do patrollers do with their UHF or VHF radios when they’re wearing their beacons?  are beacons on the UHF or VHF spectrum?

Thank you for posting this segment, great detail to be aware of.

I noticed that Johnny Bresette put his cell phone in his upper left pocket right over where a beacon rests on the left waist or rib cage (within 5-10 cm of the beacon).  I would love to see technical outerwear companies understand this dilemma and start creating inner phone pockets on the right.  I have personally purchased a lycra waste band that I wear inside on the curve of my back to keep the phone away from the beacon and warm.

    That’s an interesting thought. I tend to put either my beacon or my phone in a pants pocket and the other by the chest, trying to keep that distance in mind at all times. I know Black Diamond’s outerwear all features a specific beacon pocket in the pants themselves, maybe partially with this in mind. But I feel like the pant/jacket separation is an easy way to avoid this.

      Most beacons have specific around the neck systems that sling diagonally across your chest.  The reason for this design is that the beacon rides in the most protected part of your body and for quick, secure deployment for searches.  I do not think in your pants pocket is what the beacon manufacturers had in mind. Black Diamond is a very respected manufacture of alpine/alpinist gear, are sure the pocket in the pants isn’t intended for the phone?  I still think a cozy pocket on the right side, in my otherwise well thought out, technical wear (for my phone) would be nice.

        I did visit Black Diamond’s website and checked out their pants, which look very nice and well designed.  I still think I will prefer to wear my beacon next to my heart but after reading both Ryan Dunfee’s and Wasatchbill’s comments I now want a foil lined cozy pock on my thigh for my phone.  A foil lined pocket on the right side of my coat would be extra nice as well.  Thanks for all the great information, thoughtful replies and suggestions.

Airplane mode is a good step, but it just turns off the cell, and GPS stays on. If you are not using a GPS app, then you can turn GPS off also.
There are also a number of shielding devices designed to protect yourself from the EMF radiation, or secure the phone from eavesdropping; and they obviously would also work to shield your beacon from the phone:
The following video shows how wrapping with simple aluminum foil can completely shield the phone also. This might be helpful if you need to place a rescue call, then quickly shield the phone to go into search mode, without taking the time to shut down the phone, and then power it up again if needed (without the expense of a “faraday cage bag”).
Here is some more data, although it seems a bit odd in places (why does a camera cause more interference than a cell phone?). I assume “small radio” is like a patroller’s two way radio, and they are low on the interference axis; with an effect at 0cm, but not 10cm.  My experience when patrolling with a radio was similar; it didn’t seem like a big issue as long as there was some separation.
Note that an ipod causes quite a bit of interference in these tests.

A friend working in the industry tested and explained the problem as follows.
It’s not only a problem with phones (no matter switched to airplane or not). Problems can also appear with radios or other electronic devises. They found out that close or direct contact with the beacon can interfere with the magnetic on/off switch which in some cases turned the beacon completely off.
Therefor the problem also exists in search-mode and NOT only in tracking-mode.
Reccomendation is to keep every devices 20cm away and shut off when tracking. And keep in mind that the 40 cm from your trouser to your chest might only be 10cm when burried…

Turning to airplane mode does little to help the source of the issue.  Most of the interference is being produced by the module that provides power to the cell phone.  Granted your phone may pull more power when connected to a network, but the notion that the interference is from the cell phone signal is false.  Unfortunately turning the phone off is the only fix.

For a professional rescuer who needs a radio and other electronic equipment turned on, there are techniques to cogently filter out false positives from the interference.  Those orgs should be practicing those techniques.