the true take off altitude is 4810m. the highest take off in Europe
Access
this take off needs experience in alpinism. You need to sleep in a refuge around 3800M and after that walk with rope, ice axe, and crampons for 6hours... you climb on a glacier with crevasses... only for sportif people!
Rules
July-August: restricted area flight see website https://federation.ffvl.fr/actu/r-glementation-vol-libre-dans-massif-mont-blanc
WEATHER
best conditions are with slow winds from the north.