Why CANT a helicopter fly to mt Everest?

Answer 1

Helicopter blades work like modified wings. They create a vacuum above the blade and push down the air below the blade. In order to work, there must be enough air to create a vacuum above the blades and enough air for the blades to push down. Try sitting in an arm chair. Put your hands on the arms. Now get up as you push down on the arms. Now try sitting on another chair the same height with your legs in the same position. Which is easier to get out of? Without having enough air to push down, a helicopter can not go up.

Answer 2

The air is too thin. The blades would have nothing to hold them up.