This trick easier than it looks. You have to know how to B/S Half-Cab first. Go at a pretty fast speed and setup like a B/S Half-Cab except put your front foot at the start at the first bolts. So it doesn't cover any bolts but its as close to them as possible. Then pop down and do a B/S Half-Cab its better if you can do more than a 180 but it doesn't matter that much. When your dragging drag up until your front foot is on the nose. Then land on a nose manual and quickly pivot the other 180. I learned this trick in about 2 hours or so but it shouldn't take that long. Its quite an easy trick.
Why not just call it a nollie 360 instead of giving it a silly name? Or a nollie cab.
I call nollie cabs nollie 360's. I dont use the name helipop as it sounds absolutely retarded (even if thats what freestylers used to call them). Flip skater03158 wanted to know what the helipop was though.