At the cursing altitude of 747, the air at the top of the Everest is very thin. The Helicopter cannot fly in thin air. It happened only once. On May 14, 2005, Didier Delsalle became the first (and only) person to land a helicopter, the Eurocopter AS350 Squirrel, on the 8,848 m (29,030 ft) summit of Mount Everest.