Avalanche Airbag Backpack Buying Guide
Widely regarded as the fourth piece of must-have backcountry safety equipment, avalanche airbags have been shown to save lives by preventing burial when caught in an avalanche.
Airbag systems are built into backpacks and allow the wearer to inflate large airbags in a matter of seconds with the pull of a handle. This helps prevent burial and so significantly increases your chances of surviving getting caught by an avalanche.
Regardless of brand, all avalanche airbags work on the same principle; referred to in scientific circles as the principle of Inverse Segregation. Put simply, this states that when in motion, larger objects will always move to the top. This is also true of an avalanche. By inflating large airbags, avalanche airbag packs significantly increase your volume and help keep you on top of an avalanche rather than getting buried underneath.
This phenomenon is also referred to as the "Brazil Nut Effect" based on the fact that in a container of mixed nuts the largest nuts (the Brazil nuts) will find their way to the top. The same is true for muesli, where the larger bits of fruit and nuts always end up on the top. So next time you're enjoying a bowl of muesli, grab the pack, give it a shake and you can marvel at the wonders of Inverse Segregation in action!
Although the method of inflation and the design of the airbags differ slightly from brand to brand, the mechanisms for inflation share the same general principle. The airbag is stowed in a specific compartment in the pack; it is triggered by the wearer pulling a handle. This initiates the system mechanism which causes the airbag to inflate, with extra air being drawn into the system by the Venturi effect. This effect sees the velocity of the gas increase as it flows through a narrowing, while the pressure decreases. A Venturi can use this negative pressure to draw extra air into the primary flow, helping to fill the airbag in a matter of seconds.
When buying an avalanche airbag, a major consideration will be what type of system the airbag uses. Two main types exist, canister systems using canisters of compressed gas to fill the airbag, and electronic systems using electronically powered fans to fill the airbag.
Traditionally airbags have been inflated by using a canister/cylinder of compressed gas (air or nitrogen). In these systems, the pulling of a trigger handle causes the canister to be pierced. The resulting rush of gas from the canister starts the Venturi effect.
There are several canister-based systems used by different brands. Each brand uses its own specific canister – they are not interchangeable between brands even if they look similar! These canisters require replacing or refilling (depending on design) after use.
Most used in Europe where they are approved to fly with, these canisters are compact and lightweight. Used canisters need to be replaced. This can be done at participating retailers and partner centres where customers can exchange their used canister for a new one for a small charge.
These larger canisters are filled with compressed air and can be discharged and refilled, as necessary. They are refilled from large, compressed gas tanks using a special adaptor. This service can be carried out by approved centres, including core retailers, resorts and even some dive/paintball shops. They are predominately used in America, where TSA legislation means you can’t take pressurised canisters on a plane. Using the refillable format, you can fly with an empty canister and refill when you arrive.
- Very reliable, easy to visually check and operate
- Lightweight and compact – the lightest systems are all canister based
- Lots of brands and designs use this system, giving plenty of choice regarding pack styles and features
- Requires canisters to be refilled/replaced after use
- Flying with them needs careful planning as canisters are regulated
Avalanche airbag backpacks using an electronic system offer an alternative to the traditional canister-based system. Rather than relying on compressed gas canisters, these systems use electronically powered fans which start the Venturi effect that fills the airbag.
An electronic system encourages regular practice with the system as there is no hassle with replacement canisters. This is a key benefit as regular training is necessary to become familiar with the system, and to be able to act quickly and intuitively in an emergency.
- Hassle-free user practice
- Travel-friendly design
- Self-testing diagnostics clearly highlights system status
- Weight – heavier than most canister systems
- Cost – high initial purchase price (although no need to purchase additional canisters)
Li-ion Battery or Supercapacitor
There are now two different types of electronic systems available: Li-ion battery powered systems and supercapacitor powered systems. Both use fans to fill the airbags, but they feature different power delivery methods.
Supercapacitors are passive electronic elements. Unlike Li-ion batteries, they store electrical energy without any chemical reaction, so are not subject to any restrictions for transport, shipment, or storage. They are also not sensitive to lower temperatures, meaning you get the same performance from -30°C to +40°C and are lighter than current battery options.
Although larger and heavier than supercapacitors, Li-ion batteries offer more power. This enables a higher number of deployments off a single charge, the option for a larger airbag, and innovative features, such as the ability to maintain airbag integrity in the event of a puncture. Li-ion batteries do have some restrictions when it comes to travel and shipping but the capacity of the batteries in avalanche airbags allow for them to be transported on a plane in cabin luggage.
Considerations When Buying
An Avalanche Airbag Backpack
The type of airbag system an avalanche airbag backpack uses is likely to be the most important factor in your buying decision. Hopefully, you will never have cause to pull the trigger and activate the airbag; however, you will spend lots of time wearing the pack. So how it performs day-in-day-out and the additional features it has, will play a big part in your enjoyment of the product. Here are some other things you should consider when choosing an avalanche airbag backpack.
