Didier Delsalle successfully landed a helicopter on the summit of Everest, the highest mountain in the world. Delsalle completed this record breaking task, twice in two day (May 14th and 15th 2005). These flights set the new World Record for the highest altitude take-off. Eurocopter (Eurocopter.com) designed the helicopter.
Email from Didlier Delsalle to Spadout
Delsalle: The first thing that has to be said is that the Everest feat was part of a general research project concerning a very high altitude helicopter version being able to rescue people at altitudes up to 8000 meters. The purposes of the Everest flight tests campaign were for us to gather as many data as possible and to demonstrate what we can do today with a production helicopter and to gather as many data as possible to design a future specific helicopter. We have been able to go on Everest summit but at the arrival in Nepal, this was not taken for granted, it was just a possibility we eventually looked for. The goal was only to try to land as high as we could with an acceptable level of risks.
8000 meters altitude is the average maximum altitude where a rescue by helicopter can reasonably be hoped as efficient and successful considering today's state of art of helicopter designing. Of course, this depend highly on the landing area, a summit with a roughly round shape like the Mont Blanc summit or a "col" (a saddle) for example is easy to land on but to make a peak hover landing, i.e. to maintain contact with a sharp summit with just a part of a landing skid, is much more difficult. Another way of rescuing people is to hoist them in hover, in this case the power needed to hover is very high and we reach the engine limits at these altitudes.
The behavior of the helicopter at such high altitudes is not well know at all, the air is so thin that a lot of things are impacted, rotor lift and response, engine power and behavior are dramatically changes. For example, to manage the engine turbine temperature at such altitudes is like trying to maintain the milk inside a full boiling milk pan!
The other criteria which will make a rescue possible or not is the weather conditions because you have to deal with Nature there, Mother Nature will decide for you if she allows you to go there: from 7000 meters and above you reach what we call the Jet Streams area where winds up to 300 km/h could blow, all the climbers know about these raging winds. So even if the weather is perfectly clear, no helicopter can or will sustain such winds during rescue operations or even fly there. But fortunately, climbers generally choose times of the year when the weather window is acceptable for them to climb, these periods where the winds slow down will be favorable too for rescues if needed but a lot of other conditions can cancel a rescue, clouds, snow and so on.
If one day a rescue operation is requested at these altitudes, people will have to take all these factors into consideration to decide if it is worthy to send a crew to rescue one climber, all the risks shall be evaluated because it will stay a very tough mission even with a powerful helicopter. The Nature forces you may find there can overpower every helicopter capability!
So, when I read in some climber media that it was a wrong thing to go on the top of Everest because it will kill the magic and the human performance to climb agarmatha, and that they are afraid that it will be a common thing to bring tourists there by helicopter, I can say that they can sleep quietly, it is not for tomorrow, and not in a near future. It is and it will stay a very specific achievement for a helicopter, achievement which needs a combination of technology, human skills and a good part of luck!
· 1 decade ago