Why can’t we use helicopters to rescue climbers on top of Mount Everest?
In: Physics
Helicopters work by pushing a mass of air downwards to create a lifting force. In order to fly you have to create a lifting force equal to weight of the vehicle. If the density of air goes down, the amount of mass available to push decreases, and the max amount of lifting-force you can generate also goes down. Since density of the air goes down with altitude, the ability to create lift drops off with altitude. You can spin the rotors faster in-order to compensate for this, but there is a limit to that too. The tips of the rotors cannot exceed the speed of sound without causing a lot of problems. Therefore, there is an altitude ceiling at which a helicopter can no longer fly at. Mount Everest is well above that ceiling
Latest Answers