Consider what type of skiing you will be doing and then align the capacity of your chosen pack with your intended use. For example heli accessed sessions or freeriding within close proximity to lift accessed terrain requires you to carry significantly less kit than if you were heading out on a full day tour into the backcountry. Below is a rough guide to capacities, this is a guide only as individual requirements/preferences differ:
- Lift served backcountry, heli & cat trips: 15-20L
- Day touring: 20-35L
- Multi day touring: 35L+
Size & fit
As with any technical backpack, it needs to fit well and be comfortable to carry. On some models, the position of the airbags after inflation is important, so it is vital to get a pack which fits your torso correctly. A well-fitted backpack will also ensure the correct positioning of the trigger handle; so that it is easy to reach and pull.
If size options are available, make sure you check out size guides to get the right fit. Where possible, we recommend heading into one of our stores where our staff can help you select the right model.
For longer tours and lots of up-hill work, choosing the lightest pack possible will be very attractive. However, lighter weights generally come at the cost of durability and features, so it is all about compromise. If you are planning to spend more time going down than up, then you may prefer to carry some extra weight in return for a burlier pack that can take a bit of abuse.
Traveling With An Avalanche Airbag Pack
Avalanche airbag packs which use electronic systems are well suited to travel, as they do not contain any compressed gas canisters or explosives. The Li-ion batteries included in battery power systems are currently all under the watt-hour threshold for carry-on luggage. Electronic systems powered by supercapacitors are even easier to transport. As they store energy without any chemical reaction, they are not subject to restrictions on transport, shipment, or storage.
More careful planning is required before flying with a canister-based system. The pressurised canisters used in avalanche airbags are classed as hazardous goods, and their transportation by aircraft is subject to restrictions and regulations. Thankfully, an International Air Transport Association (IATA) regulation exists, permitting one canister per person for use with an Avalanche Rescue Backpack.
Before buying your ticket, you should check your airline and airport rules. Different airlines have different policies, and regulations change depending on where you are heading. For example, European, American, and Canadian regulations all vary.
Prior approval is often required by the airline, and it is recommended that you notify them when booking your flight, or at least 14 days in advance. It is advisable to refer to your pack as an ‘avalanche rescue backpack’ as this is how it is described in the regulations. When flying, you will need to make sure that the pack is stored in a manner that prevents accidental activation. The canister must not be screwed in, and the activation handle must be removed/stowed. It can be useful to include a copy of your avalanche airbag safety manual, canister datasheet and IATA information with your pack.
Travelling to or from the United States
If you are travelling to or from North America, the U.S. Transportation Security Administration (TSA) will not allow your pressurised canister on board. You will either need a canister that can be discharged so that you can fly with it empty or look to hire a canister on your arrival.
The availability of support in the form of canister hire, refill, and exchange programmes also vary by location. So, it's worth checking in advance if you are going to need access to replacement canisters while you are away.
For canister-based systems, you need to consider how you will manage replacement canisters. Airbag packs use specific canisters, and these aren’t interchangeable between brands. It is crucial to know which canisters your system uses and only purchase genuine replacements from an approved dealer.
Once you set off your airbag – either in an avalanche scenario or a practice deployment – you will need to source a replacement canister. Luckily, it’s a straightforward process, but it will require some planning so that you don’t get stuck without a canister.
The version primarily used in Europe is the smaller non-refillable version, which meets IATA regulations to be allowed on-board an aircraft. After deployment, this will need to be returned to the manufacturer for refilling. There is an extensive canister exchange programme in place for this. Customers can take their used canister into participating retailers and exchange it for a new one (a service charge will apply).
The larger refillable version is primarily used in the States where flying with the smaller canister is prohibited. This version has a pressure gauge and can be refilled from a compressed gas tank using a special adaptor – either at an approved retailer or dive/paintball shop. This means the canister can be emptied before flying and then refilled on arrival, allowing users to meet TSA regulations.
Mammut Canister Exchange
Ellis Brigham is part of Mammut’s canister exchange programme. We offer customers the opportunity to exchange their used canisters for new ones, with a small refill charge.
This only applies to the Mammut/Snowpulse non-refillable canisters that are compatible with Mammut’s Removable Airbag System and Protection Airbag System, and Snowpulse avalanche airbags from the 2011-2012 winter season.
This exchange can only be done in-store, and we cannot offer an exchange for any other style or brand of canister.
Avalanche Airbag Backpacks
Take a look at our other buying guides
The best ski is the one most suited to your ability and the kind of terrain you intend to ride. Choosing the right skis is a simple matter of balancing the shape, flex and characteristics to your requirements.