This weekend's tragic fatality near Gin Peak may have revealed a possible weakness with Pieps DSP pro and sport transceivers. The victim's beacon was in search mode.

Some people have noted that the transceiver's lock switch can easily get pressed in by the pressure from the pouch buckle, allowing the beacon to either switch off or go into search mode, with only a little pressure.

Here's a video describing the issue: https://www.youtube.com/watch?v=dMtrMYsMWoY&feature=youtu.be

Two possible solutions are to either carry the beacon with the screen facing the inside, or to tighten the strap holding in the transceiver as much as possible.

Pieps has been made aware of the incident and is looking into it.

Thanks for posting this Chris.  A very sad accident.  It does drive home the message that our transceivers, shovels, probes, and airbags are backup systems, not the first line of defense.

Avalanche.ca has a brief summary in their incident database.  States that the transceiver was in a hip pocket and the avalanche airbag, while deployed, sustained significant damage.  It sounds like they were skiing the slope one at a time, a good thing.

In the comments for the video, the poster says he has had the slider shift even with the screen facing towards the body.

I actually did some testing on our 2 Pieps DSP Pro beacons, purchased this year, to see if I could replicate the issue shown in the video. I was not fully able to do so, but was able to do something that was perhaps more concerning, as it can't be fixed just by reefing on that strap.

Matty's video shows pressure through the pouch unlocking the slider and wiggling of the beacon within the pouch sliding the unlocked slider. I was able to confirm that yes, sufficient pressure on the pouch does push in the unlock button, regardless of whether the screen is out or in. (though it is definitely easier to do it screen-out) Our two beacons seem to (at least for now) have tight sliders, though, and no amount of wiggling caused them to move.

However, because of the current (IMO problematic) design of the pouch, part of the slider is exposed. This means that in theory, if the unlock button gets pressed in, the slider can be moved without removing the beacon from the pouch. So I decided to test and see if any real-world scenario could actually cause this, especially if one takes the precaution of wearing the beacon screen-in.

Verdict: yes.

If I move the beacon very slightly upward from its normal left-kidney resting place, I can get it to press against my left lower ribs.

If I push moderately hard (even with an open palm - not talking pinpoint pressure) I can put enough pressure between the beacon and my lower ribs to push the unlock button.

If the unlock button is pushed, one hit to the exposed slider can rather easily put the beacon into search mode. (turning it off in this position is considerably more difficult but theoretically possible)

I tested this both with the beacon worn on the outside and with it covered by a thick midlayer plus a hardshell. In both cases, the combination of a beacon against the ribs, moderate pressure, and a single strong tap in the right place were enough to change beacon modes.

I determined that as long as the beacon is worn screen-in, the most likely failure mode by far is for it to get put into search. Accordingly, I took the beacons to Comor Sports in Kits to have them turn on the auto revert to transmit mode, which is off by default on Pieps beacons. With that mode turned on, I'm once again fairly comfortable with these beacons but still feel that the pouch needs a redesign to ensure the slider is fully covered.

I'm hoping to find some time during the weekend to make a video of this.

Thank you Marissa. You should post your observations to the South Coast Touring Facebook group. There's a lengthy discussion there on this topic there, and your observations are pretty comprehensive. I know that some of the group members have contacted Pieps, and they have responded, saying they are urgently looking into this and they will followup. No ETA on a response at this time.

One interim solution seems to be to get the beacon programmed to enabled search to send, which automatically reverts from search to send mode after a certain period of time has passed. This programming can only be done by an authorized Pieps service center. And while search to send is helpful, every additional minute buried is critical, so this isn't a permanent solution. Beacons switching back to send mode can also cause dangerous confusion in a rescue scenario.

In the meantime, Pieps DSP owners should be very aware of this potential failure mode.

Hey Chris,

My observations are buried somewhere in the comments on South Coast Touring - was really wanting to get some video before posting them as their own thing, as I think seeing what can happen and how easily really kind of drives the point home.

I agree that getting auto revert turned on isn't a solution, especially for DSP Sport owners, as the way the beacons handle the auto revert is rather different between the Sport and the Pro. With the Pro, it's movement-based: 30s without movement and it starts making a really annoying noise; 30 more seconds without movement and it starts transmitting. With the Sport, it's purely a timer thing - 3m30s until annoying noise, 30 more seconds until transmitting. In my opinion, that makes the Sport both more likely to enter transmit mode during a rescue without being noticed (if you are doing something so intensely you don't notice the horrible noise you are probably moving around enough to tell the Pro not to transmit) and less useful in case of an accidental slip into search mode (3 minutes is a long time).

After a 3 day Spearhead trip this weekend found my beacon in the OFF position. Upon looking closer discovered the locking latch is cracked and not doing anything. The beacon was in the pouch exactly how it supposed to be. It was not dropped or otherwise mishandled. 

http://imgur.com/a/2PuM6