heliskiing is legal in some federal states, some shots in freeski movies are shot in the ski resort of st.anton, and its truly heliskiing. i think its legal in vorarlberg (silvretta nova, one part of the resort arlberg/st.anton, diedamskopf, damüls), but sure as hell illegal in tirol (ischgl, the rest of st.anton/arlberg, mayrhofen, sölden, kaunertal, hintertux)
dont no about switzerland