This problem is afraid a lot of people hold out curiosity ah, actually the answer is 3 words -- do not do! This basically is the factor that has two sides among them. 
The first, helicopter function is insufficient. Helicopter can enter the space, advocate the lift that if rely on ala coming back to rotate in air,arises, because altitude jumps over tall local air,jump over rare, the lift that ala coming back can produce below same rotate speed is smaller, want to raise lift to be able to increase engine rotate speed only, but what use as a result of helicopter is fuel engine (engine of turbine wheel shaft) , when work engine needs oxygen to share combustion business, and content of the oxygen in taller air exceeds height above sea level low, current helicopter engine accomplishs full power movement impossibly, rotate speed of ala coming back rises impossibly also, restricted the promotion of lift, react with human highland same, anoxic, do not have interest. 
So although at present the world record of helicopter ceiling is as high as many meters 12000, but that is special the helicopter that change one's costume or dress obtains below ultimate circumstance, on eye preexistence bound besides 9 besides basically all helicopter do not have the capacity that flies to 8000 meters of headroom, although those 9 reluctance can fly on this height, sure also lost carring capacity ability, hold at the same time charge a sex exceeding also drop, become very poor, never mention it below this kind of circumstance come to help or carry goods and materials, can safety flies to fly to be able to have said again is a miracle. 
The 2nd, environmental element. Change of the weather on Mount Everest is very frequent and acuteness, air air current is very complex and disorder, helicopter is held hard in such environment accuse, it is normal to do not have method to ensure at all fly, security extreme difference, it is even dangerous to can say to ascend a top than manpower much, more come to help to need to be begun below soup normally what is more,the rather that, so this kind of task finishs impossibly namely to current helicopter.
