Heli-skiing is the sport of flying in a helicopter to a high, remote place in the mountains and then skiing down snow that no one else has skied on — deep, fresh snow, far from the usual ski lifts and crowded runs. You need a helicopter, a guide, and a lot of money; it is not a Saturday hobby for most people. The point is the untouched snow and the wild ground, which is also why it can be dangerous (avalanches, sudden weather). You will see it written heli-skiing, heliskiing, or heli skiing; the hyphen is common. Heli- here is short for helicopter, not a science prefix.

直升機滑雪