The barrel fly-out system consists of a series of barrels that collect the waste. The barrels are removed by helicopter and transported to a proper waste disposal facility. The strength of this system is that it totally removes waste from sensitive alpine ecosystems. Disadvantages are that helicopters are expensive, noisy, and use fossil fuels. In addition, there is a risk potential for spills during transport, and a health risk for maintenance personnel.
The Alpine Club of Canada. Used in many of their alpine huts.