Tragic avalanche news

Should I even ask which organization was involved, or should I just assume the most likely suspect?

Should I even ask which organization was involved, or should I just assume the most likely suspect?

backpackers.meetup.com/114/calendar/6803238/

Yea, after reading the description of the event posted by its organizer Camron they should never allow that guy to be an organizer again. Seems his "experience" is from hiking the Snow Lake trail in the summer and I would guess he has very little snow hiking experience himself. It also seems that his "beginner" members who came along were better prepared then he was, and it could very much have been because of them nobody was more seriously hurt, or killed.

Note the time that the avalanche bulletin was issued. 8:30 am Saturday morning. No doubt, the people involved in the avalanche incidents had already left for the mountains. Part of educating the public includes issuing warnings in a relevant time frame. The avalanche forecasts are issued too late in the morning. It is unlikely that most backcountry users check the avalanche forecast on the day of their trip. That said, it was quite clear several days in advance that a major snow/rain event was likely Saturday-Monday implying that backcountry travel was going to be quite hazardous.

Also note that the Avalanche Forecast issued Friday November 30 stated there would be an Avalanche Watch Sunday and Monday.

The search for the snowboarders was called off last night. Yesterday roughly 25 searchers were looking for signs and any pings from beacons in the many debris piles in the area. Several were from climax avalanches. Additionally, a ground team and a helicopter had a Recco detector. Dog teams were on standby at base should a sign be found. One theory is that they triggered an avy on Sunday and were buried, and then on Monday, another one came through to cover any signs.

One spec that we heard is that a beacon with fresh battteries sends out a signal for 200 hours at 70 degrees. We were curious how reliable that is, how the duration would change at 32 degrees, and after 200 hours, does it stop, or is it just really weak?

It may depend on the make, but I'll bet it just gets really weak, and probably not in a linear way.

Are there and does ski patrol have access to ultra sensitive 457kHz receivers? Seems something above and beyond a consumer-grade avi transceivers might help in this sort of scenario. Also, does anyone close to the rescue/recovery know if the Recco system was used in this incident? I know those can be mounted on a helicopter, and there is a good chance these guys had some kind of Recco patch on their gear somewhere. I know the Alpental patrol has one.

Now that the search has been called off, will SAR be releasing any more details regarding the precise areas they were looking in? More skiers are sure to enter that area this season, it might help to tell us to keep an eye out if we end up skiing there.

Re: long range 457 kHz stuff, I'd always assumed that rescue organizations might have them. I'd be interested to know if they don't.

Since the frequency's so low, any pointing accuracy would be pretty low. Without signal processing like what's in the most modern beacons, the best you'd probably be able to do with the simplest possible receiver would be ~600m accuracy from an airplane. That much might, however, be a big help to an operation like this.

Does the military have any bored electronic warfare folks that'd be interested in a project? The hardware on an RC-135 would likely be immediately up to the task, and it's possible that some of the EA-6Bs out of Whidbey could be able to pull it off. Some of the military's toys may possibly be able to sense things like metal ski poles, pack staves, shovels, probes, etc. under the snow, if they're able to use them.

Anyone know the spec'd minimum signal output power of a beacon? A simple energy argument suggests that it's bounded above by 15 mW, but I suspect it's much less. It's quite possible that a simple magnetic dipole antenna and a reasonable amplifier, perhaps powered by a car battery/inverter to get it into the backcountry, could ferret out the signal. I'd guess that a resourceful HAM operator would know whether or not it's possible, and if so, pull it off. Searching with such a setup would reduce to the time-honored induction method, once a signal is received. If it's possible, I bet some of the HAM folks would be stoked to try it out.

As for the transmission from a cold beacon, that'll probably depend heavily on the guts of the beacon. I could guess about things all day, but the right thing to do, if you know what beacons they were carrying, is to chat with the manufacturer.

Given the discharge curves for most batteries, I'd guess that, to first order, once they stop transmitting, they stop. In the end, it'll depend sensitively upon the electronic design of the beacon.

Events like this might encourage folks to switch to lithium batteries in their beacons - longer life, better cold weather performance, and lighter (woo!) than the standard batteries. I'm switching mine over soon.

Thanks again to the Search and Rescue folks. Your efforts are most definitely appreciated by the rest of us!

Edit: Gary - your spec numbers look to be correct. Check Wikipedia or here: www.girsberger-elektronik.ch/media/docum...n_standards_2000.pdf , or google avalanche beacon standard .