The race leaders need to get up high to round the Mont Blanc massif, with the summit of this magnificent mountain at 4808m. That means the athletes will have to fly as high as possible. The higher they fly, the tighter they can round the mountain over the west side, as the Turnpoint 9 Mont Blanc requires. Currently, cloudbase is at around 3500m, which means that is the maximum height at which athletes can fly.