This achievement is most easily done in free ride, as you can pick an area to attempt this in without any trees or rocks to get in your way. While Speed Riding, press
to take off, then hold
to brake and land safely, as you would while parachuting under normal circumstances. Try to hit the ground with your skis and not your body, and make sure you aren't traveling too fast when you take off or land, because otherwise the G-force from landing will cause you to wipe out. Fortunately, you don't need to get a lot of air for it to count as "taking off." Do this five times in the same run without falling, and the achievement is yours!