Heli-Bombing, and Other NewsPosted: December 7, 2012
Ok, let’s get this thing going again. Sorry for the lack of posts over the last few weeks, the Lowdown turned into more of a ‘Slowdown’. No more – I’m back, and will be here to take you through another great season at Lake Louise!
Skiers already know that we’ve been enjoying an exceptional start to the season. A big November (though not as big as last year) led to a quick ramp-up of terrain and lift openings, and tracks quickly appeared in places that sometimes don’t open until Christmas or later. During the Men’s World Cup races, conditions were about as good as they get, with a perfect blend of new powder, sunny skies, and warm temperatures. I spent the morning roaming the upper mountain and taking photos, and luckily ran into local boy Matt Sweet, who happily agreed to accompany me as a ski model for a few laps on Top of the World and Summit. Thanks Matty!
One of things that made the early November conditions so good was the way the snow arrived . I’ve posted before about a snow pack that is upside-down. This refers to when lighter, weaker snow is low to the ground, and heavier, denser snow lies over top. This sort of snow pack is common in this neck of the woods (the Rockies), and initially does not provide a good base. A metre of snow could still mean your skis are hitting the ground underneath, and it’s not until there’s been more traffic with its resulting skier compaction that any sort of base is formed.
This year, however, things are right-side up, which makes everybody happy, particularly those in the avalanche control department. Upside-down is also known as strong over weak, and this is the simplest way to describe a weak snow pack. Weaker layers underneath eventually fail when too much of a load is placed on top, whether that load is more snow, a skier, or both. A heavier, denser layer below makes a good foundation for a stable snow pack, not only in the form of a good base for skiing, but also as one that is more likely to stay in place over the course of a winter – and everybody’s happy.
Of course, it wouldn’t be the Rockies if there wasn’t some layer down there messing things up. We can thank November 6 for the one that’s been on people’s minds so far this winter – a rain event that resulted in a crust, which is a poor bonding surface for any snow piling up on top. We’ve seen numerous avalanches react on this layer, mostly the result of explosives but some naturals as well. It’s happening less these days however, and while the crust is still there and might still react under heavier loads, it’s slowly becoming less of a concern as control teams work the terrain and the ever-so-valuable skier compaction increases.
During the weekend of the Men’s World Cup races, control teams took advantage of the fact that a helicopter was parked right outside their front door and performed what is often a highlight of the winter for those in the avalanche control department – heli-bombing. At a few thousand dollars an hour to use a helicopter, people wonder if this is the most cost-effective way to perform control work. We don’t use it just because it happens to be parked at the resort. It just so happened that the week leading up to the Men’s races was a snowy one, resulting in a widespread load placed over the Nov. 6 crust. To cover all of this avalanche terrain would take days, whereas using a helicopter took a little over half-an-hour and completely removed staff from hazardous slopes. One of the targeted areas was Skoki Slides on the lower flanks of Mt. Redoubt, and while this area is inside the ski area leasehold, it is not close to lift-serviced terrain. These slopes loom over the supply trail to Skoki Lodge, and it would take the larger part of a day for crews to reach a suitable staging area for use of explosives. With the helicopter, it added a couple of minutes to the loop.
It’s hard to describe what it’s like being strapped into a seat in the back of a helicopter, next to a big hole where the door usually goes, and two bombs with lit fuses in your hands. Yes, it might be cool to pipe Ride of the Valkyries over the headsets, but they’re filled with constant communication between pilot and staff, as you would expect with live explosives in a helicopter.
Along with the pilot, a typical heli-bombing mission will involve three patrollers. Two in the back take care of assembling the shots (attaching igniters to fuses), lighting them, and handing them to the bomber, who throws them onto the slope. The whole operation is coordinated by the patroller sitting up front – in this case our Avalanche Forecaster – who guides the pilot along the predetermined route and instructs the bomber when to throw the shots. Often the crew will do a fly-by of the terrain about to be bombed, so the pilot and bomber have a clear picture of where each shot is going. Sometimes the targeted slope is obvious, but other times they’re less so, and when pinpoint accuracy is needed, the fly-by is a great way to make sure everybody is on the same page.
For control operations on the ground, patrollers communicate each step of the operation with each other. Radio calls for each shot include “igniter on”, “safety off”, “fuse is lit”, “shot in Swede’s” (or wherever they’re blasting), and “30 seconds” to let people know it’s time to cover their ears (fuses burn for two-and-a-half minutes). Keeping the pilot in the loop adds to the communication. From a helicopter, bombs are generally thrown in groups of three. The assembler will light three shots in quick succession once instructed by the patroller up front. The pilot will be informed when the first one is lit (so he knows there’s a lit bomb in his machine) and then when all three are lit, so accurate timing for all three can be maintained.
Some helicopters have hot mics, where the headset microphones are activated merely by voice, and leave the wearer’s hands free for other things. This was not the case in this helicopter, as each passenger had a button on the ceiling of the cabin they needed to press in order to speak. So that they could keep their hands where they needed to be, I was the one communicating to the pilot the status of lit fuses.
Our route that day began in the Lipalian Chutes near the top of Larch chair, and made it’s way over to the Skoki Slides, then along Richardson’s Ridge to end up at Upper North Cornice with a short side trip over to the lower slopes, or fans, of Whitehorn II. Of all the shots thrown, only those in the Lipalian Chutes (1 & 3) resulted in avalanches, as shown in the photo below:
Since that mission, crews have been hard at work getting more terrain open. Yesterday saw the gates crack for Big 7 for the first time, and earlier today skiers got the first tracks of the season in ER3. Things are looking up for a great Christmas, but there’s no reason to wait until then to enjoy an incredible start to the season!
Fun fact: After typing in “heli-bombing”, WordPress identifies it as a spelling mistake. One of the alternatives it suggests is “deli-bombing”. Go figure